# Removing orange peel with wet sanding



## Nikon1149 (Oct 1, 2009)

During my now frequent and lengthly trawls through the amazing labyrinth of information that is the DW archives I came across mentioning of a detailer who does full body paint wet sanding correction and was immensely impressed by his mirror like finishes.

Now, i'm certainly getting ahead of myself here as I have yet to even take my newly purchased DA to my paint, but I know that once i've revived my paint as far as the DA will take it i'll be looking to go to the next level.

Well my question is are there any guides on exactly how to do the wet sanding thing to rid the finish of the orange peel effect (which my car has quite a lot of) and get that mirror finish (my car is black ).

It's something for the (maybe not-too distant) future. Also, seeing as DA's are also designed for sanding jobs, could they be used for wet sanding down body panels, and also to refurbish alloys (another item on my car-to-do-list)?


----------



## Tiggs (Feb 28, 2007)

Have a look in the DW TV section there a good bit on wet sanding there with the mirca pads.




:thumb:


----------



## Guest (Nov 9, 2009)

Simple innit, sand till there is no orange peel left, but stop if you are gonna remove too much lacquer (or topcoat) in the process.


----------



## Rickyboy (Oct 14, 2008)

I'm interested in trying this too as my 197 is quite bad for orange peel.

I'm guessing a PDG is an absolute must for a job like this?


----------



## Tiggs (Feb 28, 2007)

> Simple innit


How about what grade grit to start-finish with, paint thickness of paint to start with..................'simple innit' :doublesho


----------



## Guest (Nov 9, 2009)

doesn't matter, "sand *till* there is no orange peel left" implies use of correct grade


----------



## Paintguy (Oct 31, 2005)

Nikon1149 said:


> . Also, seeing as DA's are also designed for sanding jobs, could they be used for wet sanding down body panels, and also to refurbish alloys (another item on my car-to-do-list)?


Yes, they certainly could, although I prefer to use an air-powered machine for wet sanding, as I've never really liked mixing water and electrickery 

And as said, removing OP is an extremely easy task, but unfortunately it's even easier to get it wrong and remove too much paint/clearcoat if you don't know what you are doing. Best left to those with plenty of experience, or those with a paint thickness gauge


----------



## Guest (Nov 9, 2009)

Rickyboy said:


> I'm guessing a PDG is an absolute must for a job like this?


Yes (actually that's a bit hypocritical, I didn't use a PTG) and even then you are not guaranteed to be free from striking through. A bit of common sense goes a long way though. I've wetsanded plenty of panels on my car now with no problem.

When I let my friend have a go and he started to sand the bit where the lacquer had already come off (from a spraying defect), I can sort of understand how people manage to bugger it up


----------



## KennyC (Aug 11, 2008)

Don't forget that if you remove all orange peel your clearcoat will be very thin afterwards, meaning that you may not be able to remove and RDS/ key marks etc in the future. The M3 that was posted on here that had a lot of clearcoat to play with so it was safe(ish) to wetsand.


----------



## KennyC (Aug 11, 2008)

Tiggs said:


> How about what grade grit to start-finish with, paint thickness of paint to start with..................'simple innit' :doublesho


To answer those questions how long is a piece of string? All paints are different and you will just have to start with the least aggressive method, skip 3000 and 4000 grit though.


----------



## dholdi (Oct 1, 2008)

This is all assuming the op is in the clearcoat and not the base.


----------



## Tiggs (Feb 28, 2007)

> Quote:
> Originally Posted by Tiggs
> How about what grade grit to start-finish with, paint thickness of paint to start with..................'simple innit'
> 
> To answer those questions how lond is a piece of string? All paints are different and you will just have to start with the least aggressive method, skip 3000 and 4000 grit though.


My point exactly, you cant just say its 'simple'. take a look at the studio section with the 'E92 M3' entry, do think this guy taking this many precations because it sells his service...i think not.


----------



## Guest (Nov 9, 2009)

dholdi said:


> This is all assuming the op is in the clearcoat and not the base.


Speak for yourself



G220 said:


> (or topcoat)


----------



## KennyC (Aug 11, 2008)

Tiggs said:


> My point exactly, you cant just say its 'simple'. take a look at the studio section with the 'E92 M3' entry, do think this guy taking this many precations because it sells his service...i think not.


