Ty,
The small air compressors run very hard to make even a small sandblaster perform properly. When you have the compressor maxed out, it is hot, the compressed air is hot and this is compounded by a small tank. Even with a trap next to the compressor, the air is still too hot for the water to fall out of it. The secret is to somehow give the air time to cool below the dew point so the water can fall out and be trapped.
I have seen several suggestions in this forum. They ranged from a hose coiled inside a 5 gallon bucket filled with ice water to cool the air, to several long runs of iron pipe to help dissapate heat.
A 1/4" pipe will pass about 50 CFM at 150 psi, so don't worry too much about undersizing your filter. It should state a max capacity right on it.
No filter can pull water out of HOT air...this is the key, somehow, get the air to cool more. When you go to spray the finish on your rig, dry air is absolutely necessary. The small CFM requirement of the gun lends itself to the small disposable filters you can put inline ahead of it. This air can't be full of water here either, it must be almost dry..here is link to what I have been calling a filter, just so we are on the same page. Good luck.
http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?xi=xi&ItemId=1611777815&ccitem= Stuart
