# Observations and Lessons learned installing compressed air system.



## Whiskers (Nov 6, 2012)

Anyone familiar with my postings knows I'm setting up shop, and one of the things I have been working on heavily the last couple days was a good compressed air setup. I did lots of research in various forums, many of them garage etc and the universal consensus was the best materials for this is metal pipe. If your into painting cars, galvanized pipe may be best, otherwise ordinary black cast iron pipe is fine. The reason for the difference is that the black pipe is more conducive to rust, and rust to a car painter is like silicon is to woodworkers.

My design started simple, I wanted air available everywhere while keeping my compressor conveniently stowed away. In one corner of my garage I'm building a equipment closet that stows my compressor, dust collection setup, water heater, and has storage for lots of other stuff or future equipment. My super fancy HF $110 compressor will sit on a shelf over my hot water heater. Air outlet consisted of a HF reel which hangs from the ceiling and has 50' of rubber hose. If you ever been in a professional garage you have probably seen similar things. All I needed to do was connect them. A light switch on the outside of the closet would turn on/off the power to a ordinary wall outlet to power the compressor on and off without having to run in and out of the closet. It got expanded a bit cause upstairs over the garage is my master bedroom, and I wanted a air outlet there near my desk cause I also like to make models, especially in winter when it cold, and do airbrush work. Since I don't want to run up and down the stairs when I am playing I am putting in a 2 way switch with one upstairs and one on the outside of the closet.

Rule 1 which is universally accepted among most anyone is avoid any and all plastic type materials. It will invariably fail over time. Some people use these fancy expensive plex and other weird plastics but they are expensive, will eventually degrade and fail, catastrophically sometimes, and are usually very small in diameter restricting airflow. I'm not sure how significant it is, but if you got runs of 1/2" metal pipe it going to act just like the tank on your compressor expanding the stored air. Maybe one of you know it all mathematicians will pipe in and tell me how many gallons of air my 30' or so of 1/2" diameter pipe has added to my total storage.

One problem with working with metal pipe of any kind is you have to pick one end and run to the other. If you ever have to break a piece apart you practically have to tear the entire line out. A thing called a union helps solve this problem as it can be tightened on both sides, but be prepared to work from end to end and get it right the first time as you go.

Rule two is be prepared to pressurize and test every couple pieces of pipe. Metal pipe is a pain in the ass to get a air tight seal. Now here is where some of my new found experience has come in. In the past I've always used teflon tape to seal air connections. It seemed to work better than pipe joint compounds and was much more convenient cause usually it seemed when I needed it the pipe joint compound would be dried up and useless. Well here the thing, for brass or chromed steel fittings the teflon tape is fantastic, the best material. It works, cleans out easily if you change fittings, and is always ready to go. But it sucks to seal pipe, it won't work. The threads are too big and sharp. I'm just telling you this up front so you won't waste your time with it. Small brass or chromed steel fitting, go with the tape, Pipe, you will have to use the pipe joint compound, and even than, test test test, cause metal pipe a pain.

Rule three, don't be a gorilla, you do have to tighten things up good, but it doesn't take a terrible amount of pressure. Besides, cast iron is a soft material, easily stripped.

Rule Four, when drilling holes thru wood for the pipe to run through, and you should, make pieces to support it etc, running thru floors especially this applies, go a little oversize. Don't drill a hole just the perfect size for the pipe to slip thru. It a pain in the ass when dealing with large holes to widen them later, and with pipe it needs a little wiggle room to get it in position properly. A half degree off you can't get the fittings and pipe to align. Go back later with some silicon caulk after the pipes are in to seal them into their holes to shut off bug or air traffic flows if that what your concerned about. If your working with 1/2 pipe it is 7/8" outer dimension. When Drilling thru a wall or floor, go a full inch when drilling the hole, you will be glad you did. For support pieces that you may make 15/16" is purrfect.

