# Non Pro's - do you use a Paint Thickness Gauge



## cptzippy (Apr 4, 2012)

Don't want to spend the money on a Paint Thickness Gauge but I'm also nervous about going aggressive with the polish on my Old Jag without one. One catch is, as a non-pro, this very well might be the only time I use the thing (PTG).

So, weekend warriors and hobbyist detailers - do you use a PTG? especially you guys and gals out there like me that have older cars.

TIA,
Tony


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## The Cueball (Feb 8, 2007)

yes, I have one and use it on every car....

cheaper than a re-paint IMO

:thumb:


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## OldskoolRS (May 5, 2011)

No, but then I have my own spray gear as well...


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## turboyamaha (Nov 18, 2010)

OldskoolRS said:


> No, but then I have my own spray gear as well...


Interesting!


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## Scott_VXR (May 22, 2011)

No...but I do it 'by the book' and don't do anything tooo stupid :thumb:


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## cptzippy (Apr 4, 2012)

Scott_VXR said:


> No...but I do it 'by the book' and don't do anything tooo stupid :thumb:


Well, that let's me out - d'oh.


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## -Kev- (Oct 30, 2007)

without insurance, on other peoples cars its a must imo. they are'nt fool proof (a particular area may show a high reading but there could easily be body filler lurking...) but they'll still give you idea of what there is 'to play with' and where a car may of been repaired before..


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## PugIain (Jun 28, 2006)

Nope.Not got one.Ive machined my own cars,but have always been sensible enough not to go too mental.


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## bigmc (Mar 22, 2010)

No, not got one but I use P1 with much respect and don't do cars for anyone else any more, I do my mum and dads but they're little more than a quick spruce with P1 on a finishing pad, a glaze and a wax/sealant. Wouldn't go anywhere near a paying customers car without one though.


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## stangalang (Nov 27, 2009)

No.........

















I use 2 :lol:


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## alxg (May 3, 2009)

Just posted in your other thread but I say yes, I have one and use it to quickly check over cars I do enhancements on (you never know) and then if doing more correction type jobs I use it more throughout too.

Just the one mind you, people who use more than that are the kind of folk your mum warned you about :lol:


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## Andrew125 (Apr 2, 2012)

They are incredibly expensive from what I have seen but I guess its cheaper than a strike through..


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## -Kev- (Oct 30, 2007)

not all are andrew - the ones that can measure plastic panels and / or each paint layer cost £1000's, but the ones most on here use that measure metal only and the total thickness costs about £150-180ish, depending where its from..


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## cptzippy (Apr 4, 2012)

Andrew125 said:


> They are incredibly expensive from what I have seen but I guess its cheaper than a strike through..


The one recommended to me is the Highline II for $250 US.


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## cheekymonkey (Mar 15, 2008)

stangalang said:


> No.........
> 
> I use 2 :lol:


show off :lol:


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## cheekymonkey (Mar 15, 2008)

if you are doing other peoples cars its a must IMO.


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## Nanoman (Jan 17, 2009)

Yes. How else will you know how many microns that last pass took away. They're not foolproof but give you a good idea what you are working with?


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## Adrian Convery (May 27, 2010)

Yes, they are fantastic, so useful when buying a second hand car also to see if it has ever seen any paint before!


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## Mr Face (Jan 22, 2009)

Like a condom, its a must have if you are removing paint ot clear coat, if not and you go through you got rust nine months later :wall:

If its a one off can you find a local who has one & buy him a drink while you zip around the jag taking readings ?


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## PugIain (Jun 28, 2006)

Mr Face said:


> if not and you go through you got rust nine months later :wall:


Rust from removing clear??
Maybe on something not French.I repaired a deep scratch on the sill of my 406 and didnt put any clear on,it didnt rust.I had that 5 years,and my brother now has it.It's still ok.
Might rust if you go through,clear (if present),paint and primer and then left it for a few weeks.But you'd have to be a moron of biblical proportions to manage that one.


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## dhiren_motilal (Apr 3, 2011)

"..nine months later your have rust.." GOLD


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## Leemack (Mar 6, 2009)

Elephant in the room lol

I ddn't a fair few years ago and yup, I thought FCP on a green 3m pad was the way to go. Bye clearcoat

First and last time i did it. We all make mistakes and that was years ago so for the sake of £175 it was worth it as i paid £1200 to fix my fk up (on a mates car aswell)

Mistaes happen but minimise the risk from day 1 imo


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## bero1306 (Jan 24, 2011)

No. Overboard imo when I'm using a DA once a year.


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## bigmc (Mar 22, 2010)

Mr Face said:


> Like a condom, its a must have if you are removing paint ot clear coat, if not and you go through you got rust nine months later :wall:
> 
> If its a one off can you find a local who has one & buy him a drink while you zip around the jag taking readings ?


You wear a condom when removing clear/paint? Strange, never heard that one before??:doublesho:doublesho


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## OldskoolRS (May 5, 2011)

bigmc said:


> You wear a condom when removing clear/paint? Strange, never heard that one before??:doublesho:doublesho


Perhaps he uses a different tool to measure his paint? :lol:


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## Dixondmn (Oct 12, 2007)

bigmc said:


> You wear a condom when removing clear/paint? Strange, never heard that one before??:doublesho:doublesho


we were taught at school to 'Always wear a Condom"

I'm wearing one now.


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## TOGWT (Oct 26, 2005)

Using a paint thickness gauge gives a professional detailer credibility and also acts as an insurance against 'break-though' of a clear coat, which would entail an expensive re-paint and I suspect a very irate customer.

Original paint has a better resale value than a re-painted vehicle, plus they will lose the use of their vehicle for some days. The ideal setup would be a DFT Combo for the metals and a PosiTector 200 B/Adv for the composites

Clear Coat Thickness and UV Protection Removed by Polishing - http://www.autopia.org/forum/guide-...ness-paint-removal-polishing.html#post1448231


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## Bratwurst (Jan 23, 2009)

I own a PTG and use it every time I do a car. Only do family and friends, and to me messing up one of those would be worse than some dude I don't know, so yes a PTG is a must beyond your own car. If it's only your car... well take your chances and accept whatever happens.
I'm by no means at all a 'detailer', but I do like to do my best by my car(s) so I would say I'm a keen hobbyist and no more. The day I bought and tried my DA, I knew I HAD to get a PTG really only through the realisation that I was dealing with the unknown. A PTG can give you a lot of useful knowledge and save you BIG money.
The way I looked at it and justified it's purchase; all it needs is one panel on one car that has either a thin area or a smart repair and you burn through... that repair you then need will be easy the cost of a PTG. Then think about how many panels you intend on doing where you know next to nothing about their history...


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## 123quackers (Jan 29, 2009)

YES, I I use a PTG on other peoples cars, it's the cheaper option in the long run...:thumb:


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## cptzippy (Apr 4, 2012)

Ended up getting the Highline II meter. Not fancy but comes highly recommended.


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## josadler (Jul 14, 2010)

I use a cheap PTG only for my cars. As already said, it's cheaper then having a respray and although my cars have a healthy level of clearcoat, a few places where deeper scratches have been removed have a less safe clear coat thickness


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## Daz118 (Apr 10, 2012)

Would I need to use a paint guage before using a da to remove light swirls or is it not as importiant with a da as it is with a rotary?

Sorry for being such a noob


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## Bill58 (Jul 5, 2010)

Daz118 said:


> Would I need to use a paint guage before using a da to remove light swirls or is it not as importiant with a da as it is with a rotary?
> 
> Sorry for being such a noob


I would always advise someone who wants to carry out paint correction to use a PTG. Paint correction could have been carried out in the past and the topcoat could be just a few microns thick leaving no depth for correction.


