Hello all,
today I have been spraying some colour with my airbrush. I have a small compressor with a moisture trap and pressure regulation device and no tank, and usually operate it in warm days when I can stand in the open air.
Today it's raining and it's rather cold, and I noticed the airbrush started spitting water drops along with the colour. I disconnected it from the air supply and noticed that water droplets came from the compressor.
This issue already happened to me, so I didn't worry, let the compressor cool down and restarted it a couple of hours ago. Same result. Now the compressor is stowed in its box with a protective cellophane bag. I'll see what happens in the next few days and with different weather conditions.
Maybe the water droplets came out because the climate is quite humid here, and the lower temperature allowed the water to condensate, making the moisture trap useless when the compressor gets hot because of the difference between its temperature and the air's.
Has anybody ever experienced a similar issue?
Any solution to advise? Maybe a further water trap will help?
Thanks and have a nice day.

Hi Giacomo,

You could be getting condensation from the warm engine/piston and cool moist air. Or your moisture trap may not be working. Does any water ever collect in the bottom of it? Or you could be getting moisture in the hose when the pressure drops. If you own an Iwata or Grex airbrush, Iwata makes a pistol grip moisture filter that attaches between your hose and airbrush that will certainly solve the problem.

Thanks Matthew, I also thought it could be a condensation problem. My compressor gets hot anytime I use it and these days the temperature has lowered, plus it's been raining so the difference in the temperature definitely caused the water to condense.
The moisture trap, which has a pressure gauge and regulator as well, has always worked well, I could always see drops of water and vapor when the pressure raises, although I've never used it enough time for the water to collect on the bottom of the tank itself.
Carrying out some research, I noticed that this seems to be a regula issue with bad weather (so far, I used my AB only during summer days) and I'll definitely get a further moisture trap (not an Iwata original, maybe a cheaper one) as it seems to allow the airbrush to be used in any weather condition

Kepp the mosture trap as close to the airbrush as possible. (use a secondary hose between it & the tank) like:
Comressor---hose--moisture trap/regulator--hose--airbrush.

The air not cooling off enough will keep moisture in it longer.

Make sure to drain the tank & moisture trap regularly.

Thanks for the advice!
I've been spraying some air (no paint) so far, and the problem did not show up. Yesterday it was quite colder than today, so I think condensation was the real problem. I'll get an in-line moisture trap and another hose in the next following days and will keep you updated.

Good evening gentlemen,
I have been looking for a moisture trap but didn't have time to go to the modelling shops, so I've taken a look around the web and found this
http://www.luckymodel.com/scale.aspx?item_no=SX-2SXFIL-01A

It's three times cheaper than the Iwata genuine trap and of course I'd go for this one. Do you think it can be plugged to an Iwata airbrush? Silly question, but it will come from the opposite side of the world and I cannot try it up with my airbrush!