A few more notes, not rules. This stuff is nasty to work with, be prepared to become really dirty. Find some clothes you have written off and are ready to throw out and just wear them from start to finish on the job, and than toss them.

Black pipe can be painted, Surprise!  but prepare first before putting it up. Great way to deal with any pipe, black or galvanized, is get a gallon of WD40 from tractor supply or somewhere for about $20. Wet paper towels or a sponge heavily with it and clean the exterior of the pipe. Galvanized pipe has a oil coating on it to help release it from the mold, and that oil is kind of hard to clean, Black pipe has something even more terrible and insidious, and really a pain to clean but the WD40 does a great job of removing it. After that you than have clean the WD40 off, which is still a oil, but a much easier to clean oil. Simple Green works great for this. Let it cook in the sun a bit to dry and prime, paint, enjoy.

If there is any interest in this thread I'll come back later and post pictures to show methods of how to run the pipes them self, Especially for water drainage which is super important and how I did some of the supports etc. It late now though and I just got all that nasty black pipe gunk off me and not going back into the garage.

One more final piece of advice, when sourceing your materials, find a nice local ma and pa type hardware store for all the small stuff. Fittings, Nipples (short little pieces of pipe), etc. Buy extras and lots of them, you always seem to be off in measurements, have to make little jogs around unexpected obstacles, etc, and it better to have lots of stuff to work with when doing the project rather than waste time running back and forth to the store. With the small stores returns are easy. For the pipe itself, go with Lowe's of HD, they are as cheap as anyone and will cut and thread it for you. Also it cheapest to buy a 10' hunk and have it cut and threaded rather than buy the pieces they already cut for you. I don't know why that is, it just is. They may say they can't cut and thread less than 3', but that not true, they can go down to a foot. Just need to find a smart boy who knows the machine.


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## mojapitt (Dec 31, 2011)

Good you're making progress. I would suggest that you have a filter on the air intake of compressor if it is with the DC. Dust is a compressor killer.


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## Whiskers (Nov 6, 2012)

hmm, something I hadn't considered. I have never seen the DC spitting dust, guess when it all together I can observe it for a bit. The compressor has a little filter, but it is weak. I'll keep the concept in mind, but I've never seen dust coming out of the dust collector. LOl, easy detection, run dust collector, walk in closet, if i sneeze there might be a problem.


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## MalcolmLaurel (Dec 15, 2013)

Actually plastic piping is fine for compressed air, as long as you use suitable tubing that's rated for the pressure you're using. PVC water pipe is not suitable as it's brittle and can't take repeated pressure cycles. I used 1/2" polyethylene tubing ($0.32/ft from McMaster) which is rated 150 psi, with matching plastic compression fittings. Cheaper and a lot easier to work with than black pipe! I used galvanized pipe nipples at the quick disconnects, which I mounted to the ceiling at various points.


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## crank49 (Apr 7, 2010)

Copper pipe is a great airline material. It is used in many industries.
PVC will explode eventually.
PE if designed for air service is good and it's easy to install as Malcolm said.
I worry about plastics due to UV degradation, but some are specifically designed for the purpose and should be okay.
To the OP, I have used Teflon tape on black and galvanized pipe fittings for 40 years for air, gas, some hydraulic and all water piping and never had a problem as long as the fittings were well made. Today it's hard to find quality fittings as most of them are cheap ass imports from India or China, especially in the box stores. Maybe your fittings are the problem.


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## Finn (May 26, 2010)

I put my air compressor in a separate building and put my dust collector outside in a, built for it, enclosure. No dust in my compressor and I cannot even hear the compressor from inside my shop.