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## alexj (Apr 12, 2012)

*Thinking of getting one maybe sometime down the line,

any recommendations for one thats worth having and easy to use without breaking the bank

or is it a case of you get what you pay for ? *


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## Bill58 (Jul 5, 2010)

alexj said:


> *Thinking of getting one maybe sometime down the line,
> 
> any recommendations for one thats worth having and easy to use without breaking the bank
> 
> or is it a case of you get what you pay for ? *


This is the one I bought http://www.detailingworld.co.uk/forum/showthread.php?t=169842&highlight=paint+detective+pd8


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## JakeWhite (Oct 14, 2011)

My attitude is on your own car it's your own choice but on anyone elses (especially paying customers) they are an essential bit of kit to have and don't cost the earth, especially when compared to a re-spray. Even if it's just on your car they're worth having as you don't always know the history of the paint and with one you can keep track of what you got left to play with


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## Daz118 (Apr 10, 2012)

We have 2 at work for warranty paint claims (main dealer garage) so I will see if I can borrow one and check out my car. I have had it from new so it should be ok but best to check then


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## alexj (Apr 12, 2012)

Thanks for that Bill, Jake and Daz

One was used on my car last month before it was detailed, was a bit worried as I didnt want to hear it might have been in a shunt

Thankfully it hadnt and was fine


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## rnwd202295x (Mar 19, 2011)

cptzippy said:


> Don't want to spend the money on a Paint Thickness Gauge but I'm also nervous about going aggressive with the polish on my Old Jag without one. One catch is, as a non-pro, this very well might be the only time I use the thing (PTG).
> 
> So, weekend warriors and hobbyist detailers - do you use a PTG? especially you guys and gals out there like me that have older cars.
> 
> ...


I've got one. Bought in partnership with a mate. Got it on this forum in a Group Buy.

Its a must for any correction :thumb:


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## StuaR32t (Jun 6, 2009)

Am I the only one that thinks it might be over kill if you're just using a DA?

If you start off with the finest polish and finest pad combo then chances are you are not going to get rid of all fine swirls? Then progress through different polish/pad combos until you get rid of them. If you know you're only just getting rid of fine swirls then you know you're not removing a lot of clearcoat. 

I'm no pro at this but progress with caution and you'll be fine.


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## james_death (Aug 9, 2010)

Did my own motor without one, but saved and sold some bits on flea bay to buy one.

Just ask your self if you had the money to spare would you buy one?

I think everyone would as they make sense.

Even then its for the overall reading no way could i afford the ones that take all the reading depths for all including plastics.

You could do your own motor and then sell it on.

There may be a fellow member close by willing to come and take readings with you?

Your free to do whatever you wish with your own property.

Much happier myself to have one.


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## Titanium Htail (Mar 24, 2012)

If it were me, I would make a donation to any member who did as James suggested and that would go towards the initial cost. Spare, I have three rusty teenagers.


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## Bill58 (Jul 5, 2010)

StuaR32t said:


> Am I the only one that thinks it might be over kill if you're just using a DA?
> 
> If you start off with the finest polish and finest pad combo then chances are you are not going to get rid of all fine swirls? Then progress through different polish/pad combos until you get rid of them. If you know you're only just getting rid of fine swirls then you know you're not removing a lot of clearcoat.
> 
> I'm no pro at this but progress with caution and you'll be fine.


If you don't know how much clearcoat you have to work with then you don't know what you can safely remove. The car could have been previously machine polished leaving very little clearcoat. Even some new cars can come with very little clearcoat.


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## CliveP (Feb 1, 2009)

Yes I have one and yes I use it on every machine polish.

For less than one month's council tax (OP - which is a UK housing tax), or for less than one month's depreciation on my car, for something that might tell me there's an issue before I polish, should last a lifetime, makes my hobby more fun, I think a PDG is cheap as chips!

Regards,
Clive.


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## organisys (Jan 3, 2012)

StuaR32t said:


> Am I the only one that thinks it might be over kill if you're just using a DA?
> 
> If you start off with the finest polish and finest pad combo then chances are you are not going to get rid of all fine swirls? Then progress through different polish/pad combos until you get rid of them. If you know you're only just getting rid of fine swirls then you know you're not removing a lot of clearcoat.
> 
> I'm no pro at this but progress with caution and you'll be fine.


Depends, park the DA in one spot, or edge the pad with an aggressive polish...OK extreme examples, but even the Megs MF system on DA can remove more than you might expect according to people on here who have tested it.


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## moosh (May 8, 2011)

I've been machining cars for 15 years and never needed one :thumb:


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## Nanoman (Jan 17, 2009)

moosh said:


> I've been machining cars for 15 years and never needed one :thumb:


How do you know?


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## moosh (May 8, 2011)

Nanoman said:


> How do you know?


I know how to use a machine polisher and under stand my products and pads and the paint I am polishing, I was a painter to trade and we were taught refinishing in college as part of our course. PDGs were never used and still not used in bodyshops when polishing they are mainly used in warrenty work to check if panels have been painted previously.when polishing a car its all about (imo) properly inspecting the paint work prior to polishing, it really is not that scientific. Panel expands and contracts when heated and cooled so PTGs can be inaccurate but I don't disagree with people who use them.


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## Nanoman (Jan 17, 2009)

moosh said:


> I know how to use a machine polisher and under stand my products and pads and the paint I am polishing, I was a painter to trade and we were taught refinishing in college as part of our course. PDGs were never used and still not used in bodyshops when polishing they are mainly used in warrenty work to check if panels have been painted previously.when polishing a car its all about (imo) properly inspecting the paint work prior to polishing, it really is not that scientific. Panel expands and contracts when heated and cooled so PTGs can be inaccurate but I don't disagree with people who use them.


Fair enough. I wouldn't let anyone near my car without one though. I'm not sure it's possible to have any idea how much you've got to play with without one. I'm also not sure anyone can know how much prescious clearcoat they're removing without one.

I'd be interested to hear your thoughts...


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## moosh (May 8, 2011)

Nanoman said:


> Fair enough. I wouldn't let anyone near my car without one though. I'm not sure it's possible to have any idea how much you've got to play with without one. I'm also not sure anyone can know how much prescious clearcoat they're removing without one.
> 
> I'd be interested to hear your thoughts...


I can appreciate your thoughts, its something I've never had to worry about because with being a painter and painting cars you just know what you've got, I can tell by looking at what the paint type is like and 9/10 select the right combo to replenish the paint finish. In the 15 year I've been involved in the paint trade I've seen a PTG twice . It's a fear we have never had and I guess the professional training helps with that without being disrespectful to anyone.

When you say its hard to tell what you have to play with, how does the PTG separate the different paint stage depth I.e. galvanized coating, etch coat, primer, base coat and finally Clearcoat? I don't think it can and even worse than that imo you get a car with several different readings? So has it had paintwork on some panel hence the high readings or has it been poorly cut & polished on other panels hence the low readings?

How do we determine what our clear coat depth is? These are the types of questions that arise when I think about PTGs and I've thought about buying one many times but I just feel like the 3m sungun that its just another tool that detailers have grabbed to make detailing more of a profession than a skill. I say that with respect as I would class myself also as a detailer as well as a painter (previously).

The 3m sungun for reference was designed originally to check colour matching when blowing in and blending paint work. The intense light helps to check pigments, metallic flake and mica/pearls have been layered and blended correctly. Detailers use them to spot swirls which I'm sure most will agree there are alternatives at a 10th of the cost albeit they may not look so pro but the 3m sungun might help to justify some peoples days rates.


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## TOGWT (Oct 26, 2005)

^^^ I take my hat off to anyone who can tell just by looking how many microns of paint there is


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## -Raven- (Aug 26, 2010)

TOGWT said:


> ^^^ I take my hat off to anyone who can tell just by looking how many microns of paint there is


Do you need to though? PDGs are just a guide, nothing more.


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## moosh (May 8, 2011)

TOGWT said:


> ^^^ I take my hat off to anyone who can tell just by looking how many microns of paint there is


Thanks fella you can pop your hat back on :thumb:


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## avit88 (Mar 19, 2012)

moosh said:


> I can appreciate your thoughts, its something I've never had to worry about because with being a painter and painting cars you just know what you've got, I can tell by looking at what the paint type is like and 9/10 select the right combo to replenish the paint finish. In the 15 year I've been involved in the paint trade I've seen a PTG twice . It's a fear we have never had and I guess the professional training helps with that without being disrespectful to anyone.
> 
> When you say its hard to tell what you have to play with, how does the PTG separate the different paint stage depth I.e. galvanized coating, etch coat, primer, base coat and finally Clearcoat? I don't think it can and even worse than that imo you get a car with several different readings? So has it had paintwork on some panel hence the high readings or has it been poorly cut & polished on other panels hence the low readings?
> 
> ...


i like this guy!


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## Bratwurst (Jan 23, 2009)

Still won't stop me from using one.

Each to their own and all that, but from my point of view (as someone who doesn't have all those years 'in the trade' or the eyesight that can tell all about a paint) I think I'll stick with my machine that's served me so well in the past.


