Dry The Air

[Air-Cooled Head]

A question for folks who use air-tools. I just had this discussion w/ a buddy last night. He sez I’m crazy.

The problem I have is water in my compressed air. I can only use an air tool a few minutes before the quick-connect at the tool end is slobbering all over the place. I have to drain the compressor every few minutes. I know this is because my rubber hose is connected directly to the compressor, and the condensate has no place to go, but to the tool. Bad.

So I’m telling my bud that I’m going to run steel pipe with a trap or 2, to remove moisture from the compressed air. He agrees with the concept, but says just use rubber hose. But I’d swear I read/heard somewhere that the steel pipe helps to cool the air and draw out the moisture, more so than rubber hose would.

What says the air tool using community? Does steel pipe help “dehumidify” compressed air, or would rubber hose be equally effective?
_________________
Everything known to man has been written.
Readers are Leaders!

[theKbStockpiler]

Do you have a drain on the tank slightly open so water can drain while you are using it? Unless you have a huge compressor and a long run of steel pipe, I think you will have to live with it. When it's really humid ,I have the same problem. I use a filter when painting and oil my tools a lot. Maybe you could hook up your compressor intake up to a dehumidifier so what does not go in, does not come out.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[buguy]

I would run a length of coiled up copper tube and then into a drain with a valve. What is happening is the compressed air is hot and is cooling as it heads toward the tool. When it cools it condensates. What you need to do is give the air more time to cool and form the droplets before making it to the tool. Copper will cool more quickly than steel (and it is semi flexable). So the water will either drain back into the tank, or into the drain you make. Either way and can be drained and you will have cleaner/dryer air. The 2 stage compressors are better for this reason. They run slower creating less heat. Surely you have one of those little oiless compressors that make a shit ton of heat and moisture. You can also use filters and dryers, but most are pricey.
So grab yourself 30ft of the coiled copper and have at it. It should work pretty well.

[Air-Cooled Head]

[buguy]

I understand. Its not always possible to have a 7hp 60 gallon $3000 compressor sitting in the corner. Just have to make the most of what we have.

[johndl58]

+1 on Buguys comment.

[c21darrel]

Keep an eye on craigs list...
I found my 3 year old 7hp, 220V 60 gallon compressor for $235 an an estate sale I stumbled upon in the neighborhood.
_________________
GhiaBuild
http://www.thesamba.com/vw/forum/viewtopic.php?t=481184
1967 DC build
https://www.thesamba.com/vw/forum/viewtopic.php?t=693583&highlight=67+dc
Stop dead photo links! Post your photos to The Samba Gallery!

[damac]

i went through this issue the hard way recently when trying to paint a car. i actually tried to paint a panel for my first time and got a couple fisheyes with crappy inline restricting harbor freight filters and figured i was good since i wasn't doing much.

same deal with the 50 foot rubber hose.

air tools like sander and blaster would work for a short while and spray water out the tool and completely was ruining the experience for me with all the time wasted.

i was trying to save $$$ and just did my best to rework the system.

we have about 40 feet of 3/4" pvc that goes up and makes loops up the wall with a few drain valves at the bottom turns. then i have a little jog to a nice wall 3 phase filtering system that isn't from harbor freight. then this goes into a toilet bowl type filter.

then i will run a 25 ft. hose for paint and tools with no filter on the end.

its 100+ out right now and yesterday we did a test and was pounding on a finishing sander for about a half an hour.

i could see droplets form and collect in first phase of wall filter and some in the second. i didn't check the toilet bowl.

never saw one drop of water after pounding on the sander and using an air hose which was a dramatic result for me!

just minutes after i was done we released the pressure in the lines and tablespoons worth of water came out of the ball valves, and some came out of the compressor itself!


i started this project trying to see if i could paint using a single stage and got a couple fisheyes. then i got a couple more. i was so bummed i grinded all my paint off each time and started over.

i think i was getting a drop or two of water with my hvlp gun which did make the compressor turn on and hope to try to paint again next week.

i was amazed that i could regulate the pressure better with the quality filtering system vs. the inline stuff which is very restrictive.

i am assuming the water is just a physics thing and nature of the beast so i learned the hard way.

i know metals transfer the water/vapor breakdown where as my rubber hose and pvc doesn't, and i still have a 25ft.

but i am hoping that with my system that the good filtering right before my soft hose is no different than a better designed system that also would have you plug a soft hose into a quick disconnect and use spray guns, etc.?

i noticed in some nice shops on youtube for example they aren't using those last step ball filters at the end of an hvlp gun to catch any droplets, so im guessing if you are filtering out at some point after a run my system will just have to work harder and collect more water?


this is a big problem for somebody new like me. i went from spending full days outside with the will to tackle this job to hating it within a month and stalled progress. between this and not having some of the proper tools and materials i have been disgusted at all the back and forth wasted time i have spent plus the mental and physical wear and tear.

sometimes you just need to get the proper setup going and spend some $$$.

one of the big things for me with my old 79 rabbit is using the blaster on seams and other areas and my air was getting wet in a minute and clumping everything up it was terrible. between stripping and panels and preparing some of these areas with blaster and da sander should have taken a day, has taken weeks.

[buguy]

Those little cheap filters on the paint guns are never a bad idea. Cheap insurance. Moisture and humidity suck for painting. Remember that when you paint its real easy to get fisheyes you you put the paint on too heavy with one coat, of sont let the paint flash for the proper time. Its the solvents getting trapped under the surface of the next coat and not having the time to escape. But of course, moisture in the line can do it too. Along with a million other things. Keep tire shine/WD-40/Armour All away from paint at all costs!