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## Grandpa (Jan 28, 2011)

Teflon tape lubricates threads so you can actually tighten the joint more. Since pipe threads are tapered this can be important. I use a pipe thread dope that has Teflon in it. I like it although it can be messy. I haven't experienced this problem with Teflon tape though. It is specifically designed for gasses such as air and not actually designed for water. One thing you need to remember is to not go over the end of the threads because you will get small pieces of the tape in your tools. I also believe the galvanized pipe will have small particles of galvanize come loose and get into your tools or finishes. Use black pipe with water drains and a good filter at the business end. water and oil can be separated from your air.


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## shawnmasterson (Jan 24, 2013)

I used pex with metal fittings (rated at 140 psi) in my shop 4 years ago, and have had no problems. It has been in my stepdads body shop for 15 years and never missed a beat. I feel you are being very judgemental and dismissive of pex. It is a thousand times easier to run. It pulls through walls just like wire. also it doesn't hold cold like steel pipe, so there will be less condensation and no rust ever.


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## Grandpa (Jan 28, 2011)

My friend owns a machine shop. He installed PEX for his compressed air. When he changed buildings 4 years later he took the PEX down and moved it with him. So far he has had no problems with bursting or shattering.


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## MalcolmLaurel (Dec 15, 2013)

Michael, yes, copper is also a good option… easier than iron but more expensive these days. Where I work, all the air lines are copper, up to 3" (it's a good sized plant).


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## Whiskers (Nov 6, 2012)

Thought I would get back to all the posts you guys made and make some replies and ask some questions.

For those talking about Pex, I've heard about it, and many people use it happily, but the Pex I've seen is very small in diameter and expensive. In retrospect, I would have done my little run to the upstairs in Pex if I had thought about it, cause air brushes don't eat the air that tools do. It sure would have been easier. I even have a 2nd air regulator that will be mounted to the wall that cuts the pressure down to 20-40 lbs for the air brush. I should mention that I have some automotive air tools that eat more air than woodworkers typically need.

Crank, can you buy anything that not made in China? Yeah China was printed on all the fittings I have seen, from anywhere.

Jim, my little closet is expensive enough, can't afford to build a outside enclosure and run power to it.

Grandpa, I'm not sure the machine at Lowe's tapers the threads.

Copper, yes it is great material, but super expensive. Most of the posts I seen from folks who used that specifically were into auto painting, and didn't want any rust, or managed to scarf it up from some salvage operations they pulled off. Also, doesn't copper have to be Braised with a torch? There is no way I could have safely attempted to learn braising with a torch in the spaces I ran my pipe, My house would now be a pile of ash. I can't see how learning to braise and maneuvering a propane torch in confined spaces is easier than operating a pipe wrench.


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## hydro (Aug 9, 2013)

Iron pipe of any kind, black or galvanized is the worst possible option for a properly designed compressed air system. I exclude PVC here because it is just dangerous, foolish, and effectively illegal per OSHA regulation. The problem with Iron is that the water and acidic oil residue from the compressor corrodes it from day one and galvanized is particularly insidious because the zinc will come off in flakes as the inside of the pipe corrodes. Also, the threading process is difficult to do in the first place, is prone to leakage, and very difficult to change. Copper is just too expensive to consider commercially these days.

The industrial standard (Where keeping pipe fitters busy threading pipe is not a priority) has shifted to thin wall aluminum pipe systems. Corrosion is not a factor, few tools are required to assemble airtight joints, it is easy to change, and the cost is only slightly higher than iron pipe once you consider the time spent assembling the system. Do some research and see what the advantages are.


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## Whiskers (Nov 6, 2012)

LOL, thanks for the amusing post hydro, it almost reads as a PR piece, but the concept is ludicrous. Industry standard my ass. How can a product that don't exist be a standard. I have never ever seen a piece of aluminum pipe in any store. I have also never heard of anyone using aluminum in a compressed air system in any forum. Aluminum is also very expensive, maybe even more so than copper. It also soft and not as tough as other metals. Since aluminum pipe does not exist in a commercially viable form, it not relevant to speak of.