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## Swift Sport 60 (Sep 24, 2011)

I've never used one and I've never had a problem and I'm always wetsanding scratches. I've also wetsanded body panels and an entire golf r32.


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## B-mah (Oct 4, 2011)

I have one, will use it when the bloody rain stops for 2 minutes and i can have a go at the car.


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## Clark @ PB (Mar 1, 2006)

TOGWT said:


> ^^^ I take my hat off to anyone who can tell just by looking how many microns of paint there is


Agreed.

And no offence intended to anyone in here but just because you've been machining for "X" amount of years doesn't mean you've been doing it correctly.


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## macmaw (Mar 5, 2007)

moosh said:


> I can appreciate your thoughts, its something I've never had to worry about because with being a painter and painting cars you just know what you've got, I can tell by looking at what the paint type is like and 9/10 select the right combo to replenish the paint finish. In the 15 year I've been involved in the paint trade I've seen a PTG twice . It's a fear we have never had and I guess the professional training helps with that without being disrespectful to anyone.
> 
> When you say its hard to tell what you have to play with, how does the PTG separate the different paint stage depth I.e. galvanized coating, etch coat, primer, base coat and finally Clearcoat? I don't think it can and even worse than that imo you get a car with several different readings? So has it had paintwork on some panel hence the high readings or has it been poorly cut & polished on other panels hence the low readings?
> 
> ...


A lot of these are questions which tell you exactly why you should indeed be using a PTG, and some of the PTGs can in fact determine separate layers, but in our case we are only intersted in the top layer - the clear coat in most cases.
You could never convince me that just by looking at a car you could tell me how thick the clear coat was, if it had ever been machined before & how much was left? Or how much you had removed yourself?
I'm sure you could spot a respray no problem.


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## PaulN (Jan 17, 2008)

Ive got the Standard PTG, it does give a good idea of whats going on.

The sub £200 are still great but really arent ideal, Id really love a split coating gauge but for me £1000+ could be spent elsewhere.


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## macmaw (Mar 5, 2007)

In addition to the above, to answer another question, "how do we determine what our clearcoat depth is?"
If you are using a non composite PTG, then a good rule of thumb would be to take readings on the parts that are not clear coated, such as under the bonnet, under the boot, insides of doors etc, then take a reading on some bits that have been clear coated nearby. An average of these readings minus the average of your first readings would give an idea of the clear coat thickness.


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## Bratwurst (Jan 23, 2009)

Swift Sport 60 said:


> I've never used one and I've never had a problem and I'm always wetsanding scratches. I've also wetsanded body panels and an entire golf r32.


:doublesho:doublesho

Well I hope whoever buys your car has a PTG then


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## moosh (May 8, 2011)

macmaw said:


> In addition to the above, to answer another question, "how do we determine what our clearcoat depth is?"
> If you are using a non composite PTG, then a good rule of thumb would be to take readings on the parts that are not clear coated, such as under the bonnet, under the boot, insides of doors etc, then take a reading on some bits that have been clear coated nearby. An average of these readings minus the average of your first readings would give an idea of the clear coat thickness.


So tell me this fella if you read my original post, there's on average 5 different layers from etched coat to clear coat and these are on all the panels of the main body and for your info under bonnets on a lot of cars these days are painted in a different fashion so unless you know this make up you would be hard pushed to come up with any averages.

Further more your theory of using inside of the doors to test, that makes no sense because in there is the same paint make up as the interior? If it had no clear it would not be shiney and wash off as modern paints are waterbased.


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## moosh (May 8, 2011)

TOGWT said:


> ^^^ I take my hat off to anyone who can tell just by looking how many microns of paint there is


At no point did I could say I can count microns with my eyes I don't think you read my post the way it was intended to read.



Clark @ PB said:


> Agreed.
> 
> And no offence intended to anyone in here but just because you've been machining for "X" amount of years doesn't mean you've been doing it correctly.


I've been doing it correctly but we could go round in circles all day,Clark tell me how you work out from your ptg reading what depth your etch is, your primer, your base coat is and your Clearcoat? I would class myself as a professional because I have a qualification in vehicle repair & refinishing.



macmaw said:


> A lot of these are questions which tell you exactly why you should indeed be using a PTG, and some of the PTGs can in fact determine separate layers, but in our case we are only intersted in the top layer - the clear coat in most cases.
> You could never convince me that just by looking at a car you could tell me how thick the clear coat was, if it had ever been machined before & how much was left? Or how much you had removed yourself?
> I'm sure you could spot a respray no problem.


I'm not trying to convince you not to use one and by your posts its clear you should use one if it make you confident in polishing.


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## Bratwurst (Jan 23, 2009)

Does it matter about all the paint below? 

I couldn't give two hoots how much etch primer's on a panel, I'm not trying to correct etch primer. Who is?

It's only the clear we're interested in (on a clearcoated car) and a PTG DOES help you calculate _roughly_ how much you have there.

Looking at it and guessing seems like your pi55ing in the wind frankly.


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## maersk (Sep 6, 2007)

'If it had no clear it would not be shiney and wash off as modern paints are waterbased.'

Lets not get too silly in this discussion,................. please.


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## moosh (May 8, 2011)

maersk said:


> 'If it had no clear it would not be shiney and wash off as modern paints are waterbased.'
> 
> Lets not get too silly in this discussion,................. please.[/QUOTE
> 
> True story


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## moosh (May 8, 2011)

wee_green_mini said:


> Does it matter about all the paint below?
> 
> I couldn't give two hoots how much etch primer's on a panel, I'm not trying to correct etch primer. Who is?
> 
> ...


ofcourse it matters, so your cutting microns off on say paint as thin as 90 microns? How do you know how much clear you have to play with?


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## Bratwurst (Jan 23, 2009)

moosh said:


> ofcourse it matters, so your cutting microns off on say paint as thin as 90 microns? How do you know how much clear you have to play with?


We're just going round in circles here...

By doing this kind of thing:



macmaw said:


> In addition to the above, to answer another question, "how do we determine what our clearcoat depth is?"
> If you are using a non composite PTG, then a good rule of thumb would be to take readings on the parts that are not clear coated, such as under the bonnet, under the boot, insides of doors etc, then take a reading on some bits that have been clear coated nearby. An average of these readings minus the average of your first readings would give an idea of the clear coat thickness.


^ The thing that the vast majority of us on here who have a PTG do and have no problems with.

Conversely, I refuse to beleive that even 1% of people on here can tell how thick some lacquer is just by looking at it.

Are you really saying that you can look at the paint on a panel of a car and KNOW how much paint is under the lacquer and also how much lacquer there is, accurately enough for you to then safely wet-sand and/or machine polish that same paint?  On top of that, not beleive the results that a PTG would give you?


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## moosh (May 8, 2011)

wee_green_mini said:


> We're just going round in circles here...
> 
> By doing this kind of thing:
> 
> ...


I think you read the other guys comment and thought right let's have a go at this neep, no where have I said I was a human ptg as suggested. All I was saying is basically I'm not classed as a pro but with 15 year experience and a qualification in vehicle refinishing level 3 SVQ I have the knowledge not to need a PTG.

I also tried to explain why I didn't use one because after all this is what the original thread was about except I got nail with ridiculous questions and statements non of which were correct and when I questioned back no one could answer with fact.

Also I said no offense to anyone using one as they have a purpose its original purpose was for measuring over all depth of paint materials.

What's your average depth of cut because if your good at what you do it should 90% of the time be the same?


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## XRDAN (Feb 28, 2012)

Im interested to know how using a standard PTG helps you establish how much clearcoat you have to work with, many of you seem to use it for this purpose but doesnt the PTG only give you an overall reading of the paint from metal to top? taking this reading and comparing it to a part of the car which doesnt have a full finish such as under bonnet, door shuts etc surely wont help you find out the thickness of clearcoat on a panel??

If one panel gives you a high reading you might think, ok its been painted- there is plenty of clear to work with when really its had a load of highbuild on the repair and little base and clearcoat. On the other hand you could have the same high reading and it could be because its an adjecent panel to a repair which has been blown in with clearcoat and still has a factory finish under that, in which case the extra depth would be clearcoat...

just my thoughts:thumb:


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## -Raven- (Aug 26, 2010)

A PDG wont stop people burning paint.....


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## david_h (Sep 19, 2006)

As has been said, don't do anything stupid and there's no need for one. My view is always if I screw it up totally I only have myself to blame and then I will get it resprayed.

I don't paint correct any cars other than my own.


