# Paint depth results - your opinions please!



## Gone (May 5, 2009)

I'm planning to lose my machine polishing cherry in a few week's time so in preparation I borrowed a PTG (Elcometer 456 with F1 probe) from work and took a bunch of readings. I knew the car had had some re-finish work done previously and wanted to check the extent of the job. I calibrated over steel with a 130 micron standard first. Here's some results (microns):

N/S front wing: 194, 218, 185, 197, 182, 172, 185, 211 (over wheel arch 199)

N/S door: 213, 246, 245, 218, 246, 231, 263, 272, 222, 214, 235, 220

N/S rear Q-panel: 308, 285, 398, 383, 277, 280, 289, 270, 233 (over wheel arch 276, 252)

N/S sill: 140 (front), 144, 164, 171, 180 (rear)

N/S roof edge: 270 (front), 266, 249, 225, 244, 252, 232, 244, 250 (rear)

O/S measurements were much the same - 250 - 300 micron

Roof: 108, 118, 117, 108 along front edge
122, 138, 134 along N/S edge and 108, 123, 137 along O/S edge
117, 118, 124, 117, 141, 131 in the middle

Tailgate: 128, 124, 124, 111, 120, 112, 119, 115, 129, 108, 121, 117, 120, 117, 119

Couldn't do the bonnet or bumpers are they're plastic or non ferrous metal.

So to come to the point I conclude that everything has been resprayed at some point except the roof and tailgate.

It's a good job so I assume it was done properly by a qualified garage, although there is nothing in the history about it. 
How tough is re-finish paint? How thick is the clearcoat over the new job? How careful do I need to be with a DA polisher?

Appreciate the answers to these questions will require assumptions etc. I'm just after some reassurance! Don't want to let rip and find primer after a few passes!


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## Gone (May 5, 2009)

Really just after some advice lads. Anyone?


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## TT Ade (Aug 20, 2007)

No idea, sorry.

Do you know what an average paint thickness would be when the car was new?


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## ecko2702 (Jan 26, 2009)

badyaker said:


> Really just after some advice lads. Anyone?


You should be fine without nothing what material they used when they did the respray it's hard to say. The factory paint has a very hard clear coat so you can't do to much damage if you have half a brain any ways.
If you have never buffed or polished a car I can give you tips as I buff cars as a side job and worked in a body shop. I don't know what sort of DA yo have but you will want something with selectable speed settings. Turn it to it's slowest setting. Slower will build up less friction so it takes longer to burn the paint. Also use a smaller polishing pad the smaller the better as the smaller they are the harder it is to swirl the finish. Keep the DA flat on the finish DO NOT angle it forward to use the edge of the pad you can swirl it doing that unless your experienced. It is very easy to do and not something to be put off about doing. If you have any more question let me know


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## Gone (May 5, 2009)

Hey cheers for that. I know without knowing the details of the job you can only speculate! Normal finish should be around 100 microns, so the story goes from other posts I've seen.

I guess if I just follow the usual procedure of starting with the least aggressive pad and polish combo, not much can go wrong  may have to step it up a level for the OEM bits.

Got loads of swirls and some fine scratches that must come out. I plan to go for a mutli speed dual action machine with a 5" pad, looks similar to a G220 or porter cable. Sure you've seen the one on cleanyourcar.co.uk - with the Menzerna package.


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## ecko2702 (Jan 26, 2009)

The only way you can really do damage is by cutting the paint back to remove deep imperfections. Polishing doesn't cut back a whole lot. Use a foam pad for what you describing foam will work and wool will be to aggressive


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## Gone (May 5, 2009)

[smiley=thumbsup.gif]

I'll post up results when I'm done!


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## dooka (Apr 28, 2006)

looks like your car has had paint work..

Try measuring the inside of the door shut, on the door it's self, just by the lock, usually less paint here, so that will give you a good indication of how much paint you have to play with..

110 - 135 is around average for most cars, but can always vary..


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## BLinky (Jul 3, 2009)

roof ever so tiny bit thin, but everything else is fine. like all modern audis you have loads of paint. btw it'll take ages to do a perfect job audi paint is insanely hard.


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## davelincs (Jan 1, 2010)

not sure if this link will be any use to you badyacker
http://dodojuice.com/forum/viewtopic.php?t=1045


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## Gone (May 5, 2009)

Hey cheers there. I know it's had paint done - and I think it's just a new clear coat. My theory is basically vandalism down both sides at some point in the past. I know Audi paint is very hard but as the job wasn't done by Audi I doubt it's Audi paint.


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## dooka (Apr 28, 2006)

Paint on roofs, does usually tend to be slightly thinner on the roof than other panels, don't ask me why, just something I have found in my experience..

Paint around panel edges also tends to be a little thinner..


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## MrHooky (Oct 27, 2009)

Badyaker - have a look at this link - http://www.cleanyourcar.co.uk/show-n-sh ... fo_28.html

Although they don't quote depths all over the car, they said 180 was for a known car owned from new with no resprays so your car may not have been resprayed after all. I also read somewhere (can't remember where) that a respray would take it far far higher although I might be wrong there.

Love that black TT in the link and the results they got there...


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## Gone (May 5, 2009)

Cheers that's another useful link.

I'm pretty sure it has had some work as there is a sheen difference between the roof/tailgate and all the panels - the OEM areas are dead flat with sharp reflections, but the reflections in the re-finish are slightly dappled. I hadn't noticed until I took the readings, I expect it'll come good after the polish.


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