# How many full corrections can a car take



## amclean (Jul 29, 2008)

OK, being a fairly new member here, I see many newish cars (12-18 months) having full corrections done to remove swirls etc.

How many full correction processes can a modern metallic finish (i.e. clear coat) take before going through to the paint finish?

Any idea anyone?

Cheers
Alan


----------



## reign (Oct 6, 2008)

depends on the paint thickness, level of damage/contaminants, methods,chemicals, and weights used. anyone can burn through paint relatively quickly doing it incorrectly, while some of the professionals on here have so much practice they could detail a car every year for 20 years and still never burn through the paint.... 

so, alot of variables involved in the answer. sorry I cant be more specific.


----------



## mattsbmw (Jul 20, 2008)

The key is to get it correctted properly then maintain the finish with appropriate methods an equipment so that each year it only needs a quick going over with a light cut finishing polish.


----------



## Guest (Feb 7, 2009)

Alan has a valid point though, and there will be a rough answer to it, and no matter how good the detailer if the swirls are x microns deep and they *fully*correct it, then it will go through eventually. I would be intrested to know a rough answer.


mattsbmw said:


> The key is to get it correctted properly then maintain the finish with appropriate methods an equipment so that each year it only needs a quick going over with a light cut finishing polish.


Trouble is 90% of their customers won't and it will get bunged through the carwash at some point.


----------



## richjohnhughes (Sep 24, 2007)

good question mate. 

how thick is the clearcoat? how much removed with correction? 

divide one by the other and thats ya answer!


----------



## Guest (Feb 7, 2009)

richjohnhughes said:


> good question mate.
> 
> how thich is the clearcoat? how much removed with correction?
> 
> divide one by the other and thats ya answer!


Sort of yes - but once the clearcoat is down to a certain thickness (maybe not as little as you think) it will fail and peel off.

Dave KG will be the man to answer this (and others im sure!)


----------



## James_R (Jun 28, 2007)

One of the pro's on here with a Positector will be able to tell you quite accurately how much clear coat he has removed by checking before and after a correction.

Too many variables really insofar as strength of cut from the polish and pad used. 

Also depends too on how bad the scratches/swirls are in the first place.


----------



## Guest (Feb 7, 2009)

I'm not sure, there will be a rough answer, and given we are talking about full correction, it doesen't matter what polish/pad, because you are simply removing the swirls to whatever deepness they are, and you only need a PTG, 

As rich says its pretty simple, thickness of clearcoat, and how much microns are generally removed with a correction, add the static component (say a generous 10% or less CC will result in failure), and you have an answer of how much correction a car can take.


----------



## VIPER (May 30, 2007)

What about solid colour paints? - not everyone has metallic paint.


----------



## drive 'n' shine (Apr 22, 2006)

G220 said:


> Trouble is 90% of their customers won't and it will get bunged through the carwash at some point.


They need to work on their post detailing maintenance sales technique then


----------



## Guest (Feb 7, 2009)

drive 'n' shine said:


> They need to work on their post detailing maintenance sales technique then


----------



## amclean (Jul 29, 2008)

Good stuff everyone. I knew it was a generalistic question with the answer depending on many variables, but thought there may a guestimated average of say 5-10 times for most cars.


----------



## powerPT (Apr 29, 2008)

The stats indicates that, average of layer of clear coat thickness is 80 microns. So, if you remove 10 microns per correction, you can do the same more 9 times.


----------



## drive 'n' shine (Apr 22, 2006)

powerPT said:


> The stats indicates that, average of layer of clear coat thickness is 80 microns.


What stats are these? 30 - 50 um would be the average in my experience on factory finishes


----------



## powerPT (Apr 29, 2008)

I don´t remember, maybe at autopia...


----------



## James_R (Jun 28, 2007)

powerPT said:


> The stats indicates that, average of layer of clear coat thickness is 80 microns. So, if you remove 10 microns per correction, you can do the same more 9 times.


No where near my friend. If you remove 10micron 9 times, you will be stumping up for a respray.
I had three cars parked outside yesterday, each different manufacturers and they each had an average paint finish of 120 microns, I dont think 80 micron of that will be clear coat.

I agree with 'drive 'n' shine' though, 30-50 micron sounds about right depending on manufacturer. [factory finish as you say]:thumb:


----------



## Clark @ PB (Mar 1, 2006)

drive 'n' shine said:


> What stats are these? 30 - 50 um would be the average in my experience on factory finishes


Agreed 

And I'd say you'd only be looking at 10ish microns removed if you were heavily compounding/sanding softish paint.

I removed just over 8 microns of clear removing a scratch from my Impreza (soft paint) with a Polishing Pad, the PC and Menz IP (the old US version) after 4 hits, so on average it was taking 2 microns off with each hit on the panel. Compare this to when I used a Compounding Pad with Fast Cut Plus with the Rotary on a Gallardo (very hard paint) I only removed 2-3 microns max. after 2 hits.

On the majority of cars, perhaps with the exception of the really soft paints, you should be looking at a 1-2 micron removal rate (if that) when nipping out any light wash marring/cob-webbing with a mild finishing polish every 12-18 months...


----------



## Clark @ PB (Mar 1, 2006)

For what it's worth, I took paint readings on a brand new DB9 this morning and the average clear coat readings were around the 40-60 mark and I'd say that's quite generous compared to some cars...