Sorry, I was trying to back you up with my post and not start and arguement :thumb: Removing op from a factory finish without the proper insurance is madness imho


----------



## -ROM- (Feb 23, 2007)

Sanding to remove normal OP found in most modern cars, is not a good idea! You may do what you think is a good job without striking through but that much removal could seriously reduce the life span of the clear coat and cause premature failure.


----------



## Guest (Nov 9, 2009)

Tiggs said:


> My point exactly, you cant just say its 'simple'. take a look at the studio section with the 'E92 M3' entry, do think this guy taking this many precations because it sells his service...i think not.


If you are doing it to other people's cars then perhaps, if you are doing it to your own then it is your own responsibility if any ramifications occur and you will have to live with it. If you aren't comfortable with facing ramifications that you can't pay to rectify then get a professional to do it who is insured.

Personally I think it's silly to remove orange peel from a new factory paint job unless you have a lot of money or don't plan on keeping the car for a long time. But, it's each to their own. I did a few panels on my car either because they need a respray in not too long or have other defects (peeling lacquer). If the paintwork was in better shape I wouldn't bother.


----------



## Nikon1149 (Oct 1, 2009)

The detailer I referred to in the original post demonstrated removal of OP on a few cars and it seemed an average amount of clearcoat to remove was about 10nm, which seems very acceptable to me...

Someone quoted "all assuming the orange peel is in the clear coat not the base". I never knew this was even a possibility. Shame, maybe that crystal clear mirror finish will be ever elusive and just not realistic eh.

Surprising amount of people seem to think this is not a safe/worth while procedure... maybe i'll just lessen the orange peel effect with a good glaze and LSP :thumb:


----------



## dholdi (Oct 1, 2008)

G220 said:


> Speak for yourself


?



G220 said:


> Simple innit, sand till there is no orange peel left, but stop if you are gonna remove too much lacquer (or topcoat) in the process.


I understand what you are saying but this doesnt explain that the orangepeel could be in the base coat, in which case there would be no point in even starting to sand the topcoat ( lacquer )


----------



## Paintguy (Oct 31, 2005)

rmorgan84 said:


> Sanding to remove normal OP found in most modern cars, is not a good idea! You may do what you think is a good job without striking through but that much removal could seriously reduce the life span of the clear coat and cause premature failure.


Please don't take this the wrong way as I'm asking out of curiosity rather than trying to be argumentative, but have you got any proof to back up what you're saying? I see statements like this bandied around quite a bit, but have yet to see anyone back them up with cold hard facts. Sure, it goes without saying that the more 'paint' you remove (be it clearcoat, gloss topcoat, whatever), the less depth you will have available for possible future correction, but why should removing 15-20% of the original topcoats depth automatically prove catastrophic?

Cheers


----------



## Paintguy (Oct 31, 2005)

dholdi said:


> I understand what you are saying but this doesnt explain that the orangepeel could be in the base coat, in which case there would be no point in even starting to sand the topcoat ( lacquer )


But basecoat OP can only be seen relatively close up, and will have minimal effect on the gloss level of the top coat, and won't bee seen at all in the reflection type shots so prevalent around here once the resulting topcoat OP is removed


----------



## dholdi (Oct 1, 2008)

Yep, I'm not trying to cause arguments, just pointing out that you need to be sure the op is in the topcoat before considering wetsanding, otherwise its pointless.


----------



## charlie_51 (Sep 19, 2008)

get some 3000 grade megs on a megs sanding block. these sanding marks can be removed by a single pass of intensive polish on a megs polishing pad very quickly unless your detailing very very hard paint but even then the paper itself will be less effective.


there is a significant jump in agressiveness between 2500 grade and 3000 grade. thats from experience on my jaguar bumpers!


----------



## dooka (Aug 1, 2006)

Everyone is banging on about wet sanding, what about dry sanding, this is the route that I'm starting to take..


----------



## Paintguy (Oct 31, 2005)

qstix said:


> Everyone is banging on about wet sanding, what about dry sanding, this is the route that I'm starting to take..


I'd love to know how you get on. Not very well I'd guess.

