Water in the air line...!?

[tshort]

I've been running a Campbell-Hausfield filter in the line since I started; it allegedly is a water separator / remover as well. However, the air line seems to be generating a ton of water at the tool end. Dunno if some of this is condensation as the air cools, but I'm wondering if there is something else I could / should put in the line to remove water. The filter has condensation in the "jar" but never any measurable water. I hate to spend all this money on tools only to have them get soaked every time I use them. The compressor always has a lot of water in it when I drain the tank at the end of the day. The humidity in the house is 35-40%, I guess I could lower that but I keep it there for comfort in the winter.

Any thoughts?

Thanks
Thomas

[hngrflyr]

The only way to take the water out of your compressed air is to refrigerate it to below it's dew point. I made a poor mans air drier by introducing a coil of 1/2" copper tubing between the compressor and the air tank. I put the coil outside and ran a lawn sprinkler on it, then cracked the drain for the air tank just enough to take care of the condensed water coming in. That was the end of water at my paint gun.

[captain_john]

Yes, you will have water in the line whenever you compress air. The water condenses when the air becomes hot from compression.

This is why I got a 60 gallon compressor. When I paint, I leave the compressor off and use the cool air in the the tank for my painting job.

Hngrflyr is right. If you place a good sized coil between the tank and your water separator it will serve as a heat exchanger. This should be fairly large. A few sections of baseboard heat will work quite well. This will cool the air, separate the water from the air, be trapped in the water collector and be nice and dry at your point of use.

CJ

[tshort]

Yeah, I expected some water in the line due to compression - I just thought the filter would take care of it. Short of building a condenser, is there anything else I can do?
Or, more importantly, is this even something I should worry about as far as how it might affect my tools? I noticed it most on the die grinder, my hand was wet from the exhaust when I was done.

Thomas

[hngrflyr]

I tried using the coil between the air tank and the water trap. It was winter and the air was wet. The water trap was filling up so fast I had to watch it all the time. Installing the coil between the compressor and the tank did the trick. It enabled me to use the drain cock in the tank to remove the condensed water. The water trap stayed dry after that. If I remember right, my coil was a 10' length of 1/2" copper tubing.
It's been a long time since that happening. It was when I was painting my Cessna 120, in 1981.

[captain_john]

Yeah, I expected some water in the line due to compression - I just thought the filter would take care of it. Short of building a condenser, is there anything else I can do?
Or, more importantly, is this even something I should worry about as far as how it might affect my tools? I noticed it most on the die grinder, my hand was wet from the exhaust when I was done.

Thomas

It is a function of physics. Pretty much, the length of the coil is to give the condensation time to form. When you have a short hose, the condensation is forming in your tool. When the tool gets "waterlogged" it loses power and spits all over the place. The more powerful the tool, the compressor runs, the more water can build up. If you are running a high CFM air motor, like a die grinder or drill, expect alot of water.

Put the water sep after your coil.

How much coil (baseboard heat) you need depends on alot of variables, humidity, run time and size of your holding tank.

Oil your tools daily, if you like them.

CJ

[Don P.]

I live in Florida where the humidity is usually above 80%. When I worked in a shop that used a compressor all day, we left the Water sep petcock open a hair so that it was always blowing some goo out. I have a seperate air tank for increased volume. It's an old Natural gas tank probably 100gal. plumbed in after my compressor with a water sep on it. The compressor also has it's own sep. This give the air time to cool and settle. I painted my 73 Corvette which turned out perfect until the last minute when a drop of sweat from my respirator landed slightly off center of the emblem on the nose,AAAGGGG. I tried to do a repair and put 6 coats of base back on but it still showed thru the next morning when the sun hit it. Then had to repair again. Now I put a athletic wrist band over the exhaust side of my Respirator to absorb any errant drops. Don.

[hngrflyr]

I'm a retired industrial maintenance technician. I was recently helping a friend trouble shoot a machine that uses several pneumatic solenoid valves. It turned out the solenoid valves had failed due to water in the air system. He didn't want to use my poor mans air drier, but we did locate a small commercially produced refrigeration type air drier in the McMaster-Carr Catalog. It will dry 10 cubic feet per minute, and cost something just over $500. The air comes out cold and dry. We don't get one drop in the water trap. After $1000 to replace and protect the air controls, his machine is happy again.

