Airbrush problem with spray fading away

[mjs101]

When I airbrush, I am getting a good flow for two seconds and then less and less until I get to all air, no paint. I have dual action air brushes and both have the same behavior. If I pull the trigger all the way back, I get a lot of paint, sure, and this "solves" the problem so I end up pulsing the air brush trigger back and forth.

I am getting the same problem with different Vallejo paints, including Vallejo Polyurethane primer, Vallejo air, and Vallejo model color. I have tried thinning with vallejo airbrush thinner (clear), vallego thinner (transluance), and water. However, if I use pure water, no problem. I am spraying what I think is thinned enough paint, but maybe not. I am thinning the Polyurethane and Model Air a little bit, and the Model Color at least 1:1 if not more.

I don't think this is dry tip, although I am not certain.

I suspect it might be Regdab needle juice, since it has gummed up other parts of my trigger. I wish I had never purchased that crap. If so, it is way in the nozzle, and dried to the consistency of maybe wax. If that is the problem. Challenge is, the nozzle is so darned small I can't see in side it nor clean it well.

I have an Awata Revolution with the original .5mm nozzle and the parts from the eclipse line to install a 0.3mm nozzle (nozzle, needle, and the screw in the back.) I also have a Pasche LV with badly misused during my learning years. This has I think a 0.55mm mozzle and a 1.0mm nozzle.

 

[eyeayen]

It sounds like your nozzle is okay as you are getting the spray pattern initially and then it's going. So either you have something in the airbrush like a hair from your cleaning brush or there are bits in the paint, possibly old stock.

You should leave your nozzle out over night soaking in thinners (spray away airbrush cleaner in a little sealable jar is great) then you should be able to clean it with a brush in the morning (over a kitchen tissue, then if you drop it hopefully it won't roll too far) and then start again, it just sounds like the nozzle is getting blocked. I had the same issue recently when I was using some old createx paint through mine.

If you're using a 0.5 nozzle I'd say it's definitely contaminate in the paint as they are good for almost anything.

 

[mjs101]

Thanks, it is soaking now. After just ~90 minutes, there are threads or whiffs of stuff the looks a little like gel in the solution. Fingers crossed...

 

[eyeayen]

Has it worked ? You might need to get a brush and make sure it's completely clear. If you hold it up to the light you should be able to see if it's clear or not?

 

[mjs101]

Better. I am not certain I am at 100% yet. I mixed Vallejo air with 50% airbrush thinner, and the spray didn't fade out, although I think it was not 100% consistent, either. I am also running as a lower pressure than I normally run (18psi vs. 25psi or more). I am soaking it a bit more, this time with just with drops in the gravity feed bowl.

 

[eyeayen]

Low pressure won't always help as if you are using a higher pressure it's likely to pull through thicker paint, lower pressure not so much.

I don't like leaving anything to soak in the airbrush itself, I would rather disassemble it entirely and let the pieces soak. The reason for this, I always found it left some sort of residue which then needed soaking to get off. Also be careful what you're soaking it with if it's in contact with any of the rubber O rings in the airbrush as it can cause them to perish. I would always recommend replacing all O rings with Teflon ones as they last better and stand up to solvent very well.