Whilst dry sanding is great for bodyshop type work, the grades required for detailing are so super fine that they'll get clogged up very quickly with sanding residue. Even coarser grades like P1200 need a stearate lubricant built into them to help them shed this residue, so when you move to something like P3000 for example you can expect to get through one hell of a lot of paper. Using these super fine grades wet is a much better idea, as the water helps to wash away the residue, which not only makes sanding more effective, it helps the abrasive to last longer, and reduced clogging significantly reduces the risk of deeper random scratches being imparted by the 'clumped' residue.


----------



## qwertyuiop (Jul 3, 2009)

OP is caused by applying paint which is too thick,were as a professional skilled painter will apply 3 or more fairly thin coats,the machine at the factory will apply as much paint as possible in the least number of coats.Clearcoat isn't as easy to apply thickly,due to its almost water like consistancy (try sprayin water, lol).As fer dry sanding, I'll go with the above post, a bit of washing up liquid in the water helps act as a lubricator.


----------



## Dave KG (Feb 23, 2006)

Paintguy said:


> Please don't take this the wrong way as I'm asking out of curiosity rather than trying to be argumentative, but have you got any proof to back up what you're saying? I see statements like this bandied around quite a bit, but have yet to see anyone back them up with cold hard facts. Sure, it goes without saying that the more 'paint' you remove (be it clearcoat, gloss topcoat, whatever), the less depth you will have available for possible future correction, but why should removing 15-20% of the original topcoats depth automatically prove catastrophic?
> 
> Cheers


There have been papers published about this, not sure if you need an Athens account to be able to read the journal they are in however.

However the basic jist of the presented theory... The clearcoat essentially relies on its thickness to protect the interface layer(s) between clearcoat and colour coat. Now these layers are not hard and fast but there will be a degree of an interface. This interface is, according to these reviews, susceptible to UV damage which I can happily take as being true. If you reduce the thickness of the clearcoat you reduce is UV protection through absorption which could increase the level of UV at the interface and promote premature failure. If I can dig out the papers I will PM you the details but if they need an Athens login you wont be able to download or read anything more than the abstracts. Very interesting however and certainly make you think twice about removing large amounts of clearcoat. We've all seen clearcoat failure through peeling and these reviews suggest this is down to UV damage at the interface layer and reducing the clearcoat's essentially self protection can accelerate this process.

Let us also not forget the rather more simple physical aspects of removing large amounts of clearcoat when it comes to future polishing - fine and fair enough, stunning results from OP removal, mirror like shine. But if its at the cost of 10 - 15um as some are suggesting, is it all really worth it? Depends on the circumstance - but I will never do it to my car, as its a daily hack that works for its living. I could send it to a perfect finish, leave it in the work car park and have someone brush along it such that they inflict deep swirls - spoiling my finish and if the paint is much thinner, my scope for removal is dramatically reduced. Its horses for courses, but as I always say - removing paint defects is all good and well, we could sand and polish until all the marks are gone. But one must also be very aware of the effects on the car and its paint, and how this affects the paint from the above discussion as well as future scope for polishing and refinishing.


----------



## Paintguy (Oct 31, 2005)

qwertyuiop said:


> ,were as a professional skilled painter will apply 3 or more fairly thin coats,


That doesn't say much for me then lol, I haven't applied 3 coats of clear for years!  Modern UHS clears are designed to do the job in one coat, although sometimes a very thin 'grip' coat is applied first, and given a few seconds to flash before applying the full coat.

I tend to put a bit more on flat panels like roofs and bonnets (although really I shouldn't), to allow for us to flat & polish out any dirt. They get a decent half coat first, then a full one.


----------



## Paintguy (Oct 31, 2005)

Missed your post whilst typing Dave - thanks for that. I totally agree with your 3rd paragraph, the more clear you remove now, the less you have to play with later. 