[Spike]

Thanx for the info Don. Its amazing that a drop of perspiration could do that!!

-- Spike

[bmurrish]

I was running my 2 stage oil lubricatd compressor last night for the first time. I ran it for about 30 minutes.. When I was finished I opened the drain plug expecting to see some water come out, but there was nothing but air. I do live in Colorado where it is fairly dry. I do not have a water seperator on it yet. What is going on here? Do different types of compressors produce different amount of water?

[captain_john]

Depends on relative temp/humidity, duration of operation, demand and length of hose.

You explained a low humidity, short duration low demand and no hose situation. That is least likely to condensate water.

Come again when you really work that thing!

CJ

[bmurrish]

I just got back from Bills, opps I mean Lowes. I picked up a Campbell-Hausfield in-line air filter and oil lubricator. I gotta come up with a set-up to mount them to the wall and have it so I can quick disconnect the lubricator if I want to paint. If anyone has done this and has pics, please post them here or email to me. I also picked up a variable speed dremel tool with 75 acessories. Need more tools, arr arr arr!!!!

[captain_john]

I installed a "T" after my filter/regulator but before my lubricator explicitly for painting.

It is a simple thing to do. A few valves makes it easy to shut off unused pneumatic lines.



Not a good picture, but I had it already uploaded. I have the setup along the wall so I can dial in whatever suits my needs.

Lemme see about taking a better pic for you tomorrow.

CJ

[jim_geo]

OK I’ve had to deal with this stuff for almost 30 years. So here goes. Starting with the Physics of what is happening. Free air contains water vapor we all know it as humidity. Anyone that has placed their hand on a compressor while it’s running or shortly after knows they get hot, VERY hot. This happens because when you start mashing air molecules together the space between the molecules becomes smaller and they begin to collide. That causes heat caused by friction. The act of compressing air does not cause water to condense in our tanks in fact it encourages water to stay put as a vapor. When compressed air is stored in a bottle it contains energy because we have in fact added energy to it. One way of looking at is that we change the form of the electricity from the wall plug and it is now stored as wind energy in our tank. When we open the valve releasing the air to a standard atmosphere the compressed air looses energy that energy loss is in the form of heat loss, thereby encouraging water to condense and form water droplets. If we were able to stand inside our pressure vessel we could watch a cloud form around us as the pressure dropped. This pressure drop is exactly how refrigeration happens in our kitchens.

Dealing with the water that forms is always a problem. My solution is this. I hate draining my tank so I remove the drain valve and make that my main tank air line connection. I regulate my air pressure with a wall mounted regulator but that’s another story. My main air line runs into about 20’ of half inch copper tube that is coiled in a 55 gallon drum filled with water this is otherwise known as a condenser. After that the air goes through a centrifugal water trap. I empty that trap at least once a month during the winter and once a week during the summer. Using this system I never forget to purge my pressure tank since it automatically happens every time I use a tool. My air stays amazingly dry. I also use U bends equip with drain valves at my hose connections. I rarely get any water from my hose connection sites unless I have forgotten to drain my centrifugal water trap. One thing to note is a little water in your tools isn’t going to kill them but a little bit of water in your spray gun is going to wreck an otherwise great paint job.

[captain_john]

Bill, check this out:

I did it for you and others.

http://www.rivetbangers.com/cgi-php/for ... =2758#2758

CJ

[Don P-Factor]

OK, lots of great info on this site. Two more... try to always use a dedicated air line for only painting ie... don't use lines that have previously been used with the pre-oiler. Residual oil may exist. Also figure your line loss pressure for the amount of line used. It's been awhile but I think its 1lb loss for every 10ft of line. I always had a pressure guage at the gun too. Teflon cups are great for clean up. Pressure pots are cool, but a pain for clean up. Sorry I got carried away. Good luck, Don.