Compressor Moisture

if you don't live in low humidity, you need a trap. compressing air make it hot and wet.

The drain plug doesn't expel moisture. It lets you drain any moisture that has accumulated in the compressor's reservoir tank, but the plug must be closed when you're actually using the compressor.

Yes, you need a moisture trap, unless you live someplace with near-zero humidity. Without one, you'll get drops of water being blown through the air hose every now and then, which can mess up your paint job.

snipped-for-privacy@sbcglobal.net (teem) wrote in :

Not entirely an answer to your question, but... According to a nearby airbrush specialist, moisture traps often don't work with compressors that have a very small air tank (like many cheap membrane compressors). With these compressors, the air doesn't cool down until it's in the air hose, so any condensation will occur after the moisture trap. Unless you use a long hose (5 m) with a moisture trap in the middle. As an alternative, you can do what I did: buy a long, transparent hose, and regularly check for condensation in the hose. Once water starts to accumulate, disconnect the airbrush and blow the water out of the hose.

With a larger compressor, the air will cool down inside the tank, allowing the moisture trap to do its work.

I utilize the tank valve, an inline water trap, and a room de-humidifier. I have had no problems with water blowing through my system.

The drain plug only drains the water that condenses while still in the tank. IT is important to drain this now and then. However, vapor still stays in air into hose, and can condense in hose. The water trap should be placed as close to where you use the airbrush as possible. I have a regulator/filter/trap unit mounted just above my workbench. It also contains the adapter to the small airbrush hose. In that location I can adjust pressure from bench without getting up and going to where the compressor is.

As most have recommended, use the moisture trap. I use two traps, one at the compressor and the other (a Paasche) about 5 inches from the connector to the airbrush itself. Trust me, you will cry if you have a nice finish going on and all of a sudden you have water splashed along with the paint - that happened to me, and that is why I use two traps. My compressor is probably older than you are, I got it it when my Dad passed away in 1977 and he already had it for about 10 years before that. It is an old Penncrest(spelling?) (when JC Penneys used to sell tools and the like), and it still blows about 20 to 25 psi. Don't forget to get an air pressure regulator also.

Cheers and happy modeling,

Ray Austin, TX ===

Excellent idea! Thanks for sharing. John D.

Forgot to mention that some of the guys in the club I belong to have Co2 tanks to power their airbrushes. The Co2 has no moisture, so that is one way to go. One caveat, the initial price of the tank is a bit pricey and then comes the filling the tank whenever you run out of gas - since I don't have one, I have no idea how many models can be painted with one tank.

Cheers and happy modeling,

Ray Austin, TX ===