What's the best device for getting compressed air super dry?

[robroy]

Hi!

I'm planning to apply Rust Bullet with a paint gun this weekend, and I've read that Rust Bullet hates moisture.

I already have an air drier from Sears installed in my air line but plenty of moisture gets past it; I can tell because I see moisture coming out of the tip of my sandblaster sometimes, and it doesn't seem to be oil for the tools (since it evaporates right away).

Does anybody know of a good solution for getting super dry air?

Thanks very much!
-Robroy

[71PA_Highboy]

It all depends on 'How much and How dry'?

HF sells a refrigerated air dryer... work great, but lots of money.

You can put a couple dryers inline, the farther from the compressor the better, so the air can cool down and drop the moisture out.

Once you have done that, one of the disposable paper in-line style on the input to the gun should finish things off.

I wouldn't worry about a little bit of moisture... the humidity will add some no matter what you do, you are just looking to minimize the air there.

HTH,

Eric

[robroy]

Okay, that sounds like good advice.

$400 is a lot of cash for something that I may only use twice per decade (the hard core air dryer).

I think I'll take your advice and attach a second air dryer in line and try to find a third small filter to install before the paint gun.

The guy I spoke to at Rust Bullet this morning said the air needed to be *totally* dry, but it's a little hard to believe this considering they're selling it to shade tree mechanic folks to use on their old vehicles.

Thanks!
-Robroy

[71PA_Highboy]

That's funny...

Right now ambient air in my shop is about 80% humidity... just blowing the paint thru that will pick up water.

one other thought, if you have an extra length of copper tubing, you can put that somewhere in the line, submerge it in icewater, then put a dryer after that, you will also cause more of the humidity to condensate and the dryer will be even more efficient.

His point should have been 'no water droplets in the spray' dry, not 'Totally' dry...

Unless his comment was: 'Totally, dude'.


r/

eric

[flyboy2610]

About the only way to get air 'totally' dry is to superheat it.
Otherwise, it will always contain a small percentage of moisture.

[price2757]

took me a bit to find it, in this thread:
http://www.fordification.com/forum/view ... hp?t=13431
The 2nd one down has a link to an article Keith did for a magazine on air compressors. It includes a way to plumb them to help get the moisture out of your lines. I haven't done it yet (need the compressor 1st) but I will be setting up mine like this.

[bumpside]

This is a poor mans air dryer. It will work fine for limited air use, like painting.

Make a coil of copper tubing the diameter of a container. It should also be about 3/4 the depth of the container. The bigger the better. 20 ro 30 gallon. Connect the air inlet to the upper part of the copper coil. and the outlet to the bottom of the coil. At the outlet of the copper coil install a good air filter/ water seperator. Then connect your air hose to the filter outlet. Fill the container with water and ice. You now have a poor man's air dryer.
When the hot compressed air goes through the coil in the cold water, it condenses the water vapor to liquid water, and the filter seperator removes the liquid water. You may want to leave the drain on the filter open just a little unless it has an auto drain in it.

[HOWDY69]

So I am getting ready to set up my new blasting cabinet and I may also try to learn how to shoot paint. My existing compressed air plumbing is just a hose straight off the filter and I get water dripping from my air tools. I have read the posts and Keith’s article about running piping around the garage with drops and whatnot to knock moisture out of the air. I have also talked to a co-worker who ran piping vertically up and down a wall several times to achieve the same thing. I would prefer to make the system out of off the shelf iron pipe fittings and standard pipe lengths and be able to assemble it on the floor and then bolt it to the wall. What are your thoughts on a vertical system versus the one on Keith’s diagram?

[BobbyFord]

There's a DeVilbiss air filter/dryer in the Summit catalog on sale for $159.95, has the filter cartridges.

[HOWDY69]

There's a DeVilbiss air filter/dryer in the Summit catalog on sale for $159.95, has the filter cartridges.

Thanks for the heads-up on the filter on sale at Summit. I guess what I am looking for is piping arrangements folks have used to get some of the water to condense before it gets to the final filter. Keith’s diagram has a lot of tricky angles that would be tough to build from standard iron pipe fittings. That is why I was thinking about running pipe up and down the wall several times with a sump and bleed valve at the bottom of each run. I was just wondering what other folks had done and how it worked.

This is a poor mans air dryer. It will work fine for limited air use, like painting.....

I like the coiled copper idea for painting but am not sure I would want to buy ice every time I used the blasting cabinet. Although I suppose cool water from a garden hose would work well enough for blasting.

[Whateverman]

in the powdercoating shop at the slave labour camp...i mean my place of employment ,we use 2 water separators,one for every 50ft of airline.. the second of which is actually a separator for a heavy truck airbrake system... and an air dryer setup just before the hookups for the spraygun