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## Bratwurst (Jan 23, 2009)

moosh said:


> I think you read the other guys comment and thought right let's have a go at this neep, no where have I said I was a human ptg as suggested. All I was saying is basically I'm not classed as a pro but with 15 year experience and a qualification in vehicle refinishing level 3 SVQ I have the knowledge not to need a PTG.
> 
> I also tried to explain why I didn't use one because after all this is what the original thread was about except I got nail with ridiculous questions and statements non of which were correct and when I questioned back no one could answer with fact.
> 
> ...


Erm, no. I read your comments from the start and thought to myself that it goes against everything I was taught, that's why I've replied. I've not got anything personal against you, so please don't think that I do.

I just can't get my head around how you can say some of the things you do, that's all. You are saying "I have the knowledge not to need a PTG" which infers that you _know_ when you have lacquer to play with and when you don't. If there is this knowledge that means you don't need a PTG, then that same knowledge must be telling you that there is lacquer there and that you have enough of it there to do what you want to do at the time.



moosh said:


> I know how to use a machine polisher and under stand my products and pads and the paint I am polishing, I was a painter to trade and we were taught refinishing in college as part of our course. PDGs were never used and still not used in bodyshops when polishing they are mainly used in warrenty work to check if panels have been painted previously.*when polishing a car its all about (imo) properly inspecting the paint work prior to polishing, it really is not that scientific*. Panel expands and contracts when heated and cooled so PTGs can be inaccurate but I don't disagree with people who use them.


This is the kind of thing you've said too that's making me think the way I am. You are doing a visual inspection of the paint (and by the way I totally agree that this should always be done) but the point is that this is all you're doing. You say too that it's not that scientific... do you mean then that the science of how thick the lacquer is, is of no importance? It is. It's exactly that science that's important.

I'm saying that I *need* one to tell me. And that it works, for me and countless other folk on here.

What do you reckon the ratio of people burning through by not using a PTG is compared to people burning through who have used one is?

To answer your question, it depends on the car, the paint, the defects encountered on the various panels and the work they require to fix. I've made a car look near-on perfect by only removing about 5 microns. I've made a car look only slightly better and removed almost 15 microns, but then stopped due to the removal and the problems it had. I've done some cars and purposely only removed a few because I've had no idea of it's history and to be honest, 5hat it through fear of damage. There's no way I could possibly have judged all of that without a PTG. No way on earth. I know it's only a guide, and an average, and even more so when trying to calculate the actual lacquer thickness but that's exactly the point, it's a guide and it works and it's been proven to work for loads of us on here. If I did all of that without a PTG, I'd have wrecked numerous cars.

I can understand how you can look at paint and see a burnt through area, no problem, that's easy. I can also understand how you can look at a panel and think that it's not lacquered and is single stage. They just have this difference to them. I can't imagine though how you can look at a panel and think to yourself "right I'm going to machine that panel, I'm safe to do so" when you have no idea of (for example) thin, or previously corrected, areas.

By the way, I'm not doubting your experience or the standard of your work. I bet it's way better than anything I've ever done. I'm no more than a keen hobbyist who produces normally average work and only occasionally good work. It takes me ages to do it and I have to use my tools slowly to get done what I can. I have nowhere near 15 years of experience of daily work and there's no way I'll ever have that either. What I've been shown by others or learned on here is all I know. I haven't seen your work or the way you work, I'm just intrigued as to how it is that you do it your way.


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## macmaw (Mar 5, 2007)

moosh said:


> So tell me this fella if you read my original post, there's on average 5 different layers from etched coat to clear coat and these are on all the panels of the main body and for your info under bonnets on a lot of cars these days are painted in a different fashion so unless you know this make up you would be hard pushed to come up with any averages.
> 
> Further more your theory of using inside of the doors to test, that makes no sense because in there is the same paint make up as the interior? If it had no clear it would not be shiney and wash off as modern paints are waterbased.


I don't need to know how thick the etch or the primer is, I'm not polishing that
The insides of my car are not clear coated & certainly do not wash off either


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## macmaw (Mar 5, 2007)

moosh said:


> ofcourse it matters, so your cutting microns off on say paint as thin as 90 microns? How do you know how much clear you have to play with?


By using a PTG which measures more than one coat, or by working out as already suggested Like we say, it's a guide only, but you seem to think you can tell how much clear coat is on a car by looking at it, you may be painter but unless you know the car's history, you could never tell how much clear coat it has.


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## -Raven- (Aug 26, 2010)

wee_green_mini said:


> What do you reckon the ratio of people burning through by not using a PTG is compared to people burning through who have used one is?


Ok then, what is it? 

I know heaps of pro's on here that have cut through the clear coat..... PTG didn't do **** to save them! :lol:


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## Bratwurst (Jan 23, 2009)

type[r]+ said:


> Ok then, what is it?
> 
> I know heaps of pro's on here that have cut through the clear coat..... PTG didn't do **** to save them! :lol:


Haha touche' :lol: - I don't know, but I'd wager 5 pounds :doublesho that the vast, vast majority of strike-through incidents happen when a PTG _isn't_ being used.

How many times do you think people who don't have a PTG yet take a rotary or DA to their car strike through and _don't _say on here?

I totally admit to not having any stats, but it stands to reason that if you have no way of knowing what you have to play with and go in blind, you're going to wreck something one day. If you go at it with a PTG (which at least gives you an insight of what's there before you touch it) then there is surely a smaller risk of strike through. Considerably smaller I think. It's common sense is it not?


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## moosh (May 8, 2011)

wee_green_mini said:


> Erm, no. I read your comments from the start and thought to myself that it goes against everything I was taught, that's why I've replied. I've not got anything personal against you, so please don't think that I do.
> 
> I just can't get my head around how you can say some of the things you do, that's all. You are saying "I have the knowledge not to need a PTG" which infers that you _know_ when you have lacquer to play with and when you don't. If there is this knowledge that means you don't need a PTG, then that same knowledge must be telling you that there is lacquer there and that you have enough of it there to do what you want to do at the time.
> 
> ...


Thank you for not taking my comments in an offensive way mate and yes i agree with your thinking and your need for having a PTG. 1 microns = 0.001 millimetres
You're intrigued to know how I know how much clear I have to play with and I would say as I have said qualification and experience.
Tell me how do you know how much clear you have to play with? - Who taught you and what is their training and qualification, not that I doubt their experience but I get the feeling my experience is being doubted because I don't use a PTG which goes against what pro detailers are teaching up and coming detailers. Safety comes first and I appreciate that.
The point I am getting at, say you get a reading of 200? What percentage of the 200 would you class as clear coat? Say for example we have a typical 3 stage paint system below (again you wont know this) but for example we divide the 200 by 3 = 67 so your clear coat is 67 and your average cut is 5-10microns? you never really cut that much off.
Russ from midlands car care recently did a course with KDS in wet sanding and I think the results from the depth of cut surprised a lot of people in that it doesn't cut as much as people thought it would. 
You take a reading and it gives you a reading of 200 so you machine the panel with various techniques pads compounds and finishing and then take another reading yes?
This reading says 195 ok? So you think you have removed 5? Paint expands with heat as does steel so how do you know you have only removed 5? Exactly 5? Well you don't you are relying on the PTG and guessing. You have a set routing and the time that it takes you to do each set you then finish that and check your cut? If you use the same technique each time on each set which you should if you are polishing the entire panel equally and at the end your reading is say 5. This will not be equal on all makes of paint as each is different so you can come up with an average that you cut so why do you then need a PTG if your skilled enough to only cut that small amount of paint material off?

We could then say yes but what about a scratch? Well im my eyes if you can catch a scratch with your nail you are not going to polish it out simple and if you are going to polish it out you can expect to be very nearly going through the clearcoat. The PTG can measure before and after but it can't tell you when to stop machining as you are about to breach the clearcoat and hit the basecoat. Doing scratches regardless of having a PTG you are pushing your luck and experience is what will save your bacon not a PTG. 
Another way to think of it is you are machining a car because it is swirled? How deep is a swirl? - You can't measure it but you can visually see it and see it disapear. Once you have removed the swirl do you tend to keep cutting? No you don't you then go on to finishing and refining which has little or no cut. - No need for a PTG.
Remembering 1 micron = 0.001mm that means you have to accurately measure to the same point with a setting out accuracy of 0.001mm the exact same spot to get the exact same reading.
Think of how many sqmm there is on the surface area of a panel say the bonnet? Then convert that in your head to how many microns sq/mm it is? Its collosal!! Say a panel area of 1.2m x 1.2m or 1200mm x 1200mm = 1440000mm2 I could continue but honestly it's pointless because the figures it spits out would need Stephen Hawkins to explain.
When painting a car the thickest parts with in the 5 stages is the primer and the clearcoat, I am now interested in getting a PTG to work out the depth of difference layers so I can return to the thread to explain the findings using a factory technique with factory approved paint so that it is approximately a good average. I don't however work in a bodyshop anymore I work as an engineering surveyor and civil engineer as I retrained but I keep up with the paintwork and panel work in my spare time as well as detailing. Detailing is where I would like to be with my spare time but I think the background from the motor trade has really helped in understanding machine polishing.

