Tech Tip #101
Paint defects.
If I could make one statement about paint problems, it would be that all paints are chemicals that react the same in way, regardless of the brand. There may be subtile difference among paint brands (resins they use, solvents they use, etc) but for the most part, the problems that painters have are caused across all paint brands and the solutions are the same.
A chemist I know often told me, "PAINT AIN"T SMART." Paint don't know who you are, what color you are or how skilled you are. Paint has no brains, it always acts the same, figuring this out sometimes is really the problem.
I have been in the paint business going on 43 years now, and for the most part the same tech problems are caused by the same problems. That being said, it is often great detective work to solve some of those issues that arise that seem to have no explanation. That detective work usually takes YEARS to learn! That's why I always tell people to call our tech department with problems, don't rely on other painters.
Back in 1984, I was in the business less than five years and learning new things every day. I was running a paint store in Stuart Florida when the body shop manager of John Jochem Chevrolet a large customer of ours, called and said everything they were painting was full of fisheyes.
Well, I knew what caused fisheyes, however finding the problem was beyond my knowledge. I checked the paint line-filters, changed them, changed the air hoses and had them steam clean the entire booth. Still the fisheyes.
Our product was blamed.
I called our main tech guy. His name is Larry Hall. A giant of a guy whose presence usually stopped anyone from being an idiot when they had problems blaming the paint. It almost never the paint.
Larry showed up, looked around and in 5 minutes asked how long the BBQ restaurant was near by. It had been there less than 3 months (when by the way the problems began.) Larry took us outside and with a rag wiped the side of the metal walled bodyshop and it was full of grease.
“That's your problem,” he said. Nobody wanted to believe him, including me. He got new intake filters, we sprayed 3 cars that day, no fisheyes. He then explained, that you are going to have to change the intake filters every week, or the first sign of a fisheye. The problem went away. Eventually to their benefit, so did the restaurant.
A second “unknown” cause of fisheye that I encountered working with Larry was at a truck repair facility in Stuart. Again, I didn't figure it out and Larry asked the painter, “when you drive the diesel trucks in the spray booth how long do you keep it running?”
What difference could that make? Well diesel fumes are the number one cause of fisheye contamination in truck painting shops. The fumes are greasy and go everywhere. It takes flawless maintenance and cleaning to prevent fisheyes in diesel environments. The problem seemed unsolvable to me, but it was the same factor that causes every single case of fisheye – contamination! Yes, solving the source may be a trick, but when one realizes the universal cause, then that is the trail you follow.
Readers of my posts are probably aware of my distaste for polyester primers. They are garbage! I learned this when I first became a paint rep (still under my education from Larry and also the chemist at American Lacquers.)
A bodyshop repaired a corvette (fiberglass 60's). The owner's girlfriend got mad at him, took a knife and scratched “Fuck-you” all over the car. The shop poly primed the entire car and painted it with Amerflint II.
Three months later the “F-you's” came through like ghost flames! I was stumped, and Larry instantly told me the polyester primers are junk chemistry, and using it on the car was the problem. I asked our chemist at the time, a man named Herb Clann who invented Amerflint II. He agreed.
The proper repair? Fiberglass is porous once the gelcoat is broken. It becomes a sponge. The only repair is a good 1:1 High build TRUE epoxy that acts like cement on fiberglass. Nothing can penetrate a fully cured epoxy resin at at least 3 mils thick. This is why in the marine world, ONLY epoxies are used as primers, especially under the waterline. Even gelcoat itself is inferior to epoxy primers.
They sanded the vette, used our epoxy primer and repainted with Amerflint II and the car never came back.
There is a guide I recommend to everyone to keep handy. I keep the pdf on my phone and computers.
It's called Troubleshooting Refinish Problems:
https://coastisi.com/wp-content/uploads/pdfs/Paint%20FinishTroubleShootingGuide.pdf
You will se the cause of probably every problem you will ever have. You may have to do some detective work, but you know really what to look for.
Frankly using our Facebook 411 page to answer such tech questions can really cause you more problem, because many of the solutions are from people who think they know the answer, when many times will actually make your problems worse.
I tell people instead of using the 411 page, call our tech rep Pat Dry. 757-627-9551 option 3, or better, what with him on our chat feature on tamcopaint.com!
Here are other guides. Regardless of the paint company – the answers are the same:
https://www.bodyshopbusiness.com/paint-problem-troubleshooting/
https://uk.ppgrefinish.com/en/paint-defects/
https://issuu.com/spieshecker-info/docs/tsg_eng-int_es
https://www.youtube.com/watch?v=eRJdNyJuD9g&list=PLRYVQSefZPyF9HnndId4HBPlex5QKhSVn