I am working on chopping and painting a Harley fender for a guy. I have chopped it and painted it 4 times and still having problems. I painted and did body work for a living almost a year ago (now I only do it on the side) and have never had this problem. I prepped the fender after chopping it, and used all SPI primer and clear with SPI reducer and activators. I first epoxy primed it with SPI and let it sit for a day to dry and breath out before wet sanding it. After it was wet sanded and prepped I hung it up in the garage which was well heated and heated the metal to room temps. Precleaned with solvent and water (glass cleaner that I've always used with no problems) based wax and grease remover. Sprayed my 3 coats of base with correct flash times between coats. Let the base dry a few hours and sprayed the clear. Everything mixed correctly, all new materials with Nason black base and then tried PPG Omni base with same problem. The base and primers went on perfect, not a single problem there. As SOON as I sprayed clear it went on and tiny tiny bubbles all over and then pinholes when dried with bubbles underneath. I did my first medium coat and then second wet coat like always. I have used this clear many times and sprayed it the exact same as always. Iwata LPH 400 gun with regulator and water trap at the gun, 20 PSI with 3 turns out on the knob and medium fan.
I have sanded it all the way down and started over and still the same problem 5 times! I even got to the point that I just went to do single stage and give the guy his money back since I am repainting it orange in the fall (if he even lets me now that I am taking so long) so I figured "hell, I will do single stage, give him money back and tell him that when we do the correct color then I will do it all over again". Layed the SPI SS down and SAME THING!
The primer nor base coat did this, only clear. It bubbles AS SOON as it hits the panel. I dont know what to do. I've tried everything from switching paint to new clear and activators, etc. Only thing that is old is my reducer which is about 1 year old and was opened but sealed correctly. I have no clue what to do here. Any oppinions or help is greatly appreciated!