I hope this helps


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## -Raven- (Aug 26, 2010)

wee_green_mini said:


> Haha touche' :lol: - I don't know, but I'd wager 5 pounds :doublesho that the vast, vast majority of strike-through incidents happen when a PTG _isn't_ being used.


...by noobs who haven't learnt correct technique, or what to look out for. PTG will never stop someone using incorrect technique from burning through paint.



wee_green_mini said:


> How many times do you think people who don't have a PTG yet take a rotary or DA to their car strike through and _don't _say on here?


I will certainly say more noobs own up than pro's with PTG's who 'should know better' 



wee_green_mini said:


> I totally admit to not having any stats, but come on man, it stands to reason that if you have no way of knowing what you have to play with and go in blind, you're going to wreck something one day


I do agree with you, but just saying a PTG won't stop a rotary burning through paint. :thumb:

Great discussion anyway! :thumb:


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## -Raven- (Aug 26, 2010)

wee_green_mini said:


> It's common sense is it not?


This is the problem right here! The problem with common sense is it just ain't common! :lol:

If you're going to burn paint, PTG or not, you'll burn paint!


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## macmaw (Mar 5, 2007)

moosh said:


> Thank you for not taking my comments in an offensive way mate and yes i agree with your thinking and your need for having a PTG. 1 microns = 0.001 millimetres
> You're intrigued to know how I know how much clear I have to play with and I would say as I have said qualification and experience.
> Tell me how do you know how much clear you have to play with? - Who taught you and what is their training and qualification, not that I doubt their experience but I get the feeling my experience is being doubted because I don't use a PTG which goes against what pro detailers are teaching up and coming detailers. Safety comes first and I appreciate that.
> The point I am getting at, say you get a reading of 200? What percentage of the 200 would you class as clear coat? Say for example we have a typical 3 stage paint system below (again you wont know this) but for example we divide the 200 by 3 = 67 so your clear coat is 67 and your average cut is 5-10microns? you never really cut that much off.
> ...


I would agree with some of that, but not it all
From what I've seen, the clear coat will be thicker than the percentage you mention above.
If you have a look at the guides on here you will see this. 
You allow the paint to cool before taking your readings, & once again, there are PTGs out there which can measure clear coat.
Also we don't just go at it and go through the clear coat before the PTG tells us to stop, we stop regularly, try different combinations before settling on one which achieves the most correction with the least removal. 
The use of a laser pen ensures that you measure the exact same spot each time to assess what the cut is. 
If I took my car to you, how could you tell me how much clear coat I have on it?
Like I say, it's only the clear coat which we are working on


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## moosh (May 8, 2011)

macmaw said:


> By using a PTG which measures more than one coat, or by working out as already suggested Like we say, it's a guide only, but you seem to think you can tell how much clear coat is on a car by looking at it, you may be painter but unless you know the car's history, you could never tell how much clear coat it has.


You also cant tell how much clearcoat a car has nor can your PTG - Fact

but you seem to think you can tell how much clear coat is on a car by looking at it - Tell me where i wrote i have PTG eyes? :wall:

I can however spot by looking as can most pro detailers and painters can if a panel has been painted. There are always signs left.

What kind of car do you have? I dont know any cars that are left in basecoat, not one. If your car has a matt finish from factory inside the doors it will have had a mattening agent added to the clearcoat so it will still have a clearcoat and not be basecoat. - Fact

Waterbased paint will wash off for a certain time after painting but obviously after a period it will not wash off again a fact.

How deep is a swirl? How deep is a scratch? Answer you dont know nor does your PTG you polish until its gone and only then you will approximatley know how much you took off by cutting. You cant however put it back on nor can you ask it to tell you when to stop because you are going to breach the clearcoat.:buffer:


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## moosh (May 8, 2011)

macmaw said:


> I would agree with some of that, but not it all
> From what I've seen, the clear coat will be thicker than the percentage you mention above.
> If you have a look at the guides on here you will see this.
> You allow the paint to cool before taking your readings, & once again, there are PTGs out there which can measure clear coat.
> ...


I know how to polish a car i dont need an explaination of that :thumb:

If you took your car to me to tell you how much clear was on it i would be as well to just make it up because you wouldnt know either because as i keep saying your PTG doesnt know either. You say you get PTG's that can tell you? Would you buy one and how much do they cost?


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## Bratwurst (Jan 23, 2009)

We're going round in circles here.

Yes, that helps, and I am very impressed with your figures and calcs. Very clear to me and good too see on the page your thoughts. Spot-on. :thumb:
It all makes a lot of sense and I do understand how you've got to your conclusions.

But, you've just answered my questions I posed to you with questions.

Also, there is one huge thing you've omitted and is a big danger to us who machine polish... how can you tell (without a PTG) if a car's machined before to within a baw-hair of what lacquer it has left?

I know it's got it's errors and it's flaws, but it gives you an insight into a car's past and warns you of impending problems.

I went to 'polishing school' :lol: with Dave and Gordon (davekg and caledonia) in Glasgow a few years back. The method that was outlined several times before to you (regarding taking averages and measuring in shuts and the such) is how I get to have AN IDEA of how much lacquer there is or isn't there.

I was simply saying (and yes by questioning your method - but not maliciously, just in an intrigued way) that a PTG will, _at the very least_, give you an insight as to some sort of idea of paint and lacquer thickness - not using one means you don't even have an inkling (IMO)

I'm going to leave it at that, because I think we're on different wavelengths here :thumb:


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## moosh (May 8, 2011)

type[r]+ said:


> ...by noobs who haven't learnt correct technique, or what to look out for. PTG will never stop someone using incorrect technique from burning through paint.
> 
> I will certainly say more noobs own up than pro's with PTG's who 'should know better'
> 
> ...


This guy speaks the truth :thumb::argie:


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## moosh (May 8, 2011)

wee_green_mini said:


> We're going round in circles here.
> 
> Yes, that helps, and I am very impressed with your figures and calcs. Very clear to me and good too see on the page your thoughts. Spot-on. :thumb:
> It all makes a lot of sense and I do understand how you've got to your conclusions.
> ...


These guys would tell you the same that with experience comes knowledge, i read almost all of the pro threads on here and understand where they are coming from and agree in most parts and also learn lots and lots from them as well.

This sort of in depth topic needs a workshop a full day and plenty of tea to solve but like you say we are on different wavelengths here but the only difference is a PTG.

Your question is how do i tell how deep the clear is? Answer i dont its not of interest to me because i remove so little its not relevant.

The theory of measuring inside the doors sadly isnt always correct as there is less primer used and less paint used in there giving an in accurate reading as to the depth of the clear. I know you guys keep saying yes but we are not polishing the primers or basecoat but i am saying yes but these coats add to your over all depth and you dont know the individual depths of them so you can never work out the individual depth of clear and nor can i by eye.


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## Nanoman (Jan 17, 2009)

Just to throw my tuppence in...

I have two main uses for a PTG. The first is spotting high/low areas which could indicate previous machining to remove a scratch or a smart/respray repair (a good one that isn't noticed just by looking).

The second use is to check removal rates. 

^^^I don't think any of those things can be done without a PTG no matter how good you are.


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## Phat Pat (Mar 1, 2012)

To the Original Poster; personally, I would buy one if I were to consider polishing my car or other people’s cars regularly. I think ethically, it’s the right thing to do. The implications of burn through are not worth thinking about.

I realise that not everybody can afford £200+ for a device that will only be used from time to time, but if your paint is of an old type on a cherished vehicle I don’t think I would take a polisher anywhere near it without one.


