Bill in IL

Well-known Member
I am in the middle of painting my trailer. I have noticed that I have lots of water in my compressed air. What can I do about it without a large
desiccant or refridgerated dryer. I am not a pro painter just looking to get rid of most of the water.

Current setup is 60 gallon upright in remote building short air whip to underground line (steel pipe) for about 70 feet where it meets a filter/water
separator then hose from there. It's July in Illinois and disgustingly humid. I did drain the air tank yesterday probably go check it again but it
does not get drained daily like it should.
 
Your underground line is probably full of water if it's the lowest point. Depends what size it is on how to dry it out.
 
I think Greg is right that you have water in the underground line. I have my main line on a steady incline for close to sixty feet. The idea is the air will cool down in that stretch releasing the water and with the incline the water will drain back into the tank
 
I have thought about that any good ideas of how to get it out. Add a full port valve at the end of the pipe and blow it out? Do I need more pipe at the compressor to cool the air before going underground?
 
Your filter dryer is not working as it should or you have some much water in the lines and in the compressor tank it is being over powder. Have you drained your tank lately?? Tank need to be drain from time to time
 
The underground air line is really not a good idea, to likely to collect water without good way to drain it out. The ground will also be colder, so it makes a natural condenser.

Can you run an above ground hose from compressor to where you want to paint for now.
 
You really need to add an air dyer before the underground to get the dew point of the air down below the ground temperature.
 
What has worked reasonably well for me is a couple of 6 foot lengths of black pipe with a cheap water separator installed at the bottom.

Air supply enters at top to a 1/2 inch black pipe then goes down to a 90 and into the separator at the bottom then back up through a 1 inch black pipe which is then reduced to connect the coupler.
The larger pipe and gravity are your friend.
I run an second separator right at my pressure pot and do not have any water issues.
 
Run an above ground hose and see if you still have the problem.

I agree with others that your underground pipe is probably a natural condenser.
 
Do you think he will get condensation in the underground pipe just by the nature of going underground? Or should the air dryer take all the moisture out before it gets there?
 
I would try to blow it out at first, then hook a shop vac to it and let run 24 hours on a dry day. This will help get the pipe to air temp reducing condensation and the airflow for a long time will dry out what didn't get blown out. In theory it will work lol. Unless you can apply heat to the air going through to help evaporate the water.
 
It should reduce the condensation in the pipe if the air dryer gets the air dewpoint below the ground temperature, but there will be a small amount no matter what. That is why lines are sloped with drain taps. Most industrial air systems maintain a dewpoint of at least -50, and I have seen -90 commonly. I would think a dual chamber dryer would be best, doubt a coalescing trap would suffice.
 
I just did some research on air dryers.

The canister air dyers will get to 20 degree dew point below line temperature.
The refrigerated dryers will get 38 to 50 degree dew point
The dessicant dryers will get -50 to -100 degree dew point.

So, it appears to me that the underground line is a problem unless you would put a desiccant dryer in front of it.

I would just run a line on the ground and go from there.
 
By canister dryer do you mean water separator/filter type? After reading suggestions I think I am going to add pipe at the compressor. I was once told to use 1.5 inch copper out of the compressor in an uphill arrangement I think I will do something like that. Otherwise the trailer is painted and looks good nuff for now even with a little water.

My line below ground is 1/2 inch steel and for now have no plans of abandoning it just hope to make it work better.

Anyone use those toilet paper dryers?
 
A cheap way to remove moisture is coil up 100 ft of are hose inside freezer and put your dryer there too. Position dryer vertically. ' Cooling air should remove moisture on hot days. I used old refrigerator to make mine. If you want it dryer, take air that you cooled and send it through a toilet paper filter. It will work.
 
You mentioned that you have a filter/water separator in the system. Is it a manual drain, or one that automatically purges? If so, is it purging correctly?
 
Bubba sure is full of good ideas. There is a freezer right next to the air compressor but I think the wife may not appreciate dry air as much as I do.
 
I have an air dryer salvaged from a semi that I use when painting and sand blasting. Have never had a moisture problem after it.
 
With the small underground line, that is always going to be holding water, and anytime there is a demand for air, it is going to carry a surge of water with the air that overwhelms the water separator.

The easiest solution would be to plumb in a trap ahead of the separator. That can be a vertical length of large diameter pipe connected to a tee ahead of the trap so the water will tend to drop into the trap instead of going into the separator.

Then install a drain valve (preferably an automatic timed solenoid type) in the bottom of the trap. If you go with the automatic type, you can also connect it to the separator drain.
 
I used an old ice box for my dryer. The old kind that was not frost free. Drilled a hole in side of freezer side missing the old aluminum evaporator. Used one of the drain holes in evaporator to run the air hose out. Put a very large dryer in refrig section along with cold adult drinks. We drained the filter everytime we got something to drink, especially in the summer.

At the time, 40 years ago, NAPA sold similar devices that cooled the air, around $2k.

