Copper or Plastic for air system piping?

[Aviatordave]

Hello! So I’ve got a new compressor ordered. (DeWalt 80gal, 5hp, 2stg, 175psi, 17cfm) This is a long awaited purchase as my only compressors before this have been 6 gallon pancakes for nailguns and inflating the occasional kids toy. I’m researching the heck out of piping systems and learning all about the benefits of avoiding 90 deg turns and looping the end of the airline back to the source to avoid pressure drop over distance, etc. I’m fairly certain . . . or at least I was, about going with copper. (Not overly worried about the cost.) Now after reading about some of the plastics that can be used I thought I’d poll you folks to see what your experiences have been. I know you can’t use PVC, CPVC or any other non high pressure pipe but ABS, HDPE and a few others are evidently options. Anybody use plastic of any kind in their system? Like it? Wish you would have used something else? I’m basically still leaning towards copper but want to do my due diligence for research.

Also, has anybody used a rubber hose between the compressor and the rest of the system to isolate vibration? If so, what kind of rubber hose did you use?

Thanks in advance,
-Dave

P.S. I’m pretty well up to snuff on the needs of dry air, filters, drains, etc needed for an air system. I just want to talk about the piping.



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[ForceFed70]

I used the RapidAir system - It's basically just PEX. Works great.

Copper is ideal but $$$. Black steel is another cheaper option that also works great - just harder to work with/install.

 

[Muckin_Slusher]

My opinion is that I wouldn't have a problem using pex if I could run the pex inside the wall cavity, and then stub out with copper or black iron. This would be to protect the pex from light which degrades it over time, as well as physical protection, but mostly because it looks terrible and is nearly imposible to run straight and nice and neat.

 

[EOC_Jason]

The RapidAir systems would be the way to go if you want plastic, but otherwise copper is an excellent choice as it will continue to cool the air down as it flows through the line.

Black pipe is another choice if you want to save a little money, however depending on how man bends and drops and such threading all those ends can be quite tedious.

People have used hydraulic hoses, steel braided hoses, short rubber hoses (you can usually find them with the regular 50' sets at the stores)... You can run copper from your compressor to the wall, just be sure to add at least one loop for the vibration, if you have room leave a few coils as that will add length and give additional time for the air to cool some.

 

[sberry]

How big is the place? You likely don't need loops or large oh es, there is a lot of concern over "pressure drop" here that doesn't mean squat. 97 percent of loss in these systems is in the secondary.

 

[Aviatordave]

I just stumbled onto the Rapid Air system after I made the OP. Looks very interesting. I like that it’s aluminum and easy to bend. I watched a guy on YouTube who made a straightening jig for his long runs and it turned out looking pretty nice. I’m looking more closely at this system now. Glad to hear some of you have it and like it. I’ve noticed that the kits themselves aren’t too pricey but if you have to buy extra fittings that seems to be where they put it to you.
With copper I was going to go to a plumbing supply and get some 3/4” grade L in 20’ sticks and sweat it all myself. My shop is 40’x40’ but there’s another 40’x40’ garage next to it. (A 40’x80’ pole barn with an internal wall dividing it in half)
The air will mostly feed the shop side but there will be a few runs to the garage side. (Paint booth will be over there, I want a general “air up the tires” hose next to the overhead door and also a line next to the 220v outlet for the welder in case I need to drag the plasma cutter over to the garage.)

I like the idea of a coil of copper between the compressor and the wall for the cooling effect. Thanks for that tip! I also hadn’t thought about how well copper radiates heat and would keep the air cool. I’m sure aluminum would do well at this also but coated with vinyl . . . Hard to say. That wouldn’t be a deterrent for me for the Rapid Air system though. The biggest advantage I see to the Rapid Air system is ease of running and assembly. Copper, otoh, is easy to sweat and very easy to add onto later when you get a new tool and need another drop.

Decisions, decisions, decisions.
Keep that experience coming! I sure appreciate all of it!

-Dave


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[EOC_Jason]

If you have a Tractor Supply near you people have posted them on clearance... You might get lucky...

 

[matt_i]

Hydraulic or high-end air hose for the snubber between tank and hard lines.

Imo copper is best, although its also the most expensive. If you go that route, look at Stay Brite #8 solder and Sta-Clean flux. Its stronger than "big box lead free", won't creep, and is also safe for potable water systems. Again, more expensive, but imo much easier to work with.

 

[Streetbu]

Copper first, then ABS plastic, black iron, specialty PEX meant for air systems, then galvanized. In that order, those are your best choices. Lots of factors determine which is truly the best for you including budget, and whose doing the work/how capable you are.

Edit: ABS plastic is a special order if it is even available to you locally, otherwise it will have to bought online. It is NOT ABS and not available at Lowe's or Home Depot. It also requires special glue and primer.

 

[oilslick]

L copper is easiest and almost same price black pipe in my experience. I used a semi truck air brake hose whip from napa to connect compressor ,cheep, cheep!

 

[Rc_Guy]

I used the RapidAir system - It's basically just PEX. Works great.

Copper is ideal but $$$. Black steel is another cheaper option that also works great - just harder to work with/install.

I think black steel is easier to work with and install, although I do it everyday as a sprinkler fitter.

 

[Lelandwelds]

How big is the place? You likely don't need loops or large oh es, there is a lot of concern over "pressure drop" here that doesn't mean squat. 97 percent of loss in these systems is in the secondary.

Hard to argue with truth like this but . . .

I do like a bit of overkill and believe "too much is just right". I like Lista or Lyons (especially if found for pennies on the dollar). I like Ferrari collections with car elevators. I wish I owned a full CNC shop with sheetmetal tools squeezed in too. I get distracted by shiny things.

I like PEX or AL-PEX with rigid pipe drops. I like hydraulic hose or stainless flex from the compressor. Some imported stainless pipe fittings are surprisingly affordable. The best choice is the one you are most familiar with.

You will not work your compressor hard enough for heat to kill anything. Pressure drop is moot. Rusting is a non issue if you remove the water. Even if you paint, most oil aerosols are stopped by even the cheap filters. Unless you have a bunch of friends using air at the same instant, loops are unnecessary. Three drops in the right place can service a 1500 sq ft garage pretty well. Even if you do everything "wrong" , including failing to drain your tank, you will probably get 5 to 20 years of service. If your compressor can't keep up, open another beer.

Aluminum pipe needs expensive fittings. Cutting and threading iron "just right" is a PITA even with a pipe threader. Copper installs can torch your building and draw meth head copper thieves. Plastics may not be UV or oil stable.

They all work. Pick the one you like. Install something.

 

[850xpeps]

I just did our 50x60 shop with 3/4” copper. It replaced the 3/4” copper line that’s been laying on the floor being abused for the last 30 years so my vote is copper. I had a hydraulic hose made to thread into the 1” bung on compressor and match the 3/4” copper npt end with a swivel so I can tighten. Was $40 for the hose. We run our 3/4” gun and sometimes 1” gun at the end of our run, probably about 96’ plus the 50’ of hose with no issue. I’ve read the rapid air systems leak. Sweating the copper together and doing the whole system took my no time at all by myself. I made the little manifolds and then just soldered them in at the wall. If you don’t get something straight moisture can build in the dips.

 

[The Cobbler]

in the grand scheme, copper aint a bad price for the average guy that knows how to solder and doesn't own cutters & dies for black pipe, in my opinion. it's easy to fix a leak ,add or tie in after the fact, etc

 

[midwestcj]

I’ve got trans air in my garage. Nice and clean. Easy to build the system and can alter it easily as well. It isn’t al that cheap though.


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[klassenl]

I ran 1/2 pex under the floor into the walls of my garage and them came out with some black iron fittings. Many may poo-poo on this for various reasons but it has worked well for the last year and a half. I don't do anything that has a high demand for air.

Next time (Lord willing there won't be a next time) I would go with 3/4 instead if 1/2 and I would run air under the floor to my benches that are in the middle of the floor.

 

[kbs2244]

What I like about copper or black pipe is that it is "open source."
You can get it anywhere.
You are not tied to one company for additions and repairs.

 

[rooster-tail]

I installed 3/4 black iron with 6-3/8 inch bibs in my garage 30 years ago. The only trouble I have had is NOTHING. I run 175 lb. of air and use the hell out of it building trailers, offroad cars, chopping roofs on cars, small sandblasting, body work and painting. I have a 1/4 inch ball valve on a drop at the lowest point to drain any water that collects in the lines after running hard. My son just finished his shop the same way. He said Homo Depot will cut and thread the ends free if you know what lengths you need. His is a little nicer than mine with ceiling mounted hose reals. Good luck with what ever you choose. I hope you get many years of use out of it.

 

[850xpeps]

Here’s my coupling setup

 

[HoosierBuddy]

I went with black iron for mine. I agree with the poster above who pointed out that it's "open source". When I've wanted to expand my system, I can just go to the hardware store and get what I need.

For small systems, places like your local hardware or lowes will cut and thread pipe sections if you know exactly what you need...but if you have access to pipe threaders (i.e. can borrow one) that would be the way to go. Not a lot too it as long as the dies are nice and sharp and you have good cutting oil.

Phil

 

[NUTTSGT]

My system is black pipe currently but at one time I did have PVC. I bought a cheap threader at HF with a 20% off and it paid for itself in that one job.

I bought a section of hydraulic hose with a swivel at TSC for the connection between the compressor and system.

 

[77Birdman]

I used copper in my woodworking shop a few years ago. Its fine, but like ya'll know, not the cheapest way. I used black iron in my garage which works fine, but I also have a threader (manual) and pipe stand. I thought that would be the cheapest way, but when all was said and done I could've bought a pre-made system out of pex. It def. would have been easier to install but I like the look of the hard pipes straight and painted in my garage. I cut a piece of standard rubber air hose a couple of feet long and that hooks from my compressor to the hard pipe on the wall. I use it all of the time with tools so I figured it would work for their as well. Have had no problems.

 

[Rodgers]

I think Cobbler said it best. I put in a 60ft 3/4 loop in the rafters with (3) 1/2 drops and hose reel in the ceiling. All copper. I put a ball valve for each drop. 30x36 shop, I have about $300 in material.

I was just trying to get something in now to use, I can easily add to it in the future.

 

[Smoker]

I just did this exact thing last weekend.

I went 3/4" black iron riser/header down the middle of the ceiling and 1/2" copper drops to each wall. Worked great, pressure tested with no issues.
I had a 3/4" SS flex hose custom made at the local hose supply place to connect to compressor to the riser. There's a fair amount of vibes when the machine is running so you don't want it hard piped.

Don't forget the drain legs at every drop.

 

[doubleot]

I just extended my air to the full length of the garage on the left wall. I used copper and don't regret it at all. Works great no leaks and I have 2 reels one at the front and one by the garage door so I have air access all through the garage and outside.

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[finn]

I have black iron, but when I extend the system to the back room, I'll use the RapidAir system.

Black pipe is too much hassle.

 

[Motorman55]

Take it from an expert....

 

[1966chevelle]

I just bought the a rapid air kit from TP tools. They were having a sale for 25%off plus free shipping. I got everything I needed for my 40x40 shop with 4 drops for $75 more then northern tool wanted for the kit. My buddy told me that rural king has the kits and fittings for cheaper then amazon.

 

[srr]

Copper is best in my opinion for all the reasons already stated. Your only doing it once, it's faster, gets rid of heat, looks good and easy to modify. I have a 1" 30' line running between the front and back door with a 50' hose reel on each end. Never any problems.

 

[clubairth]

Like you I studied a lot and there really is a wide array of good stuff out there.

I went with 3/4" Rapid Air for several reasons. I have a 30' X 40' shop and made a 360 degree air loop. Also built the straightener you found online and when done sold it to another guy here on GJ. Really liked the looks and how it forms. The blue stands out in the shop too. Supper clