Need help with drying air

[grillzy]

I recently purchased an ingersoll rand 80gal 7.5hp 2 stage compressor. This compressor is going to be used for painting. What do I need to dry the air properly? I did find this

http://www.kijiji.ca/v-power-tool/oa...ing/1197598172

which is about a 3hr drive from me. Will this dry the air from my compressor? Any help on this would be much appreciated.

[mongocanfly]

I know body shops have those larger air dryers..on mine I have a inline water separator at the compressor and added a small disposable separator at my gun..about 30 bucks for both..I'm no painter by any means but they work for me and our humidity usually runs around a 1000% around here..without a trap my air nozzle will constantly blow water out...with both seperators on I don't get any moisture..

[A1971Blazer]

If that unit works properly...get it...a refrigerated dryer is the only fool proof way to remove the moisture.....filters and separators will catch some but not 100%....you can add an intermediate air cooler(similar to a radiator) but with that small of a compressor you probably won't need it......the only thing I could see is the R12 freon is expensive if it needs charged....

[franken]

The only way to dry air is to cool it, then trap the water. Think of grains of sand sprinkled on a table. Now push the sand into 1/3 the space. More sand in one space, which is like compressing air 3:1. Same air, same water molecules, less space, more heat. Remove the heat, and the water molecules condense into water, which is heavier than air.
My opinion is that water should be able to collect a fewer places rather than more. The first is the tank--you need to drain water daily if you use the system daily. Just a few seconds from the bottom is good after things have cooled.
Now we come to the dryer... With cool air, a less expensive dryer system is possible.
No water should be allowed to accumulate in the lines. Long vertical and short horizontal runs with valves is brain dead. All water has to flow through the system, collect in the tank, trapped in the dryer, or go out the end. This is just common sense, but will be argued with.
Finally, it depends on your budget. Its a system--compressor, lines (not hoses), filters, dryers, regulator, hoses, and tools. People buy a compressor and think they're done. The compressor is a fraction of the cost of an air system. I spent years buying air tools before finding a compressor that could run them, and more time/money building the system between.

[A1971Blazer]

You can get an auto tank drain like this and set the frequency and duration for drain time.....that way you don't forget to drain it...


I've worn out so many piston compressors in my shop that I finally bit the bullet and got this unit.......25HP Ingersoll Rand rotary screw compressor with built in refrigerated dryer......100 CFM free air.....120 gallon receiver tank.

[B. W.]

I use a Devilbiss/Camair dryer (130525) $188.00 on Amazon. The filter/desiccant bag will last well over one paint job. I use it infrequently so I usually have to change it with every job. This is a "middle of the road" option, there are certainly better one but cost goes with them. I would not go cheap, when you are finally ready to lay down paint & you look at the cost/time involved to get there, you don't want moisture problems. (or the cost/time to re-prep after a problem). I'm not a painter but I do a fair amount of painting (does that make sense?)

Just as important as the dryer is plumbing the air lines properly, as said by others, you need to keep the tank drained & if the first run of pipe coming out of the tank goes straight up as high as you can get it, this will help cool the air & the moisture will drain back into the tank. Some painters recommend a minimum length of pipe between the tank & the gun, if space is limited you can just go up & down the wall with your pipe to make up distance (you must install drains at all "bottoms". I have about 50' between my tank & gun.

Bobby

the dryer in your link will do an excellent job, overkill (if that's possible)

[grillzy]

I am new to the compressed air thing other than small compressor for small air tools. a complete rotary unit with attached dryer would be nice but out of the air budget. I do have an electric auto drain on the bottom of the tank. Thanks for letting me know that air dryer will work. I am happy with overkill. Most of my en devours are like that.

[A1971Blazer]

Originally Posted by grillzy

I am new to the compressed air thing other than small compressor for small air tools. a complete rotary unit with attached dryer would be nice but out of the air budget. I do have an electric auto drain on the bottom of the tank. Thanks for letting me know that air dryer will work. I am happy with overkill. Most of my en devours are like that.

