Finish Looks Like A Golf Ball

[MarkPav]

Lately when I spray I get weird dimples through my paint. the surface looks like a golf ball effect. The sunken areas of the dimples are pretty much level with the previous coats, so when I sand level I am basically removing what I've just sprayed.

It looks like there's oil or something getting into my paint, but I installed a water/oil trap today and it didn't help at all. Maybe it's not working?

It doesn't seem to matter how the surface is prepared either, or even if it's not. It doesn't seem to matter whether I spray light or heavy, close or far. I don't get it.

Any ideas? There are some pics of some areas I spot-sprayed tonight, if that helps.

[mikhailgtrski]

The finishing experts here (I'm not one of them) might want to know:

-what are you spraying? (nitro, poly, etc.)

-what's the psi setting?

-was it contaminated before you installed the trap and could the hose and gun still be contaminated?

-what have you been using to wipe the body down?

-is this a refinish, and did it ever have silicone-based polish applied?

Sounds like fisheye, but I can't say for sure.

[oz tradie]

Looks like you've got a silicon reaction there.

Take it back to a flat surface, again. (that sucks)

Pretty much start over. But this time when you're laying on the first few coats,

apply what is called a 'dust coat'. If you have no contamination of your lines,

and you've applied and wiped off a degreaser just prior to tack ragging it, (b 4 spraying)

you should be relatively trouble free.

When I was working in a Panel shop (17 years of it, ouch) we had many minor silicon problems.

Some were as stupid as wiping things down with a rag contaminated with silicon polish

or armor-all. Or touching something similar then touching the item ready to be sprayed.

Worst case scenario was the air lines seeping in oil from the compressor.

Now, getting back to the dust coat.

The reason for the dust coats at the beginning are to basically seal off the item from anything

underneath which can re-contaminate.

A dust coat will seal and dry the item off quicker with less solvent biting into the bottom coat.

Doing the wet coats to begin with mean there are obviously a thicker coat of paint, with more wet thinners

incapsulated within, which in turn has a greater chance of biting in and causing you to tear your hair out later.

I hope this helps.

[Mattia]

Looks like orange peel. Playing with pressure settings, finish composition will help, but basically, you'll need to level-sand that out.

[MarkPav]

Thanks for the fast responses, guys!

To answer some questions:

I am spraying water-based Auto Air Color paint.

I'm almost positive it's not orange peel, although the photos might not clearly show that. It really just looks like the paint won't stick to certain areas as it goes on. In fact, some of it looks almost like a wall in a house that gets mold or mildrew on it.

I have a good HVLP gun and I've changed the PSI at the gun (it's 40 at the compressor), plus I've fiddled with all the other settings, but nothing helps. Before this started to happen I was getting nice smooth coats. This is the fourth coat to give me this problem now and I've been going crazy trying to figure it out.

The silicon diagnosis sounds the most likely. I had a bucket of clean rags I was using to wipe the body with before I used the tack rag, but I have a strong feeling that my father-in-law used a few to clean his car and then dumped them back in the bucket. I actually could smell some kinda armour-all-type smell on them, but I put it down to something else at the time.

Hmm. I understand about doing the dust coats, but should I still degrease the body first? If so, what can I use to degrease the body with that won't eat the water-based paint?

Edited May 20, 2006 by MarkPav

[oz tradie]

The contaminated rag scenario sounds the most likely.

40 psi sounds o.k, although you can take it to 35. ( I prefer 40 to 50 myself)

You mentioned that you noticed the silicon fish-eyes popping up on the fourth coat.

This can be compounded if there are quite a few coats applied in quicker succession than

would be recommended. Remembering that you want your previous coats to "flash off'

before you re-apply over the top. In essence, give a bit more time between coats for drying.

As far as a degreaser goes, I would consult the can or what have you, for a recommended product

for that particular brand. The products website could have data sheets in this area.

Always degrease before spraying. Even just to remove body oils from handling the item.

We used Prepsol which was perfect for Automotive applications but maybe not for yourself.

One more thing !!

If you notice these fish eyes appearing while spraying again, let it dry out for longer before

reapplying a dust coat over the affected area.

Again this is there to seal off and hopefully stave off further reactions from permeating future coats.

Then you should be able to reapply as a normal coat.

The normal reaction is to spray on heavy coats to try to bury it. This just makes it worse.

So , take your time and go lightly !!

Good luck with it and let me know how things go.

[MarkPav]

You mentioned that you noticed the silicon fish-eyes popping up on the fourth coat.

This can be compounded if there are quite a few coats applied in quicker succession than

would be recommended. Remembering that you want your previous coats to "flash off'

before you re-apply over the top. In essence, give a bit more time between coats for drying.

Me, rush things?

Actually, I had been taking it all slow and easy, but I messed up and had to strip it and start over (not the first time, either ) and so this time round I was playing catch-up.

Thanks again for the help! Hopefully, I'll get it right this time.

[MarkPav]

Ok, it's not the silicon. Long story short, I sprayed several different surfaces, used two different guns, and it is happening worse than ever. It seems to get worse each time. I used two different paints as well, although they were both the same brand.

What the heck could it be? I'm stumped. The only things that haven't changed are the compressor (which used to work fine) and the brand of paint. Guess I'll go try another brand of paint, but if that doesn't help I don't know what to do.

Any more ideas?

EDIT: I figured it out. It's the Auto Air Color paint. It fish-eyes all on its own, no matter what the surface and no matter how it's applied. It even did it when I smeared it on a piece of scrap with my fingers.

Edited May 20, 2006 by MarkPav

[Racer X]

Sounds like fisheyes. Had that problem on the last headstock I was trying to laquer clearcoat. Had to sand it all back down, and start over. Switched over to clear enamel, and didn't have a problem, after that. Dunno if it was the laquer, or surface contamination. I know I wiped the surface down, real well, prior to shooting, though.