I took 28x44x12 old garage that original owner used to work on his semis and turned it into a hobby body shop for a tenant and myself.
Not sure where we got the TP filter. Back then TP filters were also used as aftermarket oil filters. My hobby shop is now rented as a storage unit, but I still have air system, the dryers, 5 hp compressor and TP filter. Used old galvanized water pipes with drop legs to have air in different locations in shop. Refrig died, I sent it to the recycler.

I really enjoy making something out of nothing. Now what's wrong with being CHEAP??? Yes, it was BUBBA's idea.
 
Autobody supply stores have a small screw on water filter that you can attach right before your gun. About the size of a tennis ball.That will catch the final water spits and mist before your gun. If you have a LOT of water you need a dryer as described below.
 



As others have said... I have underground lines buried between all my building and they all collect water... SO... I run a 20 foot section of hose up high, over a ladder and then down to a air filter/dryer,, the bigger the filter/dryer, the better as a large area, will reduce the air speed and allow the moisture to settle in the dryer.. then run a hose out of the dryer over the top of the ladder again out the the sprayer. small hose and high volocity will always carry moisture and even generate some... The large dryer at the low point will naturally allow the water to condense and fall to the bottom.

Even better is to take an old air tank and put two quick connections on it and run air in and out as described above... at the location near the painting or work again with hoses run over a ladder to the tank... AGain, this will naturally condense MOST of the water. This will work well enough for most painting,,, but a small filter at the gun will do the rest.

If you do lots of painting, the underground lines will start drying out some, but not totally... due to colder ground temps.
 
Problem is you are pumping air through water, basically adding water to the air. need to find a way to remove the water in lines underground.
 
Underground lines will do that. You need a valve at a low point to purge the water from the lines. You need a filter specific to auto body use.
 
I put a separate tank close to where I am painting. I hook my hose coming from the compressor tank to the bottom and take the air to the gun from the top. In this kind of weather I let the compressor tank bleed out the bottom enough to keep the tank empty of water. The second tank has to be large enough that you are using only a portion of the air so the water can stay on the bottom. My tank is a 30 gallon. In still air water mist collects together to make droplets which collects together into drops settling to the bottom.

In running Doral cigarette filters on a 4.5 second cycle with air ejection on six machines water in the air was a big problem. At the time money was not available for an air dryer to handle the volume of air needed to get the parts out of six molds. The molding room was 100 X 50 feet and to get the amount of dead air needed I hung and welded 4 inch pipe in a loop around the molding room using 200 feet of pipe. I welded in 2 inch saddles for each press and ran two inch pipe within a two feet of the floor with a ball valve. I teed off 5 feet from the floor to run the air to the mold using a short piece of 3/4 hose to the mold. We never had a water problem running 24/6 . I used 4 inches of fall in the 85 foot 4" pipe run with a 2 inch auto drain where I brought a 6" pipe in from the compressor at the low end. RJ Reynolds Doral filters was run this way for about 10 years without water in the air problems.
 
For those that do not remember the Doral filter from the 1970's this is what it was. What we run was one stem that made six cigarette filters.

DB1050-vi.jpg
 
I work with industrial air systems at work and they have a refrigeration unit in line. Only trouble is when the blasted auto dump valve gets stuck and water gets into all of the machines! The coil of copper or spare air hose in the fridge sounds great just as long as there is a water drain before it comes out of there. At the lowest point possible. The dryer the air the better! The harbor freight screw on dryers "red plastic tennis ball size" work fine as long as you change it EVERY spray gun fill up. Be on the safe side, they a cheep enough!
 
Ihave used ,for quite a few years, one of 'dem gas-line filters, sorta like the ones that go between the gas tank and the carburetor of a BRIGGS engine on your lawn mower.

When it has filtered out the oil and bad wet air, the paint gun will just be starved of supply air.

Time to get another filter outta the SPRAY CABINET supplies.

Get one real large and paint the whole project at one time.

1/4 inch in and out. Be sure of the arrow showing whick way the gas goes.

Or simply install a large refrigeration filter/dryer in the line that goes from the spray gun to the regulator.

Hope this helps.

John, PA
 
If the weather is especially humid you shouldn't be painting. This is usually the only time there is a lot of water in the air. Still, I paint professionally and all I do is make sure the tank stays drained and I don't get enough water in the air to hurt anything. I don't even use a water trap.
 
Its a single state machine. I got the trailer painted and looks good nuff for me. It did seem thought that when I was using the spray gun I saw
no water coming through, it was only with the blowgun. Must be the the higher flow rates overwhelming the water separator.

I still do wish to make some upgrades at the compressor...... Someday.
 

Bill, you have a super air dryer there, you just need to make a way to empty it. Would it be possible to dig a sump at the point where it turns up, with a piece of culvert pipe on end as a wall, and tee a drain off down in the sump?
 

Bill, I have a refrigerant dryer at my dad's place you can use anytime. I got it when I was an intern at Quincy Compressor, had a shipment come in with damaged sheetmetal and was cheaper to scrap than repair.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top