Wrong claybar usage removes clearcoat.

[Hawkfanatic]

A warning to new clay bar users – When used with the improper technique, it can damage your paint/clearcoat.


Here’s the story:



I picked up a spoiler from a 97-98 Saturn at the junkyard to practice my rock chip repair technique. I am going on the assumption that the fully cured factory paint surrounding the chip is substantially harder than a freshly repaired area. So I fill the chip with paint, and let it dry, and dab a drop of clear on top of that and let it dry. After a few hours I come back and clay bar the spot quite vigorously to try and level the clear dab flush with the surrounding paint. I am weary about using sandpaper to level a repair spot when the surrounding clear is already thin from the factory. After claying this very small area hard and fast for 10-15min, the clear dab is about level with the surrounding paint, and almost invisible to my discerning eye. So my theory is proven. The problem is when I then hit it with some 91% IPA, I got paint on my paper towel, indicating that I had clayed off the clear coat!



I think the problem is this: I used old clay that I have used on a few vehicles, so the clay probably had a lot of particulates suspended in it, and then, with my aggressive rubbing, the clay got paper thin to the point where my finger broke through.



I think that the combination of thinning clay and already suspended solids in the clay made it act like a piece of sandpaper, taking the clear off.

So, moral of the story: Use fresh clay on a vehicle you care about!

[Paul S]

Re: Wrong claybar usage removes clearcoat.

You rubbed the spot for 10-15 minutes ? The use of clay is to remove above surface contaminents , not level paint. A few light passes would be plenty. The condition of the surface will dictate how aggressive of a clay would be required. If I were to repair rock chips 1st I would wash,clay and do a surface prep before applying paint. Giving the paint time to dry (according to manufacturers specs) I would then lightly wet (color) sand the area . Next would be compounding to remove sanding marks as you would do on any paint correction. As for fresh clay , I have had some of my clay for years on a shelf and would use it without a worry. Once a bar is opened I place it in a plastic baggie with a spritz of QD. I re-use it until darkes to the point I see that it is no longer effective.My clay does get very little use now that I have started using a nanoskin prep towel.
A little side note: When doing paint correction on a car that will also need chip repair, I do all of the correction before attempting the chip repair. You will experience some paint if not applied and or cured correctly will come out of the chip. You may want to look into Dr.ColorChip which is far superior to a paint pen or touch-up paint and brush.

[Michael Stoops]

Re: Wrong claybar usage removes clearcoat.

So, moral of the story: Use fresh clay on a vehicle you care about!

Well.............. yes and no.


As Paul points out, this is not really a great way to use clay in the first place. What a lot of people don't really consider when working with clay is that the clay is actually an abrasive product. It works by shaving down those tiny bits of bonded contaminants and collecting those little bits in the clay. If you used clay to level a small touch up spot, then you were doing much the same thing you would have done with sandpaper, except the clay was a much, much finer abrasive. Had you worked a bit of even 3000 grit sandpaper with the amount of energy you describe you probably would have gone through your clear in half the time. And a coarser grit of sandpaper would have gone through faster still, given your description of how vigorously you rubbed the chip repair. When properly done with sandpaper you would have had a backing pad behind the paper that would have caused said paper to only impact the top of the touch up blob and not the surrounding paint (or barely touch the surrounding paint, at the most). That would have leveled the blob and left the surrounding paint with only the lightest of sanding marks, an easy thing to buff out. Incorrect use of sandpaper would involve foregoing the backing pad and just using your bare hand, or as is commonly - but incorrectly - done, your thumb. This method puts some pressure on the top of the paint blob, and plenty on the surrounding paint, and creates sort of a low spot with a high point of the paint blob in the center. Not really ideal at all. By using a piece of clay bar to level the paint blob you much more closely mimicked the bare thumb approach to spot sanding, and after 10 to 15 minutes of vigorous scrubbing you went through your clear. Overall, however, it was the long term vigorous scrubbing in such a concentrated spot that ultimately caused your rub through, not the clay. We've seen people rub through their clear using a very mild paint cleaner and a terry cloth towel in an attempt to remove an isolated, deep scratch. We're pretty confident that we could rub through clear coat using a bit of terry cloth towel and plain water, if we scrubbed hard enough for several minutes.

Please understand that we don't mean to beat you up over this - we're pretty sure you're doing enough of that to yourself already. We just want to make sure that everyone understands the dynamics of what really happened here. You came very close to explaining it when you said

I think that the combination of thinning clay and already suspended solids in the clay made it act like a piece of sandpaper, taking the clear off.

In reality, had you used a brand new piece of clay, we would expect to see the same outcome.

[Hawkfanatic]

Re: Wrong claybar usage removes clearcoat.

Thanks for the explanation, guys, I was under the impression that clay bar was clear coat safe under any circumstances, but Michael, I see your point about using anything with that much vigorous force could eventually burn through the clear. Why can’t cars just be impervious to everything ala Knight Rider??


Don’t worry about beating on me too much, as this is an experiment on a junkyard spoiler – I got it exactly for situations like this.

I have tried wet sanding with 2000 grit on a small block of wood, and got sanding marks all over that make the chip look like a starburst.
I have tried wet sanding with 2000 grit on the end of a dowel rod, and still burned through because I couldn’t hold the rod exactly perpendicular to the panel surface.

I bought a 6” Trizact 3000 grit for my next attempt, but am unsure what to put behind it. I don’t know how to apply it to the blob in order to only touch the blob, and not the surrounding paint area until the blob is almost level.

That’s an interesting point that Paul made about doing surface correction before chip repair. I have a full G110v2 kit on the way and am looking forward to the results it will bring.

[Paul S]

Re: Wrong claybar usage removes clearcoat.

There are a ton of videos on youtube about wet sanding and correction.A Meguiars sanding block can be your friend when hand sanding. I know Mike Phillips had some posted in the past that might be able to point you in the right direction. It just takes some hands on experience to where you feel comfortable doing it.Good luck.

[h_bomm]

Re: Wrong claybar usage removes clearcoat.

I've seen in other posts that people will tape off around the blob so that there is only about 1 square inch or so of exposed paint to try and minimize unwanted scratching

[Michael Stoops]

Re: Wrong claybar usage removes clearcoat.

Thanks for the explanation, guys, I was under the impression that clay bar was clear coat safe under any circumstances

Therein lies the rub (no pun intended). There is NOTHING that is clear coat safe under any circumstances. But on the flip side, virtually EVERYTHING designed to be used on paint for detailing purposes is 100% totally safe when used properly.

[CreamPuff]

Re: Wrong claybar usage removes clearcoat.

100% totally safe when used properly.

Now you tell me this? Just kidding.

[CHzo6]

Re: Wrong claybar usage removes clearcoat.

91% IPA should never, ever be used on paint that you care about.

[Hawkfanatic]

Re: Wrong claybar usage removes clearcoat.

91% IPA should never, ever be used on paint that you care about.

Why? Please explain. What would be better for de-waxing?

[h_bomm]

Re: Wrong claybar usage removes clearcoat.

A car wash with dawn soap will remove wax

[CHzo6]

Re: Wrong claybar usage removes clearcoat.

91% is far too strong for paint, it can cause serious issues. Most paints will allow alcohol to seep into it and can soften or "wrinkle" the paint, which I've seen done by a decal / lettering installer. If you want to use it to "de-wax" with, you should use about a 10-15% solution.
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