Paint air dehydrator

Progress made on painting the new RV-8. So far it has gone well. Fuselage and wings are done, now waiting of a few warmer days to finish up the remaining pieces and parts.

As you that have painted a plane know, getting moisture out of the paint air is critical and not all that easy to do. I have three drains on the air system of copper pipes that alway run with an up slope. The final trap is in the attached photo. This is a simple thing to make, 50’ of tubing coiled in a Walmart plastic tube with water and a couple of jugs of ice floating in them. It is amazing how much water comes out of it. Air goes in the top of the coil, the drain is on the bottom of the PVC pipe - extending out of the tub, the hole sealed with flox. Note the air hose coming out of the tub and going into the paint booth also runs up hill.

This one is made with 3/8” aluminum tubing from ACS. Next time I’ll use copper tubing as the aluminum corrosion is fairly rapid if you let it sit in the water for days on end.

Carl

That's a really good idea! And much cheaper than a refrigerated air drier: https://www.harborfreight.com/compressed-air-dryer-40211.html

I use a cheap 50’ x 1/4” ID air hose from HF and put it a large cooler in loops laying flat. Then about 20# of bagged ice. The air is pre and post water trap filtered. I like the idea of using aluminum tubing better so will use that method next time.

Motor Guard

That's pretty cleaver. I've had pretty good success painting with inline dryers, but this is a terrific idea. The paints today compared to the paints of 30-40 years ago seem much more susceptible to oil in the lines from compressor by-pass. Activated Carbon Compressed Air Filters really work well for filtering out oil and other contaminants.

https://www.amazon.com/Motor-Guard-...ywords=motor+guard&qid=1604277520&s=hi&sr=1-5

?....aluminum corrosion , here is 2 cent idea, keep / use the water you drain out of you air system , and use it for your coolant water. Because the water you are getting out of your city / local water system. Has corrosive causing stuff / chemicals , in it..........
But the your, self built cooler is a , ( a really good idea! )
good job / good day / rick

HVLP?

Carl,

Are you using this setup with a compressor-fed HVLP gun, or an old fashioned conventional spray gun? I know there are also some hybrid models that are something in between. Just wondering if all the tubing results in a noticeable pressure drop when you start spraying?

Using a Harbor Freight HVLP gun with a regulator at the inlet of the gun set at 50psig (I tried the expensive guns but I find this one works best for me). The compressor regulator and second inline regulator are set for full pressure.

No issue with pressure at the gun.

Carl

You could probably get away with a coil of PEX in the ice water.

The poor heat conductivity of PEX won't matter if you have enough of it.