I'd be very interested to read the articles you mention if it's possible. As I was trying to say in my post, I wasn't aiming to be argumentative and say rmorgan was wrong, but rather it's something I'd like to research further so was hoping to get some links to further information 

I've yet to come across the effect myself, aside from the widespread failures some manufactures had when initially experimenting with water borne basecoats and UHS clears, but just because I haven't seen it doesn't mean it's not happening (I'm not that conceited, lol)


----------



## dooka (Aug 1, 2006)

Paintguy said:


> I'd love to know how you get on. Not very well I'd guess.
> 
> Whilst dry sanding is great for bodyshop type work, the grades required for detailing are so super fine that they'll get clogged up very quickly with sanding residue. Even coarser grades like P1200 need a stearate lubricant built into them to help them shed this residue, so when you move to something like P3000 for example you can expect to get through one hell of a lot of paper. Using these super fine grades wet is a much better idea, as the water helps to wash away the residue, which not only makes sanding more effective, it helps the abrasive to last longer, and reduced clogging significantly reduces the risk of deeper random scratches being imparted by the 'clumped' residue.


Check out the 3M 260l discs, equivalent to 2500 and 3000 grit wet and dry..


----------



## KennyC (Aug 11, 2008)

qstix said:


> Check out the 3M 260l discs, equivalent to 2500 and 3000 grit wet and dry..





3M_USA said:


> For use in scuff sanding before painting, as well as to remove runs, dust nibs, and excess orange peel from topcoat finishes prior to compounding


They just sound like Scotch-Brite pads that can be used on the DA

http://www.tcpglobal.com/3m/ItemDetail.aspx?ItemNo=MMM+7448


----------



## Paintguy (Oct 31, 2005)

qstix said:


> Check out the 3M 260l discs, equivalent to 2500 and 3000 grit wet and dry..


Yes, I've been using the 260l discs for years, and the finest grade available (iirc) is P1500. As I said in my post, these discs use a stearate lubricant to stop the discs becoming clogged by sanding residue.

Because they are used on a random orbit sander, the sanding pattern they leave is equivalent to a finer grit linear scratch in some ways, but they still cut much deeper. The usual practice in my bodyshop is to initially sand with a 260l disc (1200 or 1500), then refine further with a damp Abralon pad (2000 or even 4000) or a 3M Trizact (3000), before polishing. Whilst polishing 1200 grit marks is possible, because of the the die back associated with clearcoats (due to it's thermo-plastic nature), they can sometimes return as the surface cools, so refining with a finer grit sanding pad first is highly preferable


----------



## m33porsche (Jun 10, 2007)

There have been some fantastic ws details posted on here and the appeal is obvious, I wonder if we are going to see a gradual increase in the number of studio examples?

However, I do wonder about the wisdom of doing this. In creating the perfect finish you immediately create a surface, that while looking fantastic, will show any minor blemish, literally no where to hide. You have also increased the risk of burn through on subsequent polishing that will inevitably follow to keep theat pristine look.

Be interested in the views on here..


----------



## dooka (Aug 1, 2006)

Paintguy said:


> Yes, I've been using the 260l discs for years, and the finest grade available (iirc) is P1500. As I said in my post, these discs use a stearate lubricant to stop the discs becoming clogged by sanding residue.
> 
> Because they are used on a random orbit sander, the sanding pattern they leave is equivalent to a finer grit linear scratch in some ways, but they still cut much deeper. The usual practice in my bodyshop is to initially sand with a 260l disc (1200 or 1500), then refine further with a damp Abralon pad (2000 or even 4000) or a 3M Trizact (3000), before polishing. Whilst polishing 1200 grit marks is possible, because of the the die back associated with clearcoats (due to it's thermo-plastic nature), they can sometimes return as the surface cools, so refining with a finer grit sanding pad first is highly preferable


Absolutely right, this is how I've been doing it, and was how I did it when in the motor/body shop trade..

Detailing is taking what body shops have done for years, but taking the practice further and to a higher level. Mainly due to time and cost. As customer is coming to us for a specific job ( detailing ), and paying for that job. Spending 2 days detailing a car that has come in for some paint is viable or cost effective in a body shop, but it is nice to be able to transfer my/our skills over to detailing..


----------



## uberwax (Feb 14, 2006)

Thia may be a stupid question but here goes.

Does adding another layer of clear to a car get rid of hte op, or does it just cover it up leaving it further inside the clear?

Just some thoughts as i can see two ways around this if it is thought too much clear is removed. Ie get it sprayed with a layer of clear before, or get it sprayed with a layer afterwards.

Yes would be very costly but if you want that perfect finish with some clear to play with afterwards.


