Compressor spits out moisture

[Jerry Evans]

Hi, I have just purchased a 36gallon 6hp compressor from sears and have a question...the other day I started it up and was using it with a few truck tools and I was getting water out of the hose after it was running awhile..so I went and bought a glass vile type moisture filter for it thinking it would capture the moisture and I would drain it from time to time...well today I used it again and still water out the hose and tools and No water in the vile...I want to be able to use this for painting cabs for the shop and other things but until I get rid of the water I cant...I put the vile between the compressor and the hose...what am I doing wrong...thank you

[David DeCristoforo]

You are not doing anything wrong. Drain the compressor frequently. The water trap should catch most of the condensation but there is no way to get completely dry air out of the end of the hose short of hooking up a refrigerated after dryer. There are better moisture traps you could try, but none of them are really going to "dry" the air.

[Don Selke]

Jerry:
Do not know where you are located but humidity plays a part in how much moisture you are getting into your compressor tank. As previously stated, drain the tank frequently and purchse a better moisture filter. You will not get all the moisture out but it should trap most of it. As David said, you would need a refrigerated after dryer to get it all.

[Jerry Evans]

thank you for such quick replies....I live in florida and it is really hot right now...but shouldnt there be some condensation in the filter vile I bought..if not I might as well take it off and just drain the tank then...thank you

[David DeCristoforo]

The "filter" may not trap moisture. The air will simply pass through it and the moisture will condense in the hose. If you need to get moisture out for finishing, you would be much better off to get a good moisture filter like this:

http://www.tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=9036&utm_source=googlebase&utm_medium=cse&utm_term=DEVDAD500&utm_campaign=googlebase_18u

or this:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200343662_200343662

or this:

http://www.mactools.com/Product/tabid/120/productid/318228/variantid/308987/Default.aspx

and mount it as close to your finishing pot as possible. Avoid long hose runs between the filter and your pot or gun. My moisture trap is mounted right on my paint pot.

[Scott T Smith]

thank you for such quick replies....I live in florida and it is really hot right now...but shouldnt there be some condensation in the filter vile I bought..if not I might as well take it off and just drain the tank then...thank you

Jerry, as air is compressed it heats up, and the warmer that air is the more moisture that it will hold. Moisture condenses out of air as the air cools. Thus, if your compressor is running fairly constantly, the air coming out of the tank is still warm and a water filter mounted next to the tank won't catch most of it. Instead, as the air cools inside your air lines the moisture then condenses out of the air.

If you increase your air storage (ie add an additional tank), the compressor will cycle less often and it will give the air more time to cool down in the tank; trapping the water there.

The best thing to do is to drain the tank frequently. Alternatively, purchase a larger tank compressor that does not have to run continuously for your end use.

[Michael Pyron]

moisture traps need to be downline from the compressor by at least 30'..this is because as you are driving the motor its heating up the air and it takes a while for it to cool down and condense (like 30')...when I'm concerned about moisture in the lines I run a 30' hose up in the air and at the last bit of length run it down to the traps (I have both a water and an oil trap as I have an oil lubricated compressor) then run my working hose off of that....its definitely worth it to use 3/8" hose for the run to the traps as the smaller the hose the greater the friction and the more air flow loss due to said friction...definitely drain your compressor often, and especially right before you are doing work where you are super concerned about moisture (like spraying a finish)...

the air hose lead is a cheap and easy alternative to doing the same routine with cast iron pipe....

[David Freed]

To be able to drain your tank quickly and easily, get one of these. http://www.ryderfleetproducts.com/cgi-bin/ryderfp/products/srm/oid/51680/erm/product_detail.jsp?utm_source=googlebase&utm_medium=search&utm_campaign=product

Every time you walk by your compressor, you can pull the cable for 4 or 5 seconds. I put a pan under my drain so the water wouldn't go on the floor.

[David DeCristoforo]

"I put a pan under my drain so the water wouldn't go on the floor."

That would not work for me... that's how I clean my floor...;)

[Jerry Evans]

I am using a 50ft 3/8 hose...do you think that is too long....and you think I should put the moisture vile at the end of the hose next to the tool or paint cup and not the beginning and then drain the tank often ..I can not warrant the expense of one of those driers at this time since what I am doing is only for me and my family not a customer...anything else I may need to know to get a good start...thank you

[David DeCristoforo]

That would be your best bet. Put the filter as far away from the compressor as possible with as short a run as practical between the filter and your spray rig.

[Paul Atkins]

Here's a 'whatif'. What if you put an inline coil of copper tubing in your shop refrigerator with a drain on it? (Yeah, I know, what is a shop refrigerator.)

