What's causing my pimples?

C

Cirkitdude

I've sprayed things for many years, but new to BC/CC systems. I seek expert advice as to what's causing my clear coat pimples (see pics). Setup: garage paint booth (not cleanest in the world), cheap guns (yes, I know, I'm only as good as my tools, but I want to understand/master technique first), 6.8 SCFM compressor (but it was keeping up with me), water filters both ends of the hose. Had no problems with epoxy primer (as primer and as a sealer), 2k primer, base coat... all layed down beautifully. Here's my top coat sequence (after all the priming and leveling)... one coat of SPI red epoxy primer reduced 20% as a sealer. Next day, 2 coats Wanda BC... looked great. Next day, 1 coat SPI universal clear (gun inlet pressure at 20 PSI)... seemed to go on nicely but I noticed a LOT of overspray so decided to back off to 15 PSI for 2nd coat. Waited exactly 30 mins (per perfect paint job writeup)... sprayed 2nd coat at 15 PSI. Turned fans off immediately. Several hours later, close inspection shows the pimples (along with a bit of orange peel).

So, here is my theory (please experts correct me):

-- Orange peel due to a bit too much material... but not bad for my first try. Is the correction to up the inlet pressure to 20 PSI or to reduce volume delivery on the gun? Or perhaps modify my speed/distance technique? This I think I can fix, cause I've dealt with it before and licked it by being careful in material buildup... but the pressure thing I'm unsure about.

-- Pimples. These are very small (the pics are a tight zoom and deceptive)... look like needle pricks. They appear all over. Is this solvent pop? Or perhaps moisture in the line? Or dust? This I have no idea how to tackle, cause I don't know what causing it.

I intend to color sand and apply another coat, but want to know what went wrong so I know what to try to improve upon for the 3rd coat.

Thanks for the advice.
P.S. I love SPI products and their great phone advice and service. Have had a blast working with their epoxy and 2k primers.
 
Jim is correct from what I see. A quick wetsand/buff will get rid if that no problem. Everybody gets them some worse but it is nothing to worry about as long as it isn't an off color speck that shows when buffed.
 
Thanks gentlemen... feel much better now. This is 2 coats of universal clear... so wet sand out the orange peel and the dust (400 grit) and then another 2 coats?
 
Thanks gentlemen... feel much better now. This is 2 coats of universal clear... so wet sand out the orange peel and the dust (400 grit) and then another 2 coats?
 
That would work but with just two coats, I would say 800 would be first choice.
 
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