----------



## dooka (Aug 1, 2006)

m33porsche said:


> There have been some fantastic ws details posted on here and the appeal is obvious, I wonder if we are going to see a gradual increase in the number of studio examples?
> 
> However, I do wonder about the wisdom of doing this. In creating the perfect finish you immediately create a surface, that while looking fantastic, will show any minor blemish, literally no where to hide. You have also increased the risk of burn through on subsequent polishing that will inevitably follow to keep theat pristine look.
> 
> Be interested in the views on here..


This is where people will say get a ptg, but if you don't get a really good one, that will measure each different type of paint on the panel. If not, I feel these are a fair waste of money, as you only know the total thickness of paint on the panel, and not how thick you top coat is, so you may well be removing to much and cause strike through, especially if it has been polished or wet sanded before..


----------



## Paintguy (Oct 31, 2005)

pomme said:


> Thia may be a stupid question but here goes.
> 
> Does adding another layer of clear to a car get rid of the op, or does it just cover it up leaving it further inside the clear?


There are no stupid questions, only stupid answers! 

Depending on how the extra clear is applied, there may be some levelling of the OP, but it won't be completely removed as the new clear will conform in some way to the 'contour' of the original substrate.

What tends to be done a lot in the custom painting field is that the item is painted and cleared then allowed to cure ('dry'). Any OP present is then flattened down with a fairly coarse grit paper (which will also significantly reduce the thickness). Another layer or two of clear is then sprayed over the top of this, usually slightly over-thinned to make it flow better (so often called a flow coat). Because these additional layers of clear are going over a very flat surface, the final result is also very flat.The extra layers also 'top up' the clear, to account for the thickness lost during the sanding stage.

And to answer your other question - yes, it would be perfectly feasible to spray extra clearcoat onto a car where correction has reduced the thickness beyond reasonable limits. The main problem with it though is that extra sanding would be required for this extra clear to adhere to. If the original clear is already pretty thin, this could lead to a strikethrough.

There's also the issue that extra layers of clear may darken or yellow the cars colour very slightly, but if the whole vehicle is being done then it wont really be noticeable.


----------



## m33porsche (Jun 10, 2007)

If I could afford it I'd go for a custom paint job as described by paintguy.

The process of spray, cure, ws and flow coat sound to me like the best of both worlds, smooth surface AND glass like finish. Only downside thou would be cost, I guessing it's expensive?


----------



## PJS (Aug 18, 2007)

dholdi said:


> This is all assuming the op is in the clearcoat and not the base.


Assuming we're talking of non-factory additional painting for the sake of this argument, then you're unlikely to find orange peel originating in the paint layer - it's too thin, and the paint used is very different to the clearcoat used, so it won't support heavy-handed application without creating runs.


----------



## MAXI-MILAN (Oct 26, 2008)

i tried sanding by hand 2500 i got good result but i remember when i used 1500 sand paper i got better result to remove orangepeel.


----------



## Paintguy (Oct 31, 2005)

PJS said:


> Assuming we're talking of non-factory additional painting for the sake of this argument, then you're unlikely to find orange peel originating in the paint layer - it's too thin, and the paint used is very different to the clearcoat used, so it won't support heavy-handed application without creating runs.


Yep, peel in basecoat isn't very common these days, and it usually only occurs when the primer layer underneath hasn't been sanded enough, so the base conforms to the peel in that. So it isn't really basecoat peel at all, just primer texture being highlighted by the base 



MAXI-MILAN said:


> i tried sanding by hand 2500 i got good result but i remember when i used 1500 sand paper i got better result to remove orangepeel.


Yes, for cutting down peel a coarser grit will always be more effective, just much more risky and generally needs refining with a finer grit before turning to the polisher.


----------



## PJS (Aug 18, 2007)

Paintguy said:


> Yep, peel in basecoat isn't very common these days, and it usually only occurs when the primer layer underneath hasn't been sanded enough, so the base conforms to the peel in that. So it isn't really basecoat peel at all, just primer texture being highlighted by the base


Indeed, and as wet-on-wet is pretty much all been done away with, you don't get paint sagging due to that method of application, creating the orange peel.
So it's fairly safe to presume any factory paint's orange peel is definitely in the clear.


