Expert: William Forster - 12/17/2006

Question
I recently painted my first car.  I have been around the autobody profession for a while.  This is the first time that I paint a car.  I used Nason ful-thane urathane.  The job came out great.  But a month to six weeks after the job i noticed the paint had all kinds of little bubbles in it.  It appears that the paint and sealer are lifting.  The primer is staying down.  The bubbling is getting worse but they never get big.  THe bubbles are about the size of a pin head and all over the car.  I was wondering if you had any sugestions on what could have gone wrong. Thanks

Answer
Hello Devin! I would say you have some solvent trapping. You probably got on the sealer too fast with paint, meaning you didn't let it dry long enough before painting. You also may have put on too many coats of paint, or put them on too quickly, not waiting long enough between coats. You may have used reducer that wasn't proper for the temperature or humidity level that day. You may have had contamination from a dirty air regulator filter. It's nearly impossible to pinpoint, there are so many variables, and I wasn't there when you painted the car. Experience teaches what needs done, or what not to do, on any given day, with different spray conditions. paint acts differently on a 70 degree day with 30 percent humidity than it does on a 70 degree day with 90% humidity. It takes talent to be a good painter. He can forsee problems before they happen, and eliminate the variables with gun speed, reducer selection, air pressure, and waiting time between coats of paints and sealers. He will also be sure of compatibility of different products. All I can do is guess, Devin. Take what you remember about painting the car that day, and look at my check list. I'm sure that something will jump out, and say it was the problem. The rule of thumb when painting- If it don't feel right, don't do it. Don't take chances when painting, they will always come back to bite you on the ass. Hope this helps, Devin. Good luck to you on future paint jobs, I hear a lot worse from other people. Be glad your first paint job only has solvent trapping. Congratulations! Bill