Maybe y’all can give me a hand with a new mystery problem with my airbrush. I suddenly am splattering my paint, comes out in a mist and then suddenly, splatches and spots. Never had this problem before. Using Pollyscale paints, at about 20psi. The brush is clean - i have quadruple checked that. The paint is thinned to the 25%/75% mixture that Pollyscale calls for. I think with blue glass cleaner, sometimes with distilled water.
I use a single action Paasche airbrush, a pretty simple creature.
I’m baffled. I can’t figure this out. Anyone ever run into a sudden problem like this, and any diagnosis or suggestions that might help me?
You didn’t say that you screened the paint. Before I pour any paint into the bottle I pour it thru a piece of womens stocking. It removes any clumps that might be in there. Now it only takes a micro clump of it to clog the paint. You might not be able to see it.
Make sure that ALL the very small rubber O-Rings are on.
As said above, make sure your hose isn’t kinked (even a little bit)
This once happened to me, and the cause turned out to be a very small piece of solid pigment had lodged itself in the gun (it was poly scale). Ever since then, i screen the paint to prevent a similar recurrence.
Also, does your paasche use a needle (i have an Aztec which has the needle in the tip)? My dad has an old badger airbrush, and one time the needle got bent, ever so slightly. This caused a slight disturbance in the paint/air muxture that caused drops to form on one side of the needle, and splatter the finish.
I have had this happen when painting shutters using a full size air gun on a humid day. Worked great until the air in the hose had been used then splatter. Cured with a moisture trap. Theoretically an airbrush could do the same.
I do filter the paint, have a Badger screen in the jar. Using the proper size (largest) needle.
Hmmm… Will have to check the moisture trap. Sounds like that might be the culprit. Never was an issue before, but will check on that. I did switch air brushing locations, now brush in my garage. Maybe it’s more humid there.
Whilw you are at it, drain the tank as well. There should be some kind of drain plug/petcock on the bottom of the tank. Do this outside in the lawn. The rusty water you get out of the tank will stain anything it gets on.
Sometimes when I’ve had this problem its because the paint didn’t like the thinner. “Blue glass cleaner” isn’t paint thinner and may not be the exact same formula from batch to batch or brand to brand. I used old Plly S thinner on Polly scale paint and it got blotchy, spattered paint that clogged the nozzle every couple of minutes. Cleaned everything out and changed thinners and no problem.
Dave, I’ll check that too. I think I have some Testors all-brand acrylic thinner here somewhere. I was just using the glass cleaner because it always worked well for me before. But like you said, maybe it’s not consistent.
Gonna give the brush another go tonight, with all these thoughts in mind.
I don’t know exactly what your Paasche looks like, but on some brushes paint can build up inside the tip, then come out and splatter. Some brushes use a crown cap to prevent this, but you can also just wipe the tip occasionally.
At the risk of sounding like I work for a paint company, I also don’t recommend using any thinner that the company doesn’t recommend. Paint chemistry is funny stuff, and it doesn’t take much to throw it off.
I don’t know exactly what your Paasche looks like, but on some brushes paint can build up inside the tip, then come out and splatter. Some brushes use a crown cap to prevent this, but you can also just wipe the tip occasionally.
At the risk of sounding like I work for a paint company, I also don’t recommend using any thinner that the company doesn’t recommend. Paint chemistry is funny stuff, and it doesn’t take much to throw it off.
somehow when I read this thread i missed the part about the glass cleaner. I have heard several guys recomend windshield washer fluid to thin paint with (acrylics). The majority of the makeup of this is Alcohol. I have tried to use straight 91% alcohol to thin with before with mixed results. Sometimes it works Ok and other times I would find the paint congealing in the cup/jar. I am not sure why this happens but, I have since stayed away from using alcohol to thin with. Now I just use the water I get from my de-humidifyer or in absence of that distilled water.
I’ve also had good luck thinning Pollyscale and Future Floor Polish with vodka. Its basically just water and ethanol (one for the airbrush, one for me, one for the airbrush, one for me…). I know Future Floor Polish is an acrylic and reacts badly to ammonia, so if the glass cleaner had ammonia in it it might cause a reaction. I have also had different types of alchols cause the acrylic paints to curdle.