----------



## Kelly @ KDS (Aug 4, 2008)

Paintguy said:


> Yes, I've been using the 260l discs for years, and the finest grade available (iirc) is P1500. As I said in my post, these discs use a stearate lubricant to stop the discs becoming clogged by sanding residue.
> 
> Because they are used on a random orbit sander, the sanding pattern they leave is equivalent to a finer grit linear scratch in some ways, but they still cut much deeper. The usual practice in my bodyshop is to initially sand with a 260l disc (1200 or 1500), then refine further with a damp Abralon pad (2000 or even 4000) or a 3M Trizact (3000), before polishing. Whilst polishing 1200 grit marks is possible, because of the the die back associated with clearcoats (due to it's thermo-plastic nature), they can sometimes return as the surface cools, so refining with a finer grit sanding pad first is highly preferable


Now thats makes such a pleasant change that paint guy writes clear and simple information thats you can see comes from experiance and not keyboard warrior :thumb:

And i am not trying to agree with paintman for browny points just nice to read on a forum very good information

i swapped private mail with PJS last week about the subject .

Some of the content i sent to PJS

"The new water bourne paint does not actually fully cure anymore and can stay soft , they are still moving around and re cure when baked or in strong sun . Its more a plastic than ever before"

As you can see paint guy can write it far better than i can :lol:

i have found a few cars that have been machined with aggressive cut and look ok , and then when rebaked the car or left sitting in direct hot sun light the paint as said by paint guy "die back" which i call drop back , only too look shocking a day or so later .

I have found now that i refine far longer than i used too or 2 stage refine , this is to stop the problems with drop back once the paint has warmed and cooled a couple of times . :thumb:



Paintguy said:


> There are no stupid questions, only stupid answers!
> 
> Depending on how the extra clear is applied, there may be some levelling of the OP, but it won't be completely removed as the new clear will conform in some way to the 'contour' of the original substrate.
> 
> ...


This is some more of the content a sent him about clear coats etc

"i have repainted cars in the past full repaint 3 heavy clear coats place on long bake , leave for a few days wet sand and then repaint with just clear coat to get the perfect build for the flatest finish .

The only problem with a very heavy multiple clear layers is the colour and metaliic actually looks dull compared with a very thin clear coat . this is because depending on make and type of paint clear coat is not perfectly clear , its full of additives .

So the strange thing is the colour of a car comes out stronger if slight when your are close to breaking through the clear coat , and the trained eye can sometimes spot this . "

When i wrote to PJS that paint 3 heavy coats of clear then wet sand and re-coat , that was the older medium solid (solvent) paints , the new systems it is possible to paint 1-2 coats of clear coats .

I am sure PJS will resure what i wrote 

Here is are some pictures of a car that had been repainted for the customer and said looked ok for a week of so then left it in the sun and this happened (some of this i am sure which i noticed while machine correcting the paint was due to cheap materials)



















The owner said it looked perfect when he picked up the car and there is no way that just a bodyshop glaze/filler could ever hide all of the above

Kelly

www.kdsdetailing.co.uk


----------



## Kelly @ KDS (Aug 4, 2008)

May i add guys for new bees to wet sanding for every car i have wet sanded i must of turned away 4-5 request for wet sand detail . 

The car paint depth and customers understand for the process did not warrant the outcome . 

And nearly all the wet sand corrections i have done in the past are on re-paints by my own company so we know that there is enough scope for such process and the re-paint was adjusted to suit the wet sand process .
And if it went wrong was no big deal to us . :thumb:

Kelly


----------



## Paintguy (Oct 31, 2005)

It seems like we agree on a lot of things Kelly - there must be some truth in what we're saying then 

Just to touch on a few things you've mentioned, for those that want a bit more detail - water borne pains are indeed quite different to solvent ones, and are mostly latex based, very similar to household emulsion paint really, just much more refined.

And what you mention about the colour change just before breaking through clearcoat- that's one of the reasons why I've never used a PTG, as I can usually tell when I'm getting too close for comfort. Although it's impossible to rely on this method for large areas I'd say, it comes in handy for local scratch removal etc 

Die back, drop back - I use both terms. And like you I've found a 2 stage process with a 'cooling off' period helps immensely. The trouble is I've got an old guy working for me that does most of our flat & polish work, and no matter how I try I can't get him out of his old school ways. After sanding he'll hit a panel with excessive amount of aggressive compound (Fast Cut Plus), give it a quick wipe over when he thinks he's done, then go straight over with some machine glaze. Then he wonders why we get so many cars coming back after pressure washing with visible sanding marks!

