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Gordon Campbell
02-06-2002, 11:17 PM
I have a 5hp belt driven air compressor that I have water problems with when I paint or sand blast.
Would anyone know if an air dryer would solve the problem, and what size unit would I need?
Thank You,
Gordon

Thrud
02-07-2002, 01:12 AM
Gordon,

If you are spray painting (cars in particular) a water separator as well as a good air filter should be looked at. Drain your tank every once in a while or buy an automatic water dump for it. DeVibliss, Binks, or an autobody wholesale outlet should be able to supply what you need.

Dave

SGW
02-07-2002, 08:07 AM
I don't know a lot about this, but:

Just a regular air filter will help. It should be near the end of your air line, not at the tank, so the water vapor has a chance to condense as much as it will before it gets to the filter.

Travers Tool ( www.travers.com (http://www.travers.com) ) sells a mechanical device that's specifically supposed to remove water, but it's a couple hundred bucks. Get a copy of their catalog -- it's free.

You can also buy air dryers that are basically refrigeration units, that condense the vapor in the air so it can be extracted. Those are fairly expensive too.

rwellerj
02-07-2002, 05:49 PM
Gordon

I was always told that you should have at least 50' of pipe running between your compressor and your connection for your flexible air hose to allow the heated air from the compressor to cool. As it cools, the moisture condenses.

In my shop, I have air pipe running up from the compressor and around the shop at ceiling height, and then have vertical runs coming down to bench level with quick disconnects for the flexible air hoses. These vertical pipes each continue down for about a foot below each quick disconnect, with a ball valve installed. This allows any water that condenses to collect in the bottom of the vertical pipe and be drained off without entering the flexible hose.

If you are trying to run flexible hose directly from your compressor, even running the air through a moisture trap, you are almost certainly going to continue to be plagued with water due to condensation from the cooling of the warm air.

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Russ

bob
02-07-2002, 07:26 PM
I had the same problem until I installed a heat exchanger between my compressor and the tank. Now the water condenses in the exchanger and drips into the tank, instead of flowing into the tank as water vapor. Once the water is in the tank in non-vapor form, it can be taken out manually or by the automatic water release valve. I would still suggest a water separator in-line as an extra measure.

JCHannum
02-07-2002, 08:44 PM
Yes, an air drier will help your problem. They are sized by the CFM output of the compressor, and they are expensive.

It would seem to me, that if none of the above suggestions solve the problem, it would not be too difficult to make a refrigerated drier out of a refrigerator. You just need a large (50 ft would be plenty) of about 1/2" copper tubing inside the unit, an expansion tank, and a water separator to drain the condensate.

Refrigerators are cheap at garage sales, etc., and have other uses. Good excuse to equip the shop with one.