Expert: Ellen Choate - 8/15/2007

Question
Hello Ellen

I bought a new airbrush and the problem I had was that the trigger began to stay down which meant I couldn't stop the air flow. I took it back to the shop and they gave me an other one. I have the same problem with this one. It sticks straight away even though I have cleaned it. Am I supposed to put some sort of oil or grease on the piston? It says nothing about this in the instructions.

Thank you for your attention.
Regards, Alan.

Answer
Hi, Alan.  What kind of airbrush do you have, not that it makes that much difference.  I have noticed this problem more with my Iwata than I did with the Paasches I've used.  It confounded me when it first happened, too.  I went so far as to disassemble the air valve and clean that.  It solved the problem in that instance, but it's not fun at all, getting that teeny little spring compressed and the tiny little nut back in there.  Besides, I doubt that's your problem with a new brush.  
Iwata sells a lube that I find a little viscous for my taste.  It seems to gum up the works rather than loosen things.  I like Blue Juice valve oil, sold at music stores for brass instrument valves.  Don't use WD-40 as it can degrade the itty bitty rubber gaskets in the air valve.  Speaking of which, it could be that the gasket is a little tight and will loosen up with some manipulation.
The most likely thing, though is a little paint down in there. Try cleaning it gently down the air valve, make sure you don't leave pipe cleaner fuzzies in there, and squeeze a couple drops of valve oil down it.  Let me know if this solves your problem.  A new brush shouldn't do this.