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## macmaw (Mar 5, 2007)

moosh said:


> I know how to polish a car i dont need an explaination of that :thumb:
> 
> If you took your car to me to tell you how much clear was on it i would be as well to just make it up because you wouldnt know either because as i keep saying your PTG doesnt know either. You say you get PTG's that can tell you? Would you buy one and how much do they cost?


No, I wouldn't buy one but I was pro then I would, but you keep suggesting that a PTG does not exist which can measure clear coat.
There are plenty that do.


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## moosh (May 8, 2011)

macmaw said:


> No, I wouldn't buy one but I was pro then I would, but you keep suggesting that a PTG does not exist which can measure clear coat.
> There are plenty that do.


I havent suggested there isnt a PTG in the world that cant do it, im suggesting the one that you personally own and probably a large % of DW pro/non Pro machine men/women's PTG's cant measure clearcoat? Am i correct?

Please link me to one that does for my info?

Also what make of car do you own that has no clearcoat in the door checks also for my info?

Finally i'll ask you again how do you know how deep your clearcoat is?

Ive been badgered to answer your questions so please answer the above or drop it :thumb:


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## XRDAN (Feb 28, 2012)

moosh said:


> Finally i'll ask you again how do you know how deep your clearcoat is?


nice simple question:thumb:


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## moosh (May 8, 2011)

Macmaw

Just a quick simple google search for me.

http://www.paintdetective.com/why_use_a_paint_gauge.html - No where does this state it can measure specific depths.

http://www.defelsko.com/application...aint-detailing.htm#ThreeMeasurementPrinciples - Below statement taken from this link.
What does a paint thickness gage measure?
Magnetic and Eddy Current
Paint thickness gauges simply measure or distance (height or gap) between the probe tip and the base metal. They make no distinction between the layers that make up that distance. Their thickness calculation includes the thickness of all layers (primer, base-color and clear coats), any repainted material, filler material, dirt, etc. Unless a measurement is taken before and after each layer has been applied, the user must estimate the thickness of each layer.
It then goes on to say this - which I think is clearly a sales pitch!
What is clear coat?
The clear coat is polyethylene paint without color pigmentation. Thickness usually ranges between 1.5 - 2.0 mils (35 - 50 microns). It is the final original equipment manufacturers coating applied to a vehicle to protect the (base) color coat from a hostile environment while providing both depth and a durable, glossy appearance. It is easily scratched and, once compromised, requires re-painting, as the base color has no shine or brilliance. Also, the clear coat provides UVR protection for the colored paint layer. 
Car manufacturers now specify that the paint thickness be measured before and after any wet sanding or buffing. Measurements should be taken regularly since it is virtually impossible to see how much paint is being removed during the buffing process. Using a paint thickness gauge gives a professional detailer credibility and also acts as an insurance against 'break-though' of a clear coat, which would entail a re-paint.
Clearcoat is approx. 35 - 50 microns (according to the site above) so on average most threads I read on here no one cuts more than 10 microns so I feel safe knowing that I certainly don't cut anywhere near 35-50.
I have said previously that a PTG was originally brought to market for car garages to check panels for repairs and paintwork for warrenty claims and both site suggest that this is what they are for and I agree with that.
Both mention that they cannot measure the depth of clearcoat but they can how ever give you a gauge on what you are cutting and I don't disagree with that either.


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## macmaw (Mar 5, 2007)

moosh said:


> I havent suggested there isnt a PTG in the world that cant do it, im suggesting the one that you personally own and probably a large % of DW pro/non Pro machine men/women's PTG's cant measure clearcoat? Am i correct?
> 
> Please link me to one that does for my info?
> 
> ...


You can see one in use in this thread 
http://www.detailingworld.co.uk/forum/showthread.php?t=262401

Drop what?

I think a lot of the posts have been lost in translation & perception, I thought we were just having a healthy debate :thumb:

I've already answered how I get an idea of my clear coat thickness, which I have been told is a good way of gauging it for those of us who do not have the luxury of a composite PTG - for guidance only.

Nobody ever knows for sure, as all PTGs are for guides only.
You have stated that through experience "you know what you've got"

My car is a 2003 BMW 530i Sport for info.

I won't doubt what you say about the painting side of things, but I can't think why a car manufacturer would go to the trouble of using a separate matting agent on the insides of the doors , boot, bonnet etc, why not just leave it clear coated?
That's not having a go at you, that's just me wondering about it - that's all


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## XRDAN (Feb 28, 2012)

so you can use a PTG before and during cutting to tell you how much clear paint you are taking away, for this purpose I can see the PTG as a usefull tool. how far you can go is still based in an assumption as you will never get a definate reading of just clearcoat depth. If you inspect the panel you can be 99% sure on weather it has the OEM finish or not and take it from there...

thats just my thoughts on the topic based on the little knoledge of painwork i have:thumb:


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## XRDAN (Feb 28, 2012)

macmaw said:


> You can see one in use in this thread
> http://www.detailingworld.co.uk/forum/showthread.php?t=262401
> 
> I think a lot of the posts have been lost in translation & perception, I thought we were just having a healthy debate :thumb:
> ...


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## maersk (Sep 6, 2007)

A very interesting debate, with lots of generally well informed information but some statements concern me.......

'What kind of car do you have? I dont know any cars that are left in basecoat, not one. If your car has a matt finish from factory inside the doors it will have had a mattening agent added to the clearcoat so it will still have a clearcoat and not be basecoat. - Fact'



Audi/VW are basecoat (no lacquer) under the bonnet area and in the boot - unless it is an S-line bult in Neckarsulm, where the under bonnet areas are lacquered as they are painted by hand. Peugeot are also not lacquered under the bonnet/boot area.

Water based paint systems do not wash off, even at the factory when wet as they are electrostatically applied and the EXCESS is washed off in a water tank before being baked. This matt colour is then coated with clear lacquer, which to save cost is only applied to the 'cosmetic areas' of the vehicle. It too is water based. Many recent new models only recieve the phosphate dip and electrostatic primer from the immersive bath to 'hidden areas' such as the inner boot areas to save money - no colour basecoat is applied. The vehicle is then baked for a second time to complete the paint system. 

Does this mean our cars are biscuits?


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## moosh (May 8, 2011)

maersk said:


> A very interesting debate, with lots of generally well informed information but some statements concern me.......
> 
> 'What kind of car do you have? I dont know any cars that are left in basecoat, not one. If your car has a matt finish from factory inside the doors it will have had a mattening agent added to the clearcoat so it will still have a clearcoat and not be basecoat. - Fact'
> 
> ...


What kind of biscuit did you have in mind?? Would a PTG work on it?

I have an S Line A3 he's painted under the bonnet and boot.

The chap was saying the inside of his door were not laquered, would you agree that is incorrect? Hence I asked what kind of car he has.

Some manufacturers now leave cars in grey/beige primer in the engine bay eek! Some use tinted primers and these are not waterbased some paint them so don't.


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## maersk (Sep 6, 2007)

The door shuts are of course lacquered.
Your A3 S-Line was almost certainly built at Neckarsulm (90% of all S-Line models were) as 'proven'by the lacquered boot and under bonnet area - it is the classic give-away with these models. If it is basecoat colour only then the body was completed at another Audi plant. The Neckarsulm paint line (until late last year) was one of the oldest in the Audi line up and the lacquer stages were still hand applied, hence the bay and boot coverage (looks nicer IMHO) It has now been upgraded and is predominantly used for R8 and A8 and special colour requests. Quite a few tinted and coloured primer and undercoats now (thankfully, Ford's white primer beneath solid Black was a stonechip nightmare) Porsche use ten different undercoats to match the basecoat colour..............
That is after galvanising, etch primer, phosphate coating.........
Sadly Audi now only galvanise the lower half of the bodies (from 2008 model year) 
It's true, they don't make em like they used to.............mind you they don't fall apart at three years old either........... ahhhh 1973, that was a year....... primer dip and a splash of cellulose solid to cover (if you were lucky). Mind you the whole thing weighed about 5/600 kilos

A chocolate HobNob....................

PDG won't work on them.

Whilst on the subject of PDG, I fail to understand why they are still so expensive. OK supply and demand etc. but there are other equally sophisticated bits of electrickery out there with equally 'small' demand which manage to reduce in price annually................. :devil:

Looks for entrepreneurial gap in the market...............


What do you think Duncan? Alan?


I'm ooot! :lol:

With regret, you're fired! :doublesho




Tumshie.


