I'm trying to figure out what went on when I sprayed base on my truck. In the attached pic, is that fisheye? What would cause that on clean masking paper? Leftover solvent in the gun?


background:
I was smoothing over a seam where a new roof was welded on, and had done filler/filler primer blocked/epoxy primer where I broke through the filler primer. I cleaned with lacquer cleaner on the panel each time before I shot filler primer/epoxy.

The epoxy primer went on dry, and I decided that I would just block everything and put a sealer coat before basecoat. I followed the instructions to a T for the sealer coat, and it went on smooth. I cleaned the gun and reassembled it, and mixed my basecoat. I wasted the 30 min as specified on the epoxy, then started my first coat of base. On the repair areas, the paint went on fine. On the areas that was sealer over the original paint, it went on like in the picture but worse. I freaked out a bit, pulled back and went back to the masking paper to do test shots (which made the spots in the pic), wiped up the paint (and sealer) in the areas that messed up (which was separated from the repair area by a body line), and then continued painting the panels since I was already committed (3 coats base, 3 coats clear).

So the repair areas actually turned out great (for a first timer), and the messed up areas I continued painting even though the subsurface was messed up, figuring that I could use it as a base to block from when I go to repair and that I needed to practice my form. It didn't have the "fisheye" look on any of the subsequent coats, and turned out better than it should have. Note the only areas that messed up were areas of original paint that were scuffed with 500 and sealed.

Products used:
Nason 2k filler primer (and matching activator)
Proform Epoxy primer (and matching activator and reducer)
Limco Supreme BC (and matching reducer and hardener)
5 Star Xtreme CC (and matching activator)

Here is the repair area, while it was still wet (second coat of clear, I think). I'm pretty proud of it, even though things went sideways during prime time.

Looks like some sort of contamination on the panel/masking paper.

If it was in the gun, it would've happened all through out the job.

You also shouldn't be using lacquer cleaner to clean a panel.

Perhaps the lacquer did not flash off enough in those certain areas?

Spraying a heavy coat like that for it to run may also have something to do with it.
Someone correct me if I'm wrong.

I've seen different materials do that if applied to thick. Just had it happen Tuesday with some epoxy primer.

Everybody, do yourself a favor.... take your lacquer thinner and mark GUN CLEANER ONLY it and quit using it to rub down panels with.... Modern lacquer thinners are mostly solvent reruns contaminated with all kinds of chemistry. When they collect and reprocess them from big industry they are at best run through simple sand filters which just catch the big stuff but don't address the other chemicals they may have picked up. The lacquer thinners from the big box hardware stores are the worst. Use proper wax and grease removers, auto quality tack rags, etc. And if you are going to use it to clean your guns I'd still tail up by running a good urethane reducer after that.

Use the right chemical for the right job. Makes sense to me.

DarrelK wrote:Everybody, do yourself a favor.... take your lacquer thinner and mark GUN CLEANER ONLY it and quit using it to rub down panels with....

Well said and exactly RIGHT!

OK, so the likely cause is from the thinner not flashing off from the sanded clear area and transmitting through the sealer, along with (maybe) thinner in the gun.

And I'll make note that I don't apply paint too thick. Also to get proper O&W cleaner.

Good tip on running the reducer through the gun. I normally disassemble and clean, then blow out the passages before letting the parts sit a while. When I have back to back products, I'll run some reducer through after to clean things out (or just use another gun that's cleaned and ready)

Thanks everyone!

When using anything but a quality automotive paint grade Wax and Grease remover, you run the risk of leaving a film residue behind. This is the same problem people have when using rust converters and metal prep solutions without properly neutralizing them.
Lacquer thinner, acetone, mineral spirits, etc. should not be used to wipe down metal just prior to painting it.

Yeah, people just don't realize how much the solvent industry has changed. When we used to be manufacturers of strippers back in the 1980s I would only buy "virgin" chemistry for our mixes but found out I could later buy reprocessed ingredients at 1/2 the price per pound and they were guaranteed to contain only minimal levels of other contaminants that really didn't affect our chemistry. It was only a few years of using those and the contaminant list not only grew but the quantities of them doubled and tripled. Back to virgin solvents we went and never used them again.
Since most wood refinishing hobbyists still wipe their stuff down with mineral spirits, lacquer thinners, naphtha, etc., we see fisheyes, distortion, and even non-drying oils, varnishes, lacquers, etc., quite commonly now. For those hobbyists we've had them all switching to the automotive wax and grease removers instead.
Saw a wood finishing chemist demo at a show swipe half of a panel with a big box store mineral spirits and then had everyone inspect the panel for "clean".......then he hit it with a black light.... it was a big smeary mess compared to the area left alone.