i have a Sears moisture trap on my compressor. its clear so you can see if it gets too full. problem is, i've never seen a drop in it, yet i can get several ounces of dirty water out of the petcock on the bottom of the tank about once a month. i live in the southeast. is there supposed to be some kind of absorbent in the trap? i dont have a lot of problems with moisture in my airbrush, but some clearcoats do go on milky, then clear up as they dry.
Return to Beginners Category Menu
Bet your clear coats are poly which is notorious for the milky look in humid areas. Go to the epoxy gloss and the problem disappears.
Use a slower drying thinner or reducer in humid weather.
When air is compressed it is heated as it expands it cools condensing out the water which drops out into your tank. Keep the tank drained like you are doing, what you don't want is water in your air lines. A pretty fair homemade water separator is to take a 3 foot piece of 3" or larger PVC schedule 80 pipe. Fill it with bronze wool and install end caps for an air inlet and outlet, and a water drain. Have the air enter the bottom of the separator, where it re-expands and cools more condensing water. The bronze wool proves a surface area and heat synch for the water to condense on. Works very well for little invested.
If you are truely getting moisture past your trap,you might possibly have it connected direct to your compressor.In order for them to perform properly there should be at least 25 foot of hose between your compressor and your moisture trap.A air compressor is just a big air pump that compresses and compacts into a holding tank.If the atmospheric air is laiden with moisture it is fed through the compressor.As the compressor runs the friction builds up heat and heats the air that is going through the compressor.Hot air can hold more moisture than cold air.As the air moves through the holding tank and down your hose it begins to cool.As it cools the moisture saturated air cannot hold all the moisture and it begins to condensate in your hose and holding tank.If you are not geting moisture past your trap then you humidity might be so high that it is geting trapped behind your finish.It can get trapped behind your finish when you are using a real fast drying finish like laquer.Then George and Rick are right.You can help eliminate it by using a slower drying product or use a slower drying thinner or retarder.
There isn't much to add to the fine threads you have received in response to your post. The moisture that is effecting your finish is probably microscopic beads that form by condensation of the surface of the fish. Condensate can form when the surface temperature is just a few tenths of a degree warmer or cooler than ambient air. Moving the fish from one area in the shop to another can cause condensate to form, just as breathing on a mirror in an otherwise warm bathroom causes fogging. The degree and size of the droplets may be invisible to the naked eye, but the result is visible in the cloudiness of your clear coat.
The distance a water trap is from the compressor has some significant value, but that distance depends on volume, diameter of line, kind of compressor, and other factors. I use an inline filter trap here in the swamp where moisture removed is measured in quarts, not ounces.....LOL (See instructions for building below.)
It is raining in your tank as the moist air is compressed, the water cannot be compressed, so the water vapor leaves the gases as precipitation at some point, just as overloaded atmospheres rain on the planet.....it is just a much smaller storm. Of course the compressed air does have the ability to retain a great amount of moisture and the trap is designed to eliminate that.
The best trap I have used is the one on my Mako compressor and it is attached directly to the unit. The mako utilizes an internal cooling fan for the top of the compressor unit.
Badger makes a handy little in-line trap for under thirty dollars. A quality in-line trap can be made for less with standard plumbing pipe, a couple of reducing nipples and correct sized (1/8") hose fittings. Here's how.
Simply use an eighteen inch section of 1/2 inch galvanized plumbing that is threaded on both ends. Attach 1/2 inch to 1/8 inch pipe reducers to each end. Attach 1/8 inch pipe nipples on each reducer and install in-line between the airbrush hose and the air supply. Here's the kicker!....Unscrew one end and stuff the pipe full of the most absorbant material known to mankind - tampax or other feminine tampons... Change tampons as often as necessary (usually when they become so saturated they no longer function, thus restricting air flow).........They do hold a hell of a lot of water......LOL.
And, by the way, BUY YOUR OWN! The little lady probably would prefer that. You ladies: Just buy additionals.
See ya