[eshan2]

I have a 3/4 inch dia 50 foot copper coil plumbed to my compressor. 3/4 black iron water pipe from the compressor to the coil. The coil is in a modified plastic chemical drum that is filled with water. A drain on the bottom of the tank and another for the coil and several more draining ports in the shop. Once inside the shop I used 3/4 schedule 40 pvc. No problems as long as all pieces inside the drum are copper or brass. On really humid days drop a bag of ice in the water with the coil.
_________________
I love the smell of nitro in the morning.
1963 Beetle currently under reconstruction.
Ernest.

[Air-Cooled Head]

[eshan2]

I have a Quincy Qt 7.5 compressor to start with. I started with what I thought was a decent 2 stage from sears 23 years ago. It was not adequate for air tool use. I can't imagine a single stage for anything but airing up tires and floats. Any way 3/4 inch black iron water pipe from the tank to the coil. Yes it is all outside. From the coil I used a 3/4 inch copper nipple out of the drum then back to black iron to the shop. I used a pvc union where the pipe enters the shop. The shop is done in pvc. For now. Going to change it all out this winter to proper air line. If you can put 3/8 on your tank or even 1/2 inch change it. 1/4 inch is too restrictive for supply. Your cfm is flow also check to see what your regulator flows. A small regulator can kill cfm also. You can put an automatic drain on a compressor for a little over $100.00 it plumbs in in the existing drain spot and rums on 110 volts.
_________________
I love the smell of nitro in the morning.
1963 Beetle currently under reconstruction.
Ernest.

[johndl58]

So, being someone that is about to experiment with painting, will the little drying canister be sufficient to keep water out of my gun? Should I add a extra length of hose? I'll be doing one or two pieces at a time, and if those come out OK, I'll then be doing the body. I'm borrowing a compressor so I don't really have the option of building an elaborate water trap.

[raygreenwood]

This whole problem is very common.

First if the ambient humidity is high.....you are compressing water. The water separator only separates "live" condensed water. Water in vapor form.......not visible vapor.....but entrained vapor......is still in the compressed air.

If you have a smallish compressor....and using the air almost as fast as you compress it into the tank.....there is very little time for any extra moisture to condense on the tank walls....and it usually wont anyway.....because on a heavily used small compressor....the tank is too warm to have an effective dew point temperature to condense water vapor from the compressed air.

Now....if actual the outside temperature. ....read that as air line hose temperature...... is lower than the temp of of the tank and the compressed air.....the air in the hose can quickly start shedding water. This is why you need a water seperator at the tail end of the long run of hose. Then a short whip hose and a final small dessicant filter at the paint gun if you are painting.

I had this same problem yesterday. Running a needle scaler.....about 80F outside with humidity at about 65-70%.....needle scaler slobbering everywhere......very little water in separator....virtually no water in the tank.....lines full of water.

This is a very big problem as well in cheap factories and shops I have been in. They have a short term manufacturing problem so instead of running new black iron or copper supply tubing over the ceiling. ...they run a 3/4" air hose.... ......so.....condensed water pools in the low spots where the hose hangs between rafters.....as it gets full....it pushes a gob of water forward. When several of the low spots in a row get full....it effectively hydro locks the hose and the hose explodes...spraying nasty smelling water everywhere and causing a masive air leak 30 feet off the ground. Happens every time. Ray

[johndl58]

Thanks ray

[raygreenwood]

The above problems I mentioned...are why if you have a long run from the compressor.....say over about 25-30 feet.....and your garage/shop is noot climate controlled....its worthwhile to run a "plenum" pipe down a wall with bayonet spigots at intervals to keep the actual hose runs short.

The really good advantage of this is that you can do it cheap or less than cheap. You can do this with a length of schedule 40 or 80 PVC pipe. But put it at a very slight slope....and add a ball drip valve at the end.

Metal is better...but the PVC will work well. The object is to give the air...someplace cooler than the compressor...that is NOT your final delivery air hose...to condense its water in.

The condensed water will pool at the end of the pipe away from the outlet spigots. At night, when you shut the system down and pressure is relieved on the pipe...the ball drip valve will allow the water to drain away into a catch cup or simply on the floor.

A ball drip valve is a simpple screw in device that looks like this
https://www.dixonvalve.com/product/SBDV50

It is...as the name says....simply a ball bearing on a ground seat. When air or water pressure is on it...it seals against the seat....no leakage. When pressure is relieved....gravity allows the water behind it to drain out around the ball.
Ray

[modok]

Our shop compressor is 10 hp, and on a big tank, and the big tank does not get any water in it.
The whole tank gets hot enough that all the water goes in the lines. There are 30+ water traps, one before each quick connect on the wall. They catch all the water.
The water trap should be as close to you and far from the compressor.

[raygreenwood]

[modok]

I haven't really thought about painting in a while, but if using a regulator there should be no water condensing out after the regulator. So.....tank, then long hose, then water trap, then regulator, then short hose to your gun, should work well.

[Air-Cooled Head]

First, I want to thank all who gave such good advice and ideas. That's what I love about the Samba.

I'm having the garage wired for 220 in a few weeks, then I'll be keeping an eye on Craig's list for a 2 stage compressor.

Meanwhile, I combined Buguy's advice, and eshan2's suggestions and got to a solution. Still have the BS compressor.

Now, I have about a foot of 1/4 inch steel pipe, that goes into 40 feet of 1/2 copper coil (about 35 feet is submerged in water in a 30 gal plastic garbage can), then another 15 feet of 1/2 inch steel pipe, into a water separator, then into the hose. A cheapie filter at the tool.
There's a drain on the tank, at the bottom of the copper coil, another after 10 feet of steel pipe.
I've been using my DA for 20+ minutes at a time w/o it spitting. It hasn't been 90+ degrees w/ 90% humidity like it was when I originally posted, but so far, so good.

Thanks guys for your help and advice.
_________________
Everything known to man has been written.
Readers are Leaders!