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## DIYaholic (Jan 28, 2011)

Aluminum compressed air tubing….
http://www.rapidairproducts.com/fastpipe.asp


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## Whiskers (Nov 6, 2012)

LOL, mail order 10' pipe? are you kidding?


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## DIYaholic (Jan 28, 2011)

FREE delivery available to store….
http://www.northerntool.com/shop/tools/product_200582745_200582745


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## Whiskers (Nov 6, 2012)

Who is that? Great free delivery to a store I don't have.


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## fge (Sep 8, 2008)

I just ran compressed air throughout our 40 by 80 shop. In our last shop we just used 3/8" thick wall rubber hose. It worked perfect. So I did the same thing in our new shop. The hose is very affordable and very heavy duty. The hose is constructed as compressed air hose so strength is not an issue. There is no drop in pressure that affects our machines. We run about 130 psi at the compressor, located just outside the building. We have 75' runs and a few "T" splices. Connections are made with simple brass plumbing fittings found at any hardware store. Extemely easy to run and get air tight connections. I have no leaks using the teflon tape method.

I doubt the hose will ever fail. Even if the hose did fail, it would happen when we were present because of our process of shutting compressor down nightly. And in the even of a failed hose, the repair is easy, and worst case new hose is very affordable. Unlike a plastic material, if rubber did fail, no chance of getting sprayed with shrapnel. We drain off our tank every night after shutting the shop down. Lines are only pressurized during the daytime. Doing this also helps maintain the inside of the tank and helps drain condensation from the tank. We kill the breaker to the compressor every night and go to bed…

Wherever we need to regulate pressure (Blum minipress, spray gun, etc…) we just install a regulator.

Been running on rubber hoses since 2010 and no issues ever.

Easy goes it.

Edit:
Did not want to seem intrusive since this thread is about running steel pipe. Just wanted to offer another effective and very affordable method. The black pipe method certainly has several advantages in that it would be the most durable method and certainly using 3/4" ID would allow practically 0 drop in air pressure while holding full pressure at every stub out. Just in our case, and with most every other woodworking application, air pressure above 100 psi is overkill so using rubber hose would be more than adequate.

Thanks for the lesson on steel pipe though, you have several great rules to follow should we ever upgrade in the future.


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## CudaDude (Jan 30, 2012)

Thanks for the write up Whiskers. Something I plan on doing in my garage someday. Interesting what you said about having more air storage with the piping. My FIL's garage is piped with air, and always wondered why his compressor (which is smaller than mine) cycles a lot less than my does. Makes sense that he has more air storage. I might have missed it in your write up, but did you purchase a pipe threader. If so, what did you buy?


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## hydro (Aug 9, 2013)

Whiskers, wake up and smell the coffee. It is apparent that you don't out get far past the box stores. Iron pipe for compressed air is going away and I see it every day out in the field, calling on industrial and commercial shops. Get ready for that wet rust flowing from your system.

Do some homework and search these systems:

Rapidair
Airnet
Champion
Prevost
Infinity
Aircom
Transair


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## Grandpa (Jan 28, 2011)

Whiskers, pipe threads are tapered. I believe they are 3-1/2 degrees. If they are straight they are conduit threads. Those will only go about 1 or 2 turns into a pipe coupling. You are correct when you say there are limits on the size of PEX pipe. It only comes in 3/4 inch max diameter as far as I know. I have not seen it for sale in anything larger. It is produced primarily for water supply systems in homes. It was first designed for heating loops in concrete floors. It does not burst when frozen. I personally have not used it for compressed air but I might. I have used wire re-enforced rubber hydraulic hose. This has a burst rating of 3000 PSI ( the specific hose I used). We could buy it at my workplace cheap (used). They took it off old equipment. I would buy 50 ft lengths. That works very well Jerry. I think depending on the iron pipe for more capacity would make no difference unless the pipe was 4 inch diameter and 30 ft long.

