This past weekend, I ran into a strange problem airbrushing enamels for the first time. Here's the problem:

When I start the airbrush flow, the AB "spits" some thick dots of paint in addition to the fine mist it's supposed to. I noticed that if I triggered ever so gently, I could (mostly) get this to stop. But I haven't noticed this action in sessions past.

The paint was AK Earth Effects, and I tried both straight out of the bottle and with some minor thinning. Same effect with both.

I started playing around a bit and noticed that if I "flicked" the trigger back and forth without applying air pressure, it would spit the same way... almost like the seal wasn't working properly.

I broke down the airbrush and cleaned it like mad, reassembled, and had the same results.

I then cleaned it again and ran some water through, just to see if maybe it was the paint I was using... same spitting problem.

I inspected the AB needle very closely and all *seems* to be OK there... but maybe not?

Anyone have any ideas on what's going on?

Thanks!

PS: I'm not sure if this is related, but the spraying seemed to get stuck way, way too much, requiring me to open up the valve and blow out some paint to get things flowing again.

Even using a brush, I think AK's stuff pretty heavily. Never tried airbrushing it.

But the usual "my airbrush isn't working" questions apply:

-type of AB?
-what psi?
-what are you using as a thinner?

AB is a Badger Krome, PSI varied, but I had it down around 12psi and up to 18psi... didn't seem to make a difference.

Thinning was done with AK Mineral spirits.

I don't think the "too thick" was the problem since I was recreating the same results with pure water too.

Have you cleaned and oiled the plunger? Another possibility is that the paint is not mixing well. It may be a bad bottle.

Spitting airbrush is usually a clogged or dirty airbrush.

If you spray both acrylics and enamels through the same airbrush, this is a common occurrence unless you strip it down in between for each type of chemical.

If I had to guess you sprayed your acrylic base coat, then switch to spraying the Earth Effects, which might also have some pigments in it for texture and may cause even more issues. Chances are good acrylic residue remained and reacted to the enamel and gummed up the AB.

After I switched to a multi-airbrush setup, I haven't had any clogging issues again. I can't remember the last time actually. I have an AB for Tamiya paints, one for Vallejo/Lifecolor, and one for enamels/filters/washes etc.

If I don't bend a needle, I'm good with regular cleaning routines.

So I recommend a very thorough breakdown and cleaning, ensure everything is clean and dry and free from any other solvents and residues. Then see if that works.

HTH,

Mike
http://www.faceook.com/RinaldiStudio

pull the whole brush apart. thoroughly clean the brush parts, needle and especially the hard to reach places, like where the needle runs through the color cup and the nozzle inside, those things are tough on the new Badger brushes. Good luck.

Since you had the same issues with plain water, I'll rule out to thick of a mixture, although my AK Earth Effects is quite a thin mixture as is. Another non issue is high humidity which causes spitting and water drops.

The only other thing it can be is some contamination in the brush itself. This is one reason why I prefer to use an external mix system: the Paasche 1-H series. Super easy & quick to clean and maintain.

Joel

do you have a moisture separator ?