Brian,
I wrote this a while back and saved it for this very reason.
Cleaning a Siphon-feed airbrush
I like to spray out the airbrush at higher pressures and use 50 psi myself, but if yours only puts out 20-30 then just use as much pressure as you can.
Dump the excess paint out and wipe the cup with a paper towel or rag.
Fill the cup about ½-¾ of the way with cleaner and then take an old paintbrush and wipe around inside the cup and down in the bottom of the cup around the needle with it to break loose the paint particles. Just dab it into the needle area in the bottom of the cup and it cleans very well.
I like a flat paintbrush about 3/8” wide, but you can use what you want. Just make sure the paintbrush is not one of those real cheap ones that the hairs fall out of, as you don’t want the hair getting into the airbrush and possibly causing problems down the road.
After that, spray the cleaner out of the airbrush.
You can now look into the cup to see how well you cleaned it.
If you see paint particles around the bottom of the cup still, then add a few drops of cleaner to the cup and dab the paintbrush into that area to break it loose, and fill the cup up about ½ way again with cleaner, wipe around in the cup with the paintbrush again and spray that out.
Wipe the inside of the cup with a soft rag or paper towel to clean any paint on the sides of the cup that may still be there. An old cotton T-shirt works good for this.
If you still see any residual paint particles, then once again dab the paintbrush around inside the cup with a few drops of cleaner in the bottom of the cup.
Fill the cup halfway with cleaner once more and hold a rag over the end of the airbrush to stop air from coming out of the tip. Push down on the trigger and pull back slowly and you will bubbles in the color cup as you are back flushing the airbrush. If you use high pressures to clean like I do then be careful doing this because if you have lacquer or other toxic cleaners in the cup and you pull the trigger back too far, it can shoot the cleaner up out of the cup and possibly into your eyes. That is why I say to pull the trigger back slowly until you get a pretty good amount of bubbles coming back into the cup. Do this for maybe 5 seconds or so and then look to see if any paint particles have appeared in the cup. Sometimes you will see paint particles, and sometimes you don’t, but I mention this just to let you see that back flushing can clean areas that just spraying out the airbrush can sometimes miss.
If there were very little paint particles in the cup from back flushing, then spray that cleaner out, fill the cup about ¼ way once more with cleaner and spray that out.
Remove the color cup, turn the airbrush over and clean inside the siphon-tube opening with a cotton swab soaked in thinner or cleaner for your paint type.
Also clean the siphon tube of the color cup with a pipe cleaner or brush soaked in thinner.
After it is good and clean then put the cup back into the airbrush and fill the cup ¾ of the way with filtered or distilled water for acrylics or thinner for enamels and spray that all out.
You can fill it about ½ way once more if you like and spray that out also, but if it seems clean enough it is not necessary.
Some people like to then just spray air through the airbrush for several seconds to dry out the insides, but that is up to you. Sometimes I do it and sometimes I don’t.
Now wipe the inside of the cup out with a rag, wipe any paint off the outside of the airbrush and you are done.
About every 4 or 5 times of using the airbrush I will take the needle out after cleaning the airbrush and wipe it off with a rag with some thinner on it to get any paint that may have not gotten cleaned quite well enough in previous cleanings. I then apply Badger Needle Juice or Medea Super Lube to the needle to help eliminate tip dry and keep paint from adhering to the needle. I also like a drop on the trigger to make it smoother as well as putting a drop on my finger and rubbing it around inside the color cup to make paint removal easier when cleaning.
These two products do not affect paint at all and are safe with enamels, lacquers, acrylics, and urethanes.
Every airbrush expert I know does not recommend disassembly to clean it each time and I agree.
Disassembling the airbrush each time is not necessary and I don’t personally recommend it because the potential of damaging the needle, tip, needle bearing, and other parts increases each time you take it apart. Some people feel it is better to take it apart each time and give it a thorough cleaning, and you have to make that decision yourself.
I hope this is helpful
Mike