My son was instrumental in completing the building his work place was moving into. Our city charges us a tax. This tax is used to promote new industry. The development people will build a shell with no floor just a wall and ceiling. IF your company wants to move into it they can set up their business and own the building in 10 years. The agreement is they development people will have the floor poured depending on the machinery you will use and its weight. They have it wired and heat and A/C installed. Everything needed is installed then you move in. My son looked around and said I don't see the air piping. We specified a 4 inch welded steel pipe. The man there said we install 4 inch PVC in all our jobs. My son said not here you don't. The man said yes we do. My son said get your boss over here now. I will be back when I get the papers I have. He had researched the use of PVC and air. The lubricant used in compressors makes the PVC brittle and it shatters. The boss man came out. My son handed him the papers and said read this. The man read through the paper. My son said if you want to be liable for any accidents from using PVC improperly then I want you to sign this paper taking that responsibility. The boss man told his people to take out the PVC and install welded steel as specified. They wanted to bully someone into using the wrong material but they tried it on the wrong people. I wouldn't use PVC however I have a friend with a small machine shop that has used the same PVC everyday for the past 35 years. No breaks. Could be a time bomb.


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## fge (Sep 8, 2008)

Condensation in the steel pipe lines could be an issue down the road. Clean water already causes us issues when spraying and our DA sanders do not like the taste of water either. I would imagine rusty water might be less attractive to our tools. I would suppose that is an issue everyone should consider. They do make in line water filters which helps.


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## shawnmasterson (Jan 24, 2013)

I just want to put it out there that pex comes clear up to 1 1/2" diameter.


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## Grandpa (Jan 28, 2011)

Thanks for the info Shawn Masterson. I don't have a local supplier that stocks that size but it is good to know it is available somewhere.


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## shawnmasterson (Jan 24, 2013)

I could probably get it from a supply house. I really see no need. I have a 30' run of 3/4" pex from the compressor to the front of the shop. there is 1 T in the middle that goes to my ceiling mounted hose reel. I run everything on this, and by everything I mean from a DA to my 3/4 IR impact with no problems. I used to use a 1" impact that was an air hog. I had a surge tank set up. By a surge tank I had a 30 gallon tank mounted on the front wall with a 3/4" pex supply. From there I had a 1/2 goodyear hose to run my 1" impact. I just want to put it out there to those who are concerned about the size of the lines, I just want you to look at your fittings and the size of you air hose. 90% of them have a 1/4"-3/8" hole. I understand that getting the volume of air you need is half the battle, but really how big of an airline do you need? Also if you read the original post, I guessing he is using a HF pancake making around 5 cfm that would run everything it is capable of running on a 3/8" hose at 90 PSI, so why not use something as simple as pex. The cost is nothing compared to steel or copper even with the cost of a crimper.

My final thought on this is overkill is not always better. 
Be sensible where you spend you budget and it will go a lot farther.


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## Whiskers (Nov 6, 2012)

Mine is a real full sized compressor, not one of those pos oilless pancake compressors. It is a HF unit though, highly rated though relatively speaking. Not sure what it's limit is, but it much higher than 5cfm.


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## shawnmasterson (Jan 24, 2013)

I'm sorry for the assumption on my part. I read "My super fancy HF $110 compressor will sit on a shelf over my hot water heater." in the original post and figured it couldn't be a very large unit. I know I can't pick mine up to put it on anything due to the weight and height. It stands 6' tall.

no hard feelings


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## Whiskers (Nov 6, 2012)

no hard feelings. I wanted one of the tall vertical units, but couldn't justify spending that kind of money, so when the HF unit came along I grabbed it. Mine is one of the normal sized horizontal types with 2 wheels on one end and the metal handle for pulling around the shop. About 3' long total and probably about 2-2.5 foot tall. It would be a strain for me to sit up on the shelf it will go to by myself, but I probably could do it. I'll probably just wait til Gigantor the UPS man makes another delivery and set some cookies or cake out for him. Much easier way to get large things lifted. Would be really easy for 2 people to lift mine, even easier for 3.5 like Gigantor.