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## The Cueball (Feb 8, 2007)

Maybe some food for thought…. I thought I would post this up since it only happened last night…

I took my mates Jeep down to a local pro, as there was damage that I have never seen before on the clear coat… I thought this “crazing” was the start of failure, but wanted a professional to have a look…

He came out, took one look and confirmed what I thought… and then we had a closer look at the paint… with the “cheaper” reader…

Along one side of the Jeep:

97,98,100,97,100,102,…..500,560,100,400,70,90,500,510…

:doublesho

No way on earth you would have known that, without checking….

OK.. gives you a clue that there has been some repairs…

The more expensive reader came out to play…

And what it showed was that on most of the paint, on the side of the Jeep, it could only get reading of the base and colour sections…. It was not picking up a reading on the clear coat….

Now various reasons for this, but why the reader wasn’t showing it, was because the clear was less than 13 microns!!!!!!!

Now I don’t expect people to be honest with this…. But how many people would have either not taken readings, or thought, well I have loads of clear to play with (the door jams were coming in about 50)… and carried on with a polish?!?!?!?!

A real eye opener for me….

Oh, and thanks to Gordon for his time and use of equipment…

:thumb:


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## macmaw (Mar 5, 2007)

My mistake about the insides of the doors, they are of course clear coated, I meant to say under the bonnet & the boot etc but included doors for some reason! 
I can only blame my own stupididty for that


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## waxy (Feb 27, 2006)

moosh said:


> I know how to use a machine polisher and under stand my products and pads and the paint I am polishing, I was a painter to trade and we were taught refinishing in college as part of our course. PDGs were never used and still not used in bodyshops when polishing they are mainly used in warrenty work to check if panels have been painted previously.when polishing a car its all about (imo) properly inspecting the paint work prior to polishing, it really is not that scientific. Panel expands and contracts when heated and cooled so PTGs can be inaccurate but I don't disagree with people who use them.


I think many people would agree that 90% of Bodyshops do not,and can not refinish their own work to an acceptable standard, not implying that you fall into this category,but it is seen all too often.Can you explain exactly what it was that you were taught at college that enables you to not need the safety net of any PTG when polishing paint? You say that IYO,polishing is all about properly inspecting the paintwork prior to polishing,so with this visual inspection only,would you then be able to tell me,for example how much clear is left on my 27 year old Ford Escort?,would this visual inspection provide you with enough information to be able to determine if you could polish out RDS on said paintwork, without striking through to the base coat,and also to not leave insufficient material that would lead to premature failure of the clear coat later on? Would the visual inspection enable you to be able to determine if you could remove holograms and RDS from paintwork that had been previously over polished by machine,and left with less than half of it's factory applied clear coat thickness?


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## maersk (Sep 6, 2007)

For me RDS should be filled with lacquer and wet sanded followed by a shallow polish..........I rarely polish RDS, unless your RDS are not my RDS, if you see what I mean.....


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## moosh (May 8, 2011)

waxy said:


> I think many people would agree that 90% of Bodyshops do not,and can not refinish their own work to an acceptable standard, not implying that you fall into this category,but it is seen all too often.Can you explain exactly what it was that you were taught at college that enables you to not need the safety net of any PTG when polishing paint? You say that IYO,polishing is all about properly inspecting the paintwork prior to polishing,so with this visual inspection only,would you then be able to tell me,for example how much clear is left on my 27 year old Ford Escort?,would this visual inspection provide you with enough information to be able to determine if you could polish out RDS on said paintwork, without striking through to the base coat,and also to not leave insufficient material that would lead to premature failure of the clear coat later on? Would the visual inspection enable you to be able to determine if you could remove holograms and RDS from paintwork that had been previously over polished by machine,and left with less than half of it's factory applied clear coat thickness?


I love a have a go hero :thumb:I agree bodyshops are not so great on finishing hence why I left the trade full time 8 years ago and retrained at university so now I'm an engineer and a keen detailer with the best of both worlds.

I have the training in paint with the qualification to go with it and thankfully for DW many many nice guys sharing tips I have learnt a lot.

Sadly I got bored reading the rest of your post because I remember the last time we crossed path you were an aresol then as well. :wave:


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## moosh (May 8, 2011)

maersk said:


> For me RDS should be filled with lacquer and wet sanded followed by a shallow polish..........I rarely polish RDS, unless your RDS are not my RDS, if you see what I mean.....


I'm the same :thumb: if filling and wet sanding is not going to turn out well I wouldn't try and repair it I would paint the panel.


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## -Raven- (Aug 26, 2010)

waxy said:


> I think many people would agree that 90% of Bodyshops do not,and can not refinish their own work to an acceptable standard,


They could, but it's a huge waste of man hours to them for no financial gain what so ever.


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## macmaw (Mar 5, 2007)

type[r]+ said:


> They could, but it's a huge waste of man hours to them for no financial gain what so ever.


I would agree with that, the "best" bodyshops up my way are also famously expensive - so they probably take the extra time & time is money


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## Bratwurst (Jan 23, 2009)

moosh said:


> I love a have a go hero :thumb:I agree bodyshops are not so great on finishing hence why I left the trade full time 8 years ago and retrained at university so now I'm an engineer and a keen detailer with the best of both worlds.
> 
> I have the training in paint with the qualification to go with it and thankfully for DW many many nice guys sharing tips I have learnt a lot.
> 
> Sadly I got bored reading the rest of your post because I remember the last time we crossed path you were an aresol then as well. :wave:


You got bored or don't have any answers?

Or should that be, you got bored because you have run out of questions to ask instead of providing answers?

That was a harsh post, no need for it when all he was doing was asking you a few questions.

I left the discussion earlier because I felt we were just going over old ground over and over again... but it's actually not the case, you are the one who's not answering some questions and being rather vague about it all causing folk to repeat themselves to you.

I read your posts with interest. While I disagreed with some of your methods, I at least sat and thought about it. Also, you said that the use of a PTG is inherently flawed. Not your exact words, but this is what you have been saying. I do agree that it SEEMS to be flawed in some ways (ie measuring exact lacquer thickness using shuts etc). You've no-doubt opened a few eyes with regard to PTG's there. However, there can surely be no argument against the fact that a PTG is an invaluable tool when working out removal rates?

Seems to me that whenever anyone challenges your methods (which again seem to be no more than just looking at the paint and guessing) you have limited answers.

...and now you start calling a guy an ar5ehole.

Poor show.

I can see your probably fed up being questioned. I was already fed up replying and getting nowhere with you, but I felt I had to come back in after reading your previous post.


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## moosh (May 8, 2011)

wee_green_mini said:


> You got bored or don't have any answers?
> 
> Or should that be, you got bored because you have run out of questions to ask instead of providing answers?
> 
> ...


He's been reading the thread all through and thanking people and decided when the thread was improving to have a go, he also did this on another thread i was trying to help on hence i was rude. I was bored to be honest as i am sure you have said you were fed up of replying, All i kept asking was how do you measure your clear, i.e the depths of materials that make up the over all depth of the painted surface.

I feel i had answered all valid questions with maybe an explaination rather than an answer but the big question that kept coming back was - How do i measure clear? I dont experience tells me. I asked how do you guys with PTG's do it? - You cant specifically. BUT the PTG is handy to measure removal rates and i agree. It was mentioned it was found handy in spotting a previous repair and blend on a panel - thats what is is designed to do which i stated early on. I never cut that much from the clear and as i have said RDS are polished with caution and i would advise they be painted rather than removing depth of the clear as that is dangerous regardless if you have a PTG or not. I polish out swirls and minor scratches, i asked how deep are these and no one could answer that not even me but i can say they are not very deep and i am sure you will agree.

I think the thread has been good thus far and you say i may have opened a few eyes and i have also had my eyes open, I didnt mind being challenged when it was valid but there were many trying for the sake of it imo.

What do you personally feel i havent answered?


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## Bratwurst (Jan 23, 2009)

Ok. Thanks. I had no idea about another thread. You can see how I took exception to it?

The thread has been good, totally agree, it's been excellent reading back through it.

You certainly have opened eyes with the depth calculation and also pointing out the missing info (or amount of positive spin maybe) on the PTG sites.

A wee question - not to you moosh, to folk who use a paint detective PTG - do you feel now like we have all bought a thing which isn't all it's cracked up to be with regard to calculating lacquer depth?

I suppose my main question to you is this; you said you don't use a PTG, but your years of experience in the trade have given you the skills to do the machine polishing you do and that you've not come a cropper, as it were, so what is it that you're looking at then when you're machining a car - Is there some tell-tale sign you're seeing that is giving you an idea of the amount of clear-coat you have to play with?


