Lacquer paint checking question

[Shawn1283]

I have a car with it's original acrylic lacquer that had been garage kept until last November. I am now starting to see checking on the horizontal surfaces. What exactly causes this? It isn't in direct sun often yet this happened. Is it the temperature changes? I wish I could smooth it out. The car has been waxed and well maintained prior to this.

[SHYNEMAN123]

Re: Lacquer paint checking question

What year and make is your car ?

[Shawn1283]

Re: Lacquer paint checking question

This is on a 1987 Chevy Caprice coupe in white.

[Mike Phillips]

Re: Lacquer paint checking question

Moved out of Hot Topics and into Detailing 101

Hot Topics are for typically questions that come up all the time and "we" deem worthy to be placed into the "Hot Topics" forum.

All other questions should be posted to either Detailing 101 which is a catch-all forum for anything or one of the other sub-forums not in the Information Station.


Thank you!

[the other pc]

Re: Lacquer paint checking question

Why do you think it’s lacquer? By ’87 pretty much all cars were painted with enamels.

Anyway, there is no way to repair checking (a.k.a. cracking, crazing, splitting, alligatoring, crowsfeet). You have to live with it or re-paint.


PC.

[Mike Phillips]

Re: Lacquer paint checking question

This is on a 1987 Chevy Caprice coupe in white.

Doesn't sound right that GM was spraying acyclic lacquer in 1987

Maybe I guess?

Regardless there's nothing you can do to fix Lacquer Checking as it's a crack, or multiple cracks that are throughout the paint, not just on the paint.

Thus is you try to abrade the paint in an effort to remove it all you do is remove paint and expose the cracks deeper and deeper into the paint until you hit primer.

There's probably a number of reasons for lacquer cracking but one could be lack of flexibility in the paint so over time as it expands and shrinks with the panel that expands and shrinks when exposed to heat and cold temperatures the paint cracks.

Besides the above it could also be a paint application problem that shows up as lacquer checking or cracking over time.

[Shawn1283]

Re: Lacquer paint checking question

It's definitely lacquer, I compounded it not too long ago. It says so on the options tag in the trunk. I figured there wasn't anything I could do. :p

[Mike Phillips]

Re: Lacquer paint checking question

Wish we had an in-house paint guru, as in someone with a background in the chemistry of paints used in the automotive world.

Wish... wish.... wish....

Anything happen yet?

[ClassicConcepts]

Re: Lacquer paint checking question

That's a nature of the beast with lacquer. As it ages, lacquer shrinks and cracks. Usually is is worse where it was applied heavier, some of the custom paint jobs years ago were really bad because the heavy application of clearcoats. What we did do that sometimes helped was to try a coat of a small amount of clear with a lot of thinner. Sometimes that would "melt" the old finish and blend it a bit, but it was a temporary fix. In some cases it would ruin the finish, but at that point we were looking at a total repaint anyway. Wish there was an easy fix, but there isn't.
A good example of a lacquer finish with cracks is the 54 Chevy in my avatar. They aren't big, but I'll live with them till I do a repaint.

[SHYNEMAN123]

Re: Lacquer paint checking question

doesn't sound right that gm was spraying acyclic lacquer in 1987

maybe i guess?

Regardless there's nothing you can do to fix lacquer checking as it's a crack, or multiple cracks that are throughout the paint, not just on the paint.

Thus is you try to abrade the paint in an effort to remove it all you do is remove paint and expose the cracks deeper and deeper into the paint until you hit primer.

There's probably a number of reasons for lacquer cracking but one could be lack of flexibility in the paint so over time as it expands and shrinks with the panel that expands and shrinks when exposed to heat and cold temperatures the paint cracks.

Besides the above it could also be a paint application problem that shows up as lacquer checking or cracking over time.

it is poss. Might have been a fleet vehicle maybe even a police car of fed. Govt.

[Shawn1283]

Re: Lacquer paint checking question

No chance of that, it's a two owner car, and a loaded coupe so definitely not any commercially-used vehicle. From my experience it wasn't until '88 that GM went completely bc/cc. It is lacquer- it says so right on the options tag on the underside of the trunk. Besides I've worked with it many times on cars and I'm aware of the differences, it's obvious.

I guess I'll just work with what I have, it's still very shiny, it's just that on closer inspection you can see the age of it. I have an '83 Pontiac in a different color and that didn't crack, but it did dull and fade on the top surfaces. Thanks for the info everyone.

[SHYNEMAN123]

Re: Lacquer paint checking question

Do you have a mill gage ? Or have you had the film thickness checked?
I have done several gm vehicles in the early to mid 80's with lacquer cracking olds toranado, cadillac eldorado's that had cracking on the hood and deck lids. These two were light metallic.i was able to buff them with a 3m product and a wool pad to generate enough heat to re flow the paint with out burning it and removed the cracks.these cars were a wholesaler's and went to auction so i do not know how long the repair lasted.