Originally Posted by dodgeboy3406
Thanx for the response Ray. Look'n back here's what I think happened. I shot the first coat of clear on a cool dry morning with medium activator, outside. It seemed to be taking a loooong time to flash. I waited a good hour and still "runny" The sun started to come out and the clear started to "firm" up. I then shot the second coat kind of heavy. Now I have too much sun and the second coat flashed up like normal but with these tiny bubbles on the parts exposed to the sun.
To answer your questions, yes some were there pretty quickly some "developed" over time. They are so small I could not see most of them when I compounded the clear in my garage under florescent lights. When I took the parts outside in the sun, to check for color match that is when I seen the extent of them. The surface is like glass. Smooth, shiny and hard. I was going outside looking install these trim pieces, they look that good....cept for the bubbles. I wet sanded the parts about a week after painting and then compounded about a week after that. I know not to rush those steps as you can cause the same solvent problems by sealing fresh paint with wax. No wax has been applied just compound.
Thanx for your help.
Yes, the way you explained how, when and under the conditions the vehicle was cleared, you have a recipe for "solvent popping", especially with a little breeze and the sun warming up...Basically what happened is, cool temperature, but constantly getting warmer, the clear starts to cure but, the top of the clear (being in the sun and warming up) skins over. Underneath the skin is clear that still has solvents in it. In order to get chemical adhesion, these solvents travel down to the metal drawing the active component molecules of the product down with it. These molecules lock into the sand scratches (mechanical adhesion) and the molecules of your substrate (primer, existing paint whatever = chemical adhesion). When the solvents hit the metal they bounce upwards trying to escape, completing the curing cycle. The problem is they have a hard time escaping because the top of the clear that was just applied has skinned over. They build up like a volcano and eventually POP. That's why they call it "solvent popping".
Not that this explanation is going to make your repair easier, hopefully it will help you understand a little the chemistry and the reaction these chemicals have when conditions either change or a "perfect storm" is created. In your case, you had a bit of both.
I mentioned in one of my previous posts how to repair your situation...If you need more information or have questions, just ask and I'll try and help.