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## moosh (May 8, 2011)

macmaw said:


> I would agree with that, the "best" bodyshops up my way are also famously expensive - so they probably take the extra time & time is money


Most bodyshops run on bonus schemes and rely on clients not being to bothered about thier paint finish. If they knock out 10 cars that have been poorly polished and only get one come back then bonus wise they are quids in. Sad but true thats the reason i left the trade i was customer focused and not pocket focused, i didnt mind not making bonus as the cars were going out better than factory but i was scunnered with the people i was working with so i got out of it. The insurance companies are to blame as they wont pay the rates to repair things properly.

For example a new wing and bumper is required, the panel beater will get 1.5 hrs to do the job and the painter will get say 3.5. This time is supposed to cover removal of the old parts, strip the door for a blend and then once it is painted re build it. In some bodyshops it would take you 1.5 to find the keys to the car and get it in the workshop to begin work. So to make it work better for the panel beater they will share hours so they have 2.5hrs each, this wouldnt cover either of them so the point i am getting at if these guys are dammed before they even start its hard to spend any time on the finishing touches which is a shame for the trade.


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## moosh (May 8, 2011)

wee_green_mini said:


> Ok. Thanks. I had no idea about another thread. You can see how I took exception to it?
> 
> The thread has been good, totally agree, it's been excellent reading back through it.
> 
> ...


Thats the thing mate until getting involved in the detailing world and various forums its never been something that concerns be, and i know people are going to rare up at that comment but its not something thats ever been a concern, when we were at college we had shells that we painted and polished and were shown how to polish through the clear and how to use a machine etc similar to how the Pro guys who do lessons do. We were never shown or given a PTG and i am sure they were about when i was at college.

When i do an inspection of a painted surface, i do the visual now that takes a long time. On RDS's i will make a mental note of these but not do any work on them. I then begin polishing and what and where i look is mostly behind the polisher to see how the refining is coming along and return to areas which require it but i dont concentrate at this stage on RDS. I machine the entire car to remove all defects bar RDS's, whilst machining i will polish then finish each panel then move to the next.

Next stage that i do is wash the whole car again to remove and dust and excess residue that may have been missed, i then dry with a new towel and using a compressor removing the trapped waters. I also dry door checks and grills so that the car is almost ready for lsp.

I then return and inspect the car again going round it and marking with a small piece of blue masking the RDS and then take it from there. Because each and ever RDS is different it would be hard to explain how i would tackle them but again will be exactly how a pro does it in a round about fashion as were all different.


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## Bratwurst (Jan 23, 2009)

So you polish anyway as long as you're sure there's clear there with no previous damage?

If there's clear there and undamaged, that's you good to go?


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## macmaw (Mar 5, 2007)

wee_green_mini said:


> Ok.
> 
> A wee question - not to you moosh, to folk who use a paint detective PTG - do you feel now like we have all bought a thing which isn't all it's cracked up to be with regard to calculating lacquer depth?


I don't personally, as I know it's only really good as a guide for removal rates, unlike the Positector, which can measure clear coat alone.

But also, when you start on your car for the first time, the paint detective or any other similar device can still give you over all readings as a base line - albeit these are all in one readings - but you can still gauge a rough idea if your paint is original or not.
As moosh says, if a panel has been painted for example, & it's unsually thick readings, we cannot assume there is plenty clear coat on that panel because of that & because we cannot measure clear coat with our standard PTGs, again that's where pro tools like the Positector come in, & I apologise to moosh if he feels a bit picked on here, as a few of the posts have gone off on a tangent. But I still don't know how he can gauge it without one!  
I'm afraid that for us non pros, that's all we can go by.
It still gives me the peace of mind to know how much I am removing, it's also a good learning aid for trying out different combinations to try & get maximum correction with minimal removal.


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## Nanoman (Jan 17, 2009)

wee_green_mini said:


> A wee question - not to you moosh, to folk who use a paint detective PTG - do you feel now like we have all bought a thing which isn't all it's cracked up to be with regard to calculating lacquer depth?


Anyone who does a quick check will find that a PTG/PDG (thickness/Depth who cares) such as the PD8 does not tell you specifically how much clear you have...

A question I asked which I don't think had been answered was directed at those who said something along the lines of "I've done machining without a PTG and never had a problem". My question was 'how do you know?' i.e. how do you know you've never had a problem? *How do you know you didn't rip through an uneccessary amount of clear? *How do you know what your removal rate is?

For me machine correction is the art of removing paint defects with the absolute minimum clear removal. For example some of the best results by the best pros on here aren't 'perfect'. Some clearly state "we couldn't remove this defect without risking permenant damage to the paint system and without a respray". For me this is especially important when working on rare/classic cars where respray world ruin the 'original'.

Removing defects without worrying about how much clearcoat you are removing is butchery.


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## The Cueball (Feb 8, 2007)

^^ anyone can polish a car into a bawhair of life left.... doesn't mean it's right or they have done the correct thing...

I agree... it's an art to get the right finish with the least removal...

Are PDG full proof, no, I don't think they ever will be, do they help me, factual or placebo, yes... so I'll keep using them, and keep trying to learn about paints etc etc as well

:thumb:


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## waxy (Feb 27, 2006)

moosh said:


> I love a have a go hero :thumb:I agree bodyshops are not so great on finishing hence why I left the trade full time 8 years ago and retrained at university so now I'm an engineer and a keen detailer with the best of both worlds.
> 
> I have the training in paint with the qualification to go with it and thankfully for DW many many nice guys sharing tips I have learnt a lot.
> 
> Sadly I got bored reading the rest of your post because I remember the last time we crossed path you were an aresol then as well. :wave:


Have a go hero  as the saying goes,attack is the best form of defence.Several times in this thread you have responded to members questions, with questions of your own,no answers.Was it boredom,or lack of knowledge that prevented you from reading my post fully.I recall the last time in your view ''we crossed path'',you didn't have any answers then either.All i did was ask several questions,which i thought would be valid to this thread,so does that make me an aresol? or does it make me an aresol if i ask questions that you are unable to answer? your comments have taken the OP thread off topic,but i don't think you care about that.I'll tell you one thing though,you don't know me,and i don't know you,but you will not see me resort to name calling when i have nothing to say.


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## waxy (Feb 27, 2006)

moosh said:


> He's been reading the thread all through and thanking people and decided when the thread was improving to have a go, he also did this on another thread i was trying to help on hence i was rude. I was bored to be honest as i am sure you have said you were fed up of replying, All i kept asking was how do you measure your clear, i.e the depths of materials that make up the over all depth of the painted surface.
> 
> I feel i had answered all valid questions with maybe an explaination rather than an answer but the big question that kept coming back was - How do i measure clear? I dont experience tells me. I asked how do you guys with PTG's do it? - You cant specifically. BUT the PTG is handy to measure removal rates and i agree. It was mentioned it was found handy in spotting a previous repair and blend on a panel - thats what is is designed to do which i stated early on. I never cut that much from the clear and as i have said RDS are polished with caution and i would advise they be painted rather than removing depth of the clear as that is dangerous regardless if you have a PTG or not. I polish out swirls and minor scratches, i asked how deep are these and no one could answer that not even me but i can say they are not very deep and i am sure you will agree.
> 
> ...


Where in this thread have i ''had a go'' is your definition of ''having a go'' at you,someone who asks valid questions that you are unable to answer? as for thanking people in this thread,yes i have thanked people in this thread when i have considered their contribution to be valuable,that's what the thanks button is their for  i really don't know what you are on about.

''He did this on another thread'' did what? expressed an opinion,disagreed with you,yes,so you don't like that,well it's called freedom of speech,are these your reasons for being rude and calling me an ''aersol''? i'll wait and see if you become bored again during this thread,possibly when you are unable to provide answers to questions again.I was not even going to bother commenting,but seeing as you have called me an ''aersol'' and tried to suggest that i have ''had a go'' at you,i felt i had no choice.No doubt you will have to have the last word,after all you have turned this thread into being about you and your opinions,i will not reply again,your ego however,will dictate that you do.


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## moosh (May 8, 2011)

This is a great thread and will surprise you maybe, I use the same techniques as I would expect as Kelly is obviously bodyshop trained in painting as well.

http://www.detailingworld.co.uk/forum/showthread.php?t=244507


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