----------



## drive 'n' shine (Apr 22, 2006)

Clark said:


> On the majority of cars, perhaps with the exception of the really soft paints, you should be looking at a 1-2 micron removal rate (if that) when nipping out any light wash marring/cob-webbing with a mild finishing polish every 12-18 months...


Agree, in fact on harder paints I doubt you'd even get a measurable difference


----------



## James_R (Jun 28, 2007)

Thanks Clark and Bryan for the input over the last few posts. :thumb:


----------



## Dream Machines (Mar 13, 2006)

typical australian made cars factory finishes have 110 to 130 microns in total
30 to 50 being the clear

I will only do paint correction twice on a car, from there it's on to non abrasive treatments like Glare, Toughseal, Amigo/Blackfire GEP and Driven Marine sealant
More shine will be attained if you work on the same layer of paint over and over again over a long time period than to remove paint again and again


----------



## mp3turbo (Jan 21, 2009)

DM, twice on a car is too careful. Experience of my friend tells me that Skoda Octavia year2001 was done approx. 10 times (definitely more than 7, because it was done more than once a year ; quite often it was done before winter and after winter so it got performed twice a year) and it is still flawless.

Only one owner from very first beginning, but he was doing the car as "preparation for winter" and then "cleaning up winter traces" 

Unfortunately I don't have paint thickness data at all, not a single info on how thick the paint was when manufactured and how thick it is now.



But definitely, full correction twice on a car is nothing, you are too cautious and pesimistic.


----------



## Dream Machines (Mar 13, 2006)

thank you for your post my fellow DW member
It's all about the depth. remove a certain level or more of the clear and the depth perception is never the same. on a new car, we can all see the clear coat standing above the colour, the more we correct, the more it begins to look like a SS paint finish.

I believe this

That to get the best finish possible, complete two or three corrections and then use non abrasive products including blackfire GEP/Prima Amigo, Driven Marine and Glare and work on the same layer of paint over and over. 

Removing clear coat to get the shine back or to get the best possible result doesn't work.
No matter how good correction and enhancement is, finishing up with 85RD and saying it's as good as it's ever going to get is (sorry DAVE KG) simply not good enough
It is still far away from what can be achieved by working the same clear layer over and over again. 

The vehicles I work on that have had two corrections only and a number of GLARE treatments or Driven Marine after GEP and Amigo, get to a level beyond that of correction, enhancement and final finish and even waxing

build on the paint, don't remove it. do so and you are starting all over again. 
that's what I have done to my Tickford. six GLARE applications to flatten the peel down a lot and amplify the paint lustre. 

one of my customers spends an immense amount of time per panel with Amigo and Driven Marine Sealant glaze by orbital and when looking at it, I could swear that the body was painted with coloured glass.

I know that some of my posts or alotof them may seem ludicrous but many detailers are living in the dark ages when it comes to polishing. abrasives have their place but they cannot provide the best possible finish on their own. 
just like using cutters to fix oxidation. why do that when it can be melted and dried like fresh paint


----------



## drive 'n' shine (Apr 22, 2006)

mp3turbo said:


> But definitely, full correction twice on a car is nothing, you are too cautious and pesimistic.


How is too cautious, say factory finish has an average of 40um of clear you correct it and remove 10+ um leaving 30 now out of that 30 you will want to leave at least 10um - 15um to prevent premature clear coat failure which only leaves you with 15 - 20 odd microns to play with in the fututre which means only 2 (at most) full corrections can be safely done (IMO) but if you need to do that many correction details you seriously need to look at your wash technique!

Are you sure your meaning full corrections or merely a once over with a finishing polish?


----------



## mp3turbo (Jan 21, 2009)

everything you said is correct, there are just two potential contradictions : original paint is not 40um but over 100um (150um is not a problem) and you might not remove 10um by full-pass, it could be 2-5um. This was discussed in this topic already, I guess (or I have seen it somewhere else on this forum, for sure). And that leaves you not just 2, but 20 full-corrections then.

As long as you don't sand the paint... you should be pretty safe. Definitely more safe than 2 passes...

> Are you sure your meaning full corrections or merely a once over with a finishing polish?

oh yes, I'm sure I mean full corrections. The example I provided is owner who can be described as : "he basically cares about his exterior condition but he is lazy and busy enough to wash his car properly so he frequently visits automated car-wash units". This is the reason why he has swirls all over and this is why he lets the car undergo full-pass every year. No damage whatsover in a very long time.

btw what about this one : http://www.detailingworld.co.uk/forum/showthread.php?t=107073

"Due to the severity of the scratch and limited paint to play with on this particular area of the panel (highest spot was 111 microns with the lowest being just under 100) I knew complete correction wasn't going to be possible so the aim was to just improve it.

So using a laser pen (again, I should point out that this was a tip I got from Matt at OYM detailing so all credit goes to him) to gauge clear coat removal, I removed 6-8microns with 2000 and then 3000 unigrit paper before deciding enough was enough."

This was DEEP SCRATCH, wet sanding and ONLY 6 microns were taken off... there is no way how harshness of that could compare to usual abrasive pastes and pads. Sanding is MUCH more cruel, isn't it?


----------



## drive 'n' shine (Apr 22, 2006)

Over 100 um is total thickness of base colour and clear coats, its only the clear that get polished and on factory finishes it averages at between 30 - 50 um.


----------