A prefer to polish once with the freshly painted panels still masked up (also helps to keep the job clean), clean the panels thoroughly to remove all compound residue, then de-mask while they cool fully. A quick run over after half an hour or so with the same or finer compound (never a glaze) and I know the job won't bounce back to me :thumb:


----------



## alan_mcc (Oct 28, 2008)

I wetsanded and refined (with a rotary) with no PDG or experience at all. Just read a few guides. 

:thumb:


----------



## Nikon1149 (Oct 1, 2009)

The bonnet on my car has hologram marks just like that, although not as severe.

Exactly the same pattern/visual effect though, I wonder if that explains it...


----------



## PJS (Aug 18, 2007)

qstix said:


> This is where people will say get a ptg, but if you don't get a really good one, that will measure each different type of paint on the panel. If not, I feel these are a fair waste of money, as you only know the total thickness of paint on the panel, and not how thick you top coat is, so you may well be removing to much and cause strike through, especially if it has been polished or wet sanded before..


Sorry, disagree with your assumption there.
A "regular" PTG when used in conjunction with your brain, and some easily found knowledge, is very effective in assessing how much clearcoat you've probably got to play with.
I know car manufacturers use ones costing around £30K, but then would you expect anything less than laboratory grade equipment in such situations?

The point being made, is that a regular PTG used on a door shut/sill/under bonnet, and compared to the outer panels, will give you a difference reading.
This difference, along with the tolerance of the unit, will give you an idea of the thickness you have available to work upon.
Having done my research (like I always do), and spoke with a number of manufacturers about why they haven't a gauge in their line-up that measures paint on plastic/composite, all said the same thing - they consider the material and the paint layers to be too close in reflective terms, that the figures provided aren't accurate enough to be relied upon.
So, if that's the case, then there goes your theory unless you suggest we all start investing in measuring devices worth more than our car(s).

Detailing is as much about using more than a modicum of common sense and knowledge-based judgement, as it is about the science.


----------



## adam87 (Dec 11, 2008)

alan_mcc said:


> I wetsanded and refined (with a rotary) with no PDG or experience at all. Just read a few guides.
> 
> :thumb:


Anyone can wetsand mate, but it's all about doing it safely and knowing what it is you are actually doing to the car. Wetsanding seems to become a bit of a game to some people who see what is done from the experienced pros with a healthy business, who know what they're doing, and then try to replicate it on their pride and joy or even someone elses, often with terrible consequences. Just remember when you lose the game, it's going to hurt the car, your wallet, and yourself.


----------



## Andrew M (Nov 17, 2006)

Hi Guys,

Have just got to say that this is becoming a fascinating thread/read with some really useful, authoratative opinions . One of the most interesting to me for a while. Thanks to you all for posting in it with such open help, knowledge and information that home based enthusiats like me would otherwise not have access to .

Andy


----------



## Nikon1149 (Oct 1, 2009)

Andrew M said:


> Hi Guys,
> 
> Have just got to say that this is becoming a fascinating thread/read with some really useful, authoratative opinions . One of the most interesting to me for a while. Thanks to you all for posting in it with such open help, knowledge and information that home based enthusiats like me would otherwise not have access to .
> 
> Andy


+1:thumb:

Certainly, i've been checking back regularly. Threads like this is why I love DW.


----------



## big ben (Aug 25, 2009)

its certainly making me think twice about wet sanding one of my cars...


----------



## alan_mcc (Oct 28, 2008)

adam87 said:


> Anyone can wetsand mate, but it's all about doing it safely and knowing what it is you are actually doing to the car. Wetsanding seems to become a bit of a game to some people who see what is done from the experienced pros with a healthy business, who know what they're doing, and then try to replicate it on their pride and joy or even someone elses, often with terrible consequences. Just remember when you lose the game, it's going to hurt the car, your wallet, and yourself.


It was a key scratch repair it was on, i was trying to avoid a respray at all costs, so i thought if i ruin the paint well it'd be going in for a respray anyway.

Wouldn't have done it otherwise!


----------