What you have will work just fine with that dryer...you will be amazed at how much water comes out especially on hot humid days....
The main reason I went with the big rotary is that all my CNC machines have air solenoids....water in the air supply will kill them quickly....I went through several piston compressors with dryers and they worked fine....but the air demand wore them out.....the last one had the pump replaced three or four times....finally just got tired of messing with it

[grillzy]

Originally Posted by A1971Blazer

What you have will work just fine with that dryer...you will be amazed at how much water comes out especially on hot humid days....
The main reason I went with the big rotary is that all my CNC machines have air solenoids....water in the air supply will kill them quickly....I went through several piston compressors with dryers and they worked fine....but the air demand wore them out.....the last one had the pump replaced three or four times....finally just got tired of messing with it

Good to know. This will only see a few paint jobs and then work its way into the woodshop for some air sanding. Got the same blue 72 Jimmy!

[cg285]

those dryers are not necessary if you plumb correctly. both my shop and home shop use black pipe. out of the compressor it goes to my max height avail then criss-crosses coming down the wall (angled slightly to drain down) which makes like a radiator to cool the air. at the bottom there is a large drum drip (9"x12" black pipe with drain), into the building and up with another drum drip (2") then angle up or down as nec to remaining outlets. each with a drum drip. at the shop i use reg/dryer followed by dessicant for the paint booth. at the house i use reg/dryer followed by a "motorguard m-60". i rarely even get water at the inside drum drips and i am in sunny, humid central florida

[Tom Vogel]

I've worn out so many piston compressors in my shop that I finally bit the bullet and got this unit.......25HP Ingersoll Rand rotary screw compressor with built in refrigerated dryer......100 CFM free air.....120 gallon receiver tank.
Attachment 1571758[/QUOTE]

And its sitting Outside??

[grillzy]

picked up the air dryer and he tossed in a nice filter.

[Cape Codder]

My hobby shop became a full time body shop for one about 15 years ago. I have my compressor mounted in the rear corner of the shop with black iron pipe running straight up to the attic. Then it has an uphill run about 20 feet to the front of the shop where it takes a 90% turn and runs straight 13' the the center between the overhad doors and drops straight down. I added a drop with a drain before the water seperater /filter. Most of the water condenses in the pipe and runs back to the compressor as it is downhill for 25 ft. I drain the tank once a month and get about a 1/2 gal. The drop drain gets opened about once a week and gets a frw tables spoons of water. I don't seem to have to drain the water seperater of filter more than twice a year. I very seldom ever notice any moisture in my air lines. The idead is to get the air cooled and water condensed before it gets to the hose. Running a hose straight from the tank is where you get water problems.

[grillzy]

thanks for the pictures. that helps alot

[A1971Blazer]

Originally Posted by Tom Vogel

I've worn out so many piston compressors in my shop that I finally bit the bullet and got this unit.......25HP Ingersoll Rand rotary screw compressor with built in refrigerated dryer......100 CFM free air.....120 gallon receiver tank.
Attachment 1571758

And its sitting Outside??[/QUOTE]

Heck no......that was when it was being installed...it's totally enclosed on the back of the building....

[Cape Codder]

I also think running the big pipe helps as with just a 3/8 air hose the air speed in the larger pipe doesn't force the moisture through the pipe but allows it to run back down to the tank. If you run small pipe to the hose the air will run just as fast as the air in the hose. I am not a scientist but just my thoughts.

[theastronaut]

Here's what I built for cheap and it works great. It chills the air so the moisture condenses and the water trap can catch it.

http://67-72chevytrucks.com/vboard/s...d.php?t=509229

[grillzy]

Originally Posted by theastronaut

Here's what I built for cheap and it works great. It chills the air so the moisture condenses and the water trap can catch it.

http://67-72chevytrucks.com/vboard/s...d.php?t=509229

No different than a still. We are doing the same thing.

[Dieselwrencher]

The still looks like a viable option too. That's a good idea.