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I'm having some trouble with my air quality that is becoming a problem when using my blasting booth and when painting, basically anything that requires the compressor to run fairly constantly. I have a small water trap at the outlet of the compressor but the air still contains moisture which is condensing in the air line. I've had to repaint some parts 2 or 3 times and it is really annoying me.
So, I'm looking for advice on what I can do to dry the air properly. I'm happy to spend maybe $500 to get it sorted, any advice?
I have an old steam or hot water unit heater. It has copper tubes with fins and a fan that would blow hot air into a room. Many of them have an 1 1/4" inlet and outlet. I have the fan wired to come on when the compressor comes on. Air in the top, air out the bottom with a tee and a long pipe or nipple to catch water, valve at bottom. The air running through cools and condenses and water gets trapped. You could get one new or used from a plumber or heating contractor. Dennis
I have a water trap on the paint gun and a small line dryer at the compressor. I'm really looking for a larger/better moisture filter that I can mount inline.
The three air filters are all clean but are not of the type that can be oiled.
I have an old steam or hot water unit heater. It has copper tubes with fins and a fan that would blow hot air into a room. Many of them have an 1 1/4" inlet and outlet. I have the fan wired to come on when the compressor comes on. Air in the top, air out the bottom with a tee and a long pipe or nipple to catch water, valve at bottom. The air running through cools and condenses and water gets trapped. You could get one new or used from a plumber or heating contractor. Dennis
That's not a bad idea, my only worry is whether the copper can safely take the 120psi that I'm producing.
This is my only dryer, as you are cooling the air, you're condensing the moisture out and it runs out the bottom caught in the drop pipe.
Factories with large air compressors have large air dryers like this. They're quite effective, what I'm using is just on a smaller scale. You really need to cool the air coming out of the compressor and by doing it you are removing moisture as well. Dennis
To properly function your water trap needs to be at least 25 feet away from the compressor via metal piping. The water trap can be right next to the compressor but it needs at least 25 feet of metal line between the compressor and the water trap. The metal line cools the heated compressed air which allows the water vapor to condense and be removed from the air. Plastic and non-metal lines will not allow the air to cool enough to condense the water vapor. So move your water trap as far away as possible, make a large back and forth pipe set up and mount your water trap at the end of it and you will be a lot better off.
I saw a tip one time that worked for me. On the line out of the compressor plumb in a 50' coil of copper tubing (the largest you can afford - I used 5/8") and place as much of the coil as you can in a tub of water. It cools the air down enough that it doesn't condensate nearly as much. With copper being expensive now it isn't a really cheap fix, but it worked for me.
These homemade coolers only work if you can drain them regularly, otherwise you are just filling the supply line with water. Make sure you are using a large enough water trap/separator and desiccant dryer designed for spray painting air supply and use a second desiccant dryer as close to the gun as possible. Also make sure you have a large enough supply reservoir. If you have less than 60 gallon tank and/or live in an area of high humidity buy another 40 gallon or larger tank and plumb it in series. Reduce the humidity of the incoming air to the compressor as much as possible. Finally the ultimate solution is a refrigerated drier. If you are needing to pump 120# pressure to your gun, you need to buy a new HVLP spray gun or a larger compressor.
Some good suggestions. Possibly a vertical back and forth pipe system with a port at the bottom of every loop, tied to a common drain. A bit over complicated maybe but it would work. I can't justfy a refrigerated drier, the cost is just too high for what is still a home workshop. I was thinking a dessicant drier when I started this thread, just really looking for makes and models that poeple have used successfully, all are definitely not created equal. I'm not giving my spray guns anywhere near 120, that's just the compressor output, I regulate the pressure down at the gun end as I will change pressure often during a spray job. Depending on which gun I'm using, what I'm painting and what product I'm spraying I'll be anywhere between 15 and 50 psi.
You could do a back and forth where the horizontal legs are angled like saw teeth so they drain Use a large enough diameter pipe. T the supply into the upper part of the drip leg.