Gunsmithing Compressed Air Setup help

[jonaddis84]

So Ive run into some issues with my air setup all the sudden, want to get some opinions. Ive been running this setup for about a year now and havent noticed any issues, until now.

My shop building is divided into 3 bays in a 30x60 pole building. Shop is in the middle 20' bay and insulated/heated. End bays are not heated. I put my compressor in one of the end bays so that I wouldnt have to listen to the thing all the time, and to save space in the shop. Compressor is an IR single stage. I just have a water separator right off the tank, flexible line from the separator, then it goes into 3/4" Sch80 PVC for the manifold running into the shop. There is probably 30' of pipe before it gets into the shop.

Well the other day I was sandblasting and all the sudden the air quit, thought maybe I forgot to turn the ball valve on the tank on, but that wasnt the case. The flexible line between tank and PVC was frozen. Thawed it out over night, was working fine, sandblasting again and it happened again.

So, my question is what would you recommend to get the water out of the air?

I think I will build a small room around the compressor, insulate it, and keep it 50* or so during the winter, and have vents I can open up in the summer to let hot air out. But this doesnt solve my root problem of having excessive amounts of water in the air.

I guess I cant figure out why its gotten so bad now, and Ive never noticed water in the air before? Wouldnt it be less noticeable in winter when the humidity is low? Also the air should not be getting heated up quite as much.

So Ive done some research and have a few options Im thinking of...

1. Install a homemade aftercooler between the compressor and the tank, with a water separator after the cooler. This solution is time consuming and relatively expensive. I like the idea of getting rid of the bulk of the water before it even goes into the tank. Heres an example... My IR SS5 air compressor - The Garage Journal Board

2. Run 100' or so of black pipe around the garage bay the compressor is in to cool the air off, then have a separator at the end of that run before it goes into the shop. This is also expensive and time consuming, and unsightly.

3. Buy a couple water separators and install them directly before each outlet of the air manifold (before sandblaster, air line at lathe, hose reel I spray cerakote with). Also install a drop pipe with ball valve at the junction where the flex line from the tank connects to the PVC manifold to catch some heavy water there.

I like option 3 for now since I dont want to spend a whole day freezing my ass off building the aftercooler or whatever. But do you think this will at least alleviate my problem for now until I can dig deeper into solving the water issue closer to the compressor?

Thanks for the help!

Jon

 

[Jumper]

Insulate the flexible line between the tank and PVC manifold. Now that it's winter, your compressor is intaking colder air, and sandblasting is using a lot of air causing a pressure drop in your line as it exits the tank. When air pressure drops, water will begin to condense. This is supposed to happen in your water separator but it looks like the conditions are right that it's happening before it. If you insulate the line, it will retain more heat from compression and make it to your separator before it condenses. You would probably solve any future problems if you moved your separator to the heated partition of your shop.

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[Hogshooter]

What Jumper said or wrap the flexible air line with some heat tape for the winter.

 

[Redcreek1]

I would never even consider doing media blasting on guns for Cerakote and then coating without a refrigerated air dryer w/ coalessing filter. You are contaminating your balst media with both oil and water and spraying with contaminated air. My air goes through a 100cfm coalessing filter then through a 115cfm refrigerated air dryer, which feeds the whole shop. I then run another 3-stage desicant filter/dryer before the spray booth, just to be safe.

The other day my new shop help forgot to turn on the dryer and it wasnt long before the media in the blast cabinet was damp and clumping up and the filter ($150 to replace) was clogged. We had to replace both filter and media.

 

[Pinecone]

How often do you drain the water out of the tank?

If you are not doing that on a regular basis, you can build up water to the point is causing additional issues. They do make automatic drains that drain when the water level gets up.

I agree, with any operation with painting, you need CLEAN air. You need an oil separator and then some drying system. Refrigerated is best. But there are other options.

OH, and BTW, using PVC to run compressed air it NOT recommended. It can shatter and become shrapnel.

These people have some very good solutions that are easily installed by yourself:

Compressed Air Piping | Compressed Air Systems | Do It Yourself Compressed Air Systems

 

[jdonovan]

So, my question is what would you recommend to get the water out of the air?

I think I will build a small room around the compressor, insulate it, and keep it 50* or so during the winter, and have vents I can open up in the summer to let hot air out. But this doesnt solve my root problem of having excessive amounts of water in the air.

The other suggestions about insulating the lines is just not going to help as the line is AFTER your water removal filter. Insulating that is just going to move the water problem down the line.

A 'cheap' aftercooler that many compressor makers recommend - Run about 10' of pipe up at an angle from the compressor outlet. This will allow you to cool the air, and get the water to drain back to the tank where you can remove it. If you can't get the pipe setup to drain the water into the tank you'll need to put a "T" with a short length of pipe and a ball valve to use as a drain port.

If you have the bay height to do it... 2 10' pipes to the ceiling, with 2 90's and a 4-6 piece between them. Put T traps and drains at then bottom of both legs.

A refrigerated dryer is super nice... the good industrial ones are very pricey. HF will sell you one for $400

As redcreek said, if you are going to use shop air for paint, then you REALLY REALLY REALLY need to get serious about clean air, and get into a 3-stage filer system with desiccants. Things you can get away with in 'auto shop' air, will kill your results if you try and paint with that kind of air.

