How to Dry Compressed Air

-

dibbons

Well-Known Member
Joined
Nov 6, 2009
Messages
5,692
Reaction score
3,755
Location
La Paz, B.C.S., Mexico
We open the drain located in the bottom of the tank of the Dewalt compressor all the time. However, when we want to dry something off with compressed air, we are still getting the parts all wet. What should we do, is there a water trap or filter recommended? This compressor is used in a body shop where my Formula S is being restored. I don't want to tell the owner what to do, but I don't want H2O mixed into my paint formula. Thank you.

Dewalt.jpg
 
There are in-line driers that you can put on the hose before attaching your air gun etc....
 
There is only two ways I know of to dry air

1....A dehumidifier, which is essentially a refrigeration unit which cools the air and condenses the moisture out and drains it off

2....Chemical dryers IE "dessiccant" which of course the active material must be changed to keep it effective
 
Water in the line is OK for an air gun, but you don't want any water in line when painting.
100_2695.JPG
There are in-line separators available. Also can use this little trick-see photo.
 
Put your compressor in the clothes drier... Then turn on the drier, then the compressor....

You will then have dry compressed air....
 
Put a inline dryer for now but you may want a regular dryer unit. I have one on my big shop compressor plus an auto blow down valve that open every 20 mins for 3 seconds and that helps a lot. They are cheap compared to paint supplies about 60.00 plus some plumbing
 
Air going in makes a big difference. Hot, humid air from outside is going to drop out a lot more water. So if you can pull air from an air conditioned space it should help. If you can do tubes like above on wall in a cool space it should ring out a lot more water. Thats all a refrigerated drier Really is.
 
There is only two ways I know of to dry air

1....A dehumidifier, which is essentially a refrigeration unit which cools the air and condenses the moisture out and drains it off

2....Chemical dryers IE "dessiccant" which of course the active material must be changed to keep it effective

I don't know why in hell someone would disagree, this is pretty much correct. Anything that cools the air is also under the heading of dehumidification.

Murry posted a photo of an elaborate trap. These help if they are cool enough. In a hot climate and a hot building, maybe not so much. YOU CAN also put a trap in a cooling bath like a garbage can or 55 gal drum, if you have the water to spare
 
When my old Craftsman compressor quit after 15 years or so I replaced it with a DeWalt as shown in the first post. I removed the compressor from the Craftsman tank and hooked the tank in series to the new DeWalt.
Most of the moisture is in the DeWalt tank, like serious water, and just a little mist in the 2nd tank. I run a few drop leg drains throughout the shop.
A cheap inline drier for the few time I spray anything.
 
Water in the line is OK for an air gun, but you don't want any water in line when painting. View attachment 1715565847 There are in-line separators available. Also can use this little trick-see photo.

I use the up and down method but I added valves at the bottom so I can crack open the valve every now and then to let the water out.

I have 5 runs that go 15 feet high then go to a spare tank and I added an extra run up the wall before I connected to the shops air piping.

I have no faith in having to add dryer material or changing filters. I went from pressurized water to very dry air. When I paint I have a dryer on the pressure regulator.

Cheap and never have to buy crap.
 
I have a bowl separator on mine at the output of the tank.

I also have a long-ish run like pot #4 but not as many courses, basically just up about 6 feet, across the shop, and down.
MUCH harder for the water to travel up, and if it does make it, when it comes down the other end, put your air fitting ABOVE the bottom end of the pipe and put a drain valve at the bottom.

I take it one step further by having a dedicated outlet connector for my paint gun that also has a regulator and small HF desiccant filter.

Low buck all the way and works great.
 
My compressor has an aftercooler on it and it makes a world of difference. Even on really humid days I rarely have any moisture at my air hose. The aftercooler lets the water fall out before it hits your air lines.
The automatic tank drain wont help the moisture problem. You need to force the air to cool down so the air condensates.

Quincy QT-7.5 Splash Lubricated Reciprocating Air Compressor with MAX Package — 7.5 HP, 230 Volt, 1 Phase, 80 Gallon Vertical, Model# 271C80VCBM | Northern Tool
 
We open the drain located in the bottom of the tank of the Dewalt compressor all the time. However, when we want to dry something off with compressed air, we are still getting the parts all wet. What should we do, is there a water trap or filter recommended? This compressor is used in a body shop where my Formula S is being restored. I don't want to tell the owner what to do, but I don't want H2O mixed into my paint formula. Thank you.

View attachment 1715565832
Had same trouble, was told I needed 25’ of steel/aluminum/copper tubing to cool air temp before going into water and oil filters. I looped 40’ of copper tubing and then went to filters. I already had the time release drain on tank. Now air is less then 100° when entering filter/separators and water can be removed. It took care of my issue. I still use an extra filter before my 25’ of painting hose and disposable filter at paint gun when painting as an extra precaution.
 
Remember to get rid of the moisture and use a dirt filter also. Make sure your compressor isn't pumping oil past the rings, that will goof up moisture, dirt traps, and auto-drains quickly. Use a manifold to drop the temperature, or a copper pipe arrangement like post 4.
 
-
Back
Top