[David Freed]

I put a pan under my drain so the water wouldn't go on the floor.
That would not work for me... that's how I clean my floor...;)

You wash the floor in your woodshop?

[David Freed]

Here's a 'whatif'. What if you put an inline coil of copper tubing in your shop refrigerator with a drain on it? (Yeah, I know, what is a shop refrigerator.)

That sounds like a "you might be a redneck if you do this" idea. Also sounds like something I would try. I bet it would work too. :D

[Chris Parks]

Put a portable air bottle in the fridge. They are fairly cheap and it will have a drain on it.

[Marty Paulus]

Here is what I am planning on doing with my air system: I am going to run some copper tubing along the wall behind my compressor and put the filter inline after that. That will allow the air to cool prior to the filtration and from what I have learned that is the key to clean, dry air. One think to keep in mind in your case is the airlines you have been using are now all contaminated. You will have to either put a filter inline before the tool/sprayer or buy new airlines.

[johnny means]

Your best, cheapest bet is to dehumidify your work space.

The fact is that when yoou pump your moist warm florida air into a compressor tank, you are instantly cooling it past the dew level. This is going too create condensation in your system no matter what. Once the moisture is in there, it's going to be in your air too. I don't live in Florida, but I've been there enough to know we're probably not talking about amounts of moisture that can be handled with little filters or hose trickery. If an expensive dryer is out of the question, starting with dry air is the only real solution. My solution was a HVLP turbine system (gobs of warm dry air), but thats not cheap either.

[Chris Parks]

You don't need an expensive drier, that is for industry. An old fridge, a portable air bottle and you will dry as much air as you can use. The whole lot would not cost a huge amount of money.

[Kevin L. Pauba]

Here's a cool home-made intercooler:

http://www.dune-buggy.com/webs/Off-Road_Buggies/todd_kirkwood/compressor.html

[William M Johnson]

I would advise you to put up a couple of 1/2" copper U shaped loops on the wall with a quick connect at the bottom of each. Also mount your final quick connect ( the one your hose attaches to) as high as possible. I have been using this setup for a couple of years with excellent results. I have painted cars and shot many gallons of lacquer and sealer without ever having a fisheye due to water.

You will still need to drain the tank and the bottom of the Us periodically.

[Josiah Bartlett]

I run a coiled hose through a bucket full of cold water when I paint, and then run a water separator after that. Then I use a small regulator followed by a disposable desiccant filter at the gun and it works really well. For just running air tools I don't worry about water- I just keep the tools well oiled.

[David DeCristoforo]

"Here's a cool home-made intercooler:..."

OK. I like that! Also JB's cold water bucket. The only problem I would have with that is that in the summer around where I live, the water will not stay cold for very long!

[Tom Veatch]

Your best, cheapest bet is to dehumidify your work space....

You'll have to dehumidify down to below 10% Relative Humidity (RH) to prevent 100% RH and condensation in the storage tank, and well below 10% RH to prevent condensation in the air withdrawn from the tank when it cools on expansion.

Ambient air at 10% RH and 15 Pounds per Square Inch Absolute (psia) compressed to 135 Pounds per Square Inch Gauge (150 psia) is a 10 to 1 compression ratio. The partial pressure of the water vapor at ambient conditions above 10% RH will be at or above saturation pressure after a 10 to 1 compression and cooling back to ambient temperature.

Greater than a 10% RH ambient will guarantee that the air in your storage tank is saturated with water vapor and a pool of liquid water is at the bottom of the tank - assuming, of course, that the storage tank is pressurized to 135 psig or greater.

[Josiah Bartlett]

"Here's a cool home-made intercooler:..."

OK. I like that! Also JB's cold water bucket. The only problem I would have with that is that in the summer around where I live, the water will not stay cold for very long!

You can put the bucket outside and run a steady trickle of water through it if necessary. You just need to cool the air below the dew point. It doesn't take much.

[Jerry Evans]

thanks for all the great replies...I am going to try a few and I will get back to you with the outcome so someone else may benefit..thanks again

[Chris Parks]

Your best, cheapest bet is to dehumidify your work space.

This won't work for at least one reason and two if the compressor is outside. You have to replace the used air so the inflow is going to have to be de-humidified fairly quickly and as the workshop is in a tropical climate it won't be air tight. Besides that how much is a big de-humidifier worth, not exactly cheap I would have thought.

[mickey cassiba]

That sounds like a "you might be a redneck if you do this" idea. Also sounds like something I would try. I bet it would work too. :D
I wouldn't do it...probably warm up the beer. Kidding! I salvaged a little "kegger" and that sounds just like what it was made to do. No-one needs a whole keg of beer anyway!
Mick