Also install a drop pipe with ball valve at the junction where the flex line from the tank connects to the PVC manifold to catch some heavy water there.

Anywhere in an air system where you have a 'low spot' should have a place to catch and drain water.

Pipe runs should slope to a place to catch and drain water.

Adding an additional filter at point of use is a good idea, and is the norm in most industrial systems. My air system runs all the plumbing at tank pressure. It gets filtered , and reduced to needed pressure at point of use.

When I setup my shop air system I found a very nice tech-pub from IR about how to design an air system, where to put in traps etc.. lots of good ideas in it.

 

[jonaddis84]

I do drain the tank regularly, this compressor does not get used every single day as I do not do this full time, so I dont believe that to be the problem.

Since refrigeration is out of my price range, I ordered up parts to build that aftercooler setup I linked to above. I also ordered a coalescing filter to put after the tank, and Ill move the cheaper coalescing filter thats already in place to before the air line I run cerakote gun off of.

I think Ill also put a good size drop leg out of galvanized pipe in there as I never did anything like that when I put this together.

If Im still finding water vapor in spray line Ill build or buy a desiccant dryer to stick on there.

Thanks for the help thus far, I probably should have put more time and effort into my air setup when I started, but everything was happening at once moving in and still working full time.

Would you recommend I still build a temperature controlled room around the compressor for wintertime use? I guess if nothing else it will insulate even more of the noise of the compressor running, as long as I can keep the room cool enough during the summer. Hell, if I can stick the aftercooler outside that room it really shouldnt get that hot in there as that is taking off the majority of the heat other than the actual pump head (which is a lot less surface area than a 60gal tank thats 125 degrees).

 

[Edds]

The water is condensing in that pipe because the temp of the pipe is cooler than the temp of the air. Is that flexible line one of those curly lines?

 

[BPaulk]

You can go to Harbor Freight and get a refrigerated dryer for around 400.00 dollars. I have one at my Cleaners.

 

[jonaddis84]

Wish I would have seen that HF dryer before I ordered all this crap, especially since it seems to have very good reviews, normally I would never think of buying a piece of equipment like that from HF though.

Im hoping to solve several underlying issues I have with my system in this little upgrade, I will post results once I get it all put together. One issue being that flexible line I was speaking of is just a ~20' piece of regular old air line that was laying around and I used it as the flex coupler between tank and rigid manifold line. Plus that has a 1/4" quick connect in it which is a restriction, and not to mention a very small point where water can easily freeze to clog the line. I have ordered several shorter 1/2 hydraulic lines to make all my flexible connections.

On that note, if anyone needs hydraulic lines for a good price check out surpluscenter.com I thought they were very good prices compared to even ebay. Not sure I would use them if you actually need 3000psi rating, but for 140 I think they will work.

The flex line I ordered to run from pump to aftercooler is a corrugated stainless flexible metal hose I got from here, Flexible Metal Hose , another item I thought was a good value compared to other hoses I saw online. I just got it with standard hex NPT ends and got some NPT swivels from surplus center to make the connections easier.

 

[Pinecone]

Realize, that whatever you do without refrigeration or dessicants the air ends up being 100% RH. Refrigeration works by cooling the air down to below ambient temp, then when it warms back up, the RH drops. Desiccants just flat remove moisture.

What is likely happening (now that I have had time to think) is that the air in your tank when running a high volume, like sandblasting, is warmer than the outside air (warm to hot compressed air coming in keeps the tank air warm). As it goes though the flex, the outside air temp drops the air in the lex down, condensing out water, which freezes. Insulating the flex, as mentioned would prevent the condensation and freezing, as the air would stay warm until it entered your shop.

The after cooler, especially in winter, will remove a LOT of moisture, as you can cool the air to below freezing. However, cooling the air to below freezing in the aftercooler can lead to the after cooler freezing up. Same with refridgerated dryer. They can only get the dew point down to about 35F. Below that, they freeze up. So be careful with how wild you do on the after cooler if the temp in the area is below freezing. And make sure you have enough sump to hold the amount of water you will collect (a LOT).

You do not need to be sprying out a water mist from your air hose to cause issues. You can actually have water condense on a surface, or with blasting, have the media absorb water from the compressed air.

There are desiccant snakes you can buy (4 - 6 feet of 1.5" - 2" OD hose, packed with desiccant). I use them for spray painting things. Not cost effective for a lot of work, but for occasional use, they work well.

 

[jonaddis84]

Hopefully I have the problem solved now. After cooler between pump and tank. Tp tools separator after tank. Big galvanized drop leg after that. Coalescing filters at each station. Insulated and temperature controlled room around the compressor.

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[BPaulk]

Jonaddis84, your Air compressor needs fresh air. You see the big pulley that the belt ride on that drive the pump. That not only drives the pump but it is the fan to cool the air compressor head. There should be a arrow on it showing the direction it needs to turn. I sell air compressor's and commercial Laundry equipment and own a dry cleaners. You are welcome to call me if you need too. 501-276-7811 cell #

 

[jonaddis84]

There is a good 8-10" behind the flywheel, and there are two 12" square vents in the side of the closet. In summer I will probably add an electric fan directed at the pump head also.

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[BPaulk]

I could not see them from the pictures. Good luck with your install.