Paint chip/scratch repair with Bondo putty questions.

[Accumulator]

So if you`re all saying that solvents are bad, the what do you think about Dr. Colorchip and others? They use a solvent to wipe excess paint from the repair areas?

I keep the DR Colorchip solvent off the surrounding paint as best I can, sure don`t let it dwell there. I guess it`s like with Langka...these solvents probably aren`t good for autopaint period but with, uhm....judicious use they don`t *seem* to cause problems. At least they haven`t for me (well, not yet).



Also, note that the DRC touchup paint is pretty fragile stuff, easy to clean/polish/solvent it right off the car even when you`re being careful. A solvent that`ll level that stuff (without removing it, at least as long as you`re really careful and somewhat lucky!) could easily be mild enough to not damage oe paint or even catalyzed repaints and I`ve never had it mess up either (not that I`ve used it all that extensively).



I *do* wonder about using Langka on repaints, but I`ve done it without problems; I used it to remove blobby touchups from a repainted panel and it worked OK. But man-oh-man was I nervous about trying it, and I was being really careful to *not* let it dwell any longer than was necessary to soften the touchup paint in question.

[dfoxengr]

What did you do to neutralize/remove it so as not to let it sit there long?

[Accumulator]

What did you do to neutralize/remove it so as not to let it sit there long?

I do`t really *neutralize* it, I merely wipe it off and it flashes away pretty quickly.



I`d hate for somebody to follow my example and have some terrible "oops!" but it`s never bitten me yet.

[dfoxengr]

So to bring this back, what solvent or method should be used to level the touch ups if Lacquer thinner isn`t worth the risk?



Basically wanting to know what solvent is mild, but won`t leave residue behind that I can level the filler putty and paint with. What about 3M adhesive remover, mineral spirits, etc?



Concours John?

[Concours.John]

So to bring this back, what solvent or method should be used to level the touch ups if Lacquer thinner isn`t worth the risk?



Basically wanting to know what solvent is mild, but won`t leave residue behind that I can level the filler putty and paint with. What about 3M adhesive remover, mineral spirits, etc?



Concours John?

The main problem with leveling fillers with a solvent is they are a catalyzed product. They need the chemical reaction to thoroughly bond and not shrink. Also their application method (spreading) does not lend to a non porus fill (resulting in shrinkage without subsequent primer layer fill). To remove them with a solvent needs to happen before that reaction has finished.



If you look at the composition of fillers there are different grades. Think of foam cell structure. The filler grades would range from fiberglass reinforced (coarse foam, loose density) to spot glazes(fine foam, tight density)



Wiping a filler with a solvent to level will just simply melt the outermost layer. Fillers should be removed by mechanical action, sanding.



There are reducers to thin fillers to change their structure a little. With the advent of products like "slick sand"(basically spray able bondo) it is not necessary. The liquid mix of these products leaves a less porous fill layer reducing shrinkage.(of coarse there are thickness limits.



Anytime you can fill with a liquid base you are better off on touch up work.



As far a solvents for paint. Most paint repair systems are going to use more of a paint reducer(less aggressive than thinner) based glob remover. These are going to be on the least aggressive scale.



I don`t want to mislead anyone.

There are different grades of reducers and thinners. Basically it is their flash time that makes the difference.

Low temp tends to flash quick

High temp slow.



While one with and without experience can get a good result with any of these.

Picking the wrong one can cause problems at the scratch/chip repair perimeter. It`s always best to talk with a paint jobber. Let him know your paint and ask for a suggestion. I myself always ask if unsure of a paint system reaction but know what to watch for when testing.



Forgive my rant I just wanted to explain more of why it is somewhat a technical question based on a system to system basis. Hopefully it helps.

[dfoxengr]

So John, is it a bad thing to level the filler putty with a chemical as the Applied Colors kit does? Basically it looks like they apply the putty, wait a couple minutes for it to start hardening and then level with the chemical.

[Concours.John]

So John, is it a bad thing to level the filler putty with a chemical as the Applied Colors kit does? Basically it looks like they apply the putty, wait a couple minutes for it to start hardening and then level with the chemical.

I would have to look closer at their system.

I am assuming their filler is similar to a ultra fine spot putty.

[dfoxengr]

It`s bondo spot putty/glaze