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## Grandpa (Jan 28, 2011)

There is a need to use larger hose or pipe when making long runs. Just like a long run with an extension cord. Friction will give you an air loss after the first blast. Keep that surge tank at the other end of the line.


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## shawnmasterson (Jan 24, 2013)

You know I thought that same thing about the tank. I took it out since I don't have the 1" impact any more. So I went from 90 gallons back down to 60. The tank was in the way when I put in my phase converter. I still have no problems, but when I am sanding I notice the drop off as the tank drains. As soon as I find a new space out of the way I think I will put it back in just for the extra storage. I just wanted to note in my stepdads body shop it has 4 lines that are 3/4" pex from the compressor (massive IR 10hp 120 gallon) to random points of use with no surge tank. Each run is an average length of 60'. There is a small manifold so the 4 lines can be turned off independently. His system performs flawlessly. I think the massive line systems are intended more for 10,000 SQF factories.


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## ClintSearl (Dec 8, 2011)

There's a lot of misinformation in this thread.


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## shawnmasterson (Jan 24, 2013)

if you feel you have better information please feel free to note any corrections. the more info we have the safer we can be


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## Grandpa (Jan 28, 2011)

I have a friend that lived in the country so there was no TV cable. He got what we call a "break over pole". It has a stiff arm that is about 15 to 20 ft tall. It has a saddle in the top and a 60 ft pole that hinges in the saddle so you can break it over and put on your antenna. He got everything ready and wanted to paint it before he set everything up. He just left his compressor in the shop with the electricity and ran a hose out to the work area for his paint gun. When he regulated the air at the compressor he didn't have enough air to support the gun. He finally ran some 1/2 inch hoses as far as they would go and used unregulated air until he got to his pole. He got a small regulator that clipped to his belt and regulated the air down for a small whip and the paint gun. It worked fine but he couldn't maintain the air and know what pressure he had at the end. There is friction in a hose. same with hydraulics.


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## Whiskers (Nov 6, 2012)

If I ever have to do something like this again, I will definitely look closer at Pex, but I honestly thought it was only available in very small lines. Most of what I have read about pex was running low pressure lines of fluids thru concrete floors. Sometimes water, Sometimes something else, depending on where you live. I honestly am not familiar with the material so went with what I knew. The only supplier of pex I have seen for air purposes sells this little kit, that is super expensive. A lot of people like that kit, but it would have quadrupled the cost to me and I would have ended up with tiny little air lines. Considering how short my pipes are now, the only change I might of made is use galvanized rather than iron pipe in case I ever did want to get into painting down the road. Since my shop is not that large, and my lines not that long, the cost difference would not have been that substantial. I do have purge valves strategically placed to blast water out of my lines so I am not expecting condensation and rust to be a major issue. I would like to get some kind of filter to put at the juncture to my hose reel. Will have to check out what the local HF sells for that.


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## Grandpa (Jan 28, 2011)

Try using a drip leg at each of the quick disconnects on the wall. This will help you with purging moisture. I think you have done the best thing with the black over the galvanized pipe. I believe you will have too many problems with the galvanize coming loose inside the pipe.


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## Whiskers (Nov 6, 2012)

Grandpa, I think I did just what your saying, at each end where the intake and the reel are I joined the pipe to a T-piece, and have a 6" nipple pointing straight down. At the end of the nipple is a valve which can be opened to purge any water that has collected. Upstairs I didn't do this cause the pipe runs straight up and water can not collect there, but I do have this little filter thing that has a water trap built into it that is attached to the valve. Part of the air brush setup.


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## Sunstealer73 (Sep 2, 2012)

I used the Rapidair setup when I built my shop. It all went inside the walls at the same time as the electrical. Working great for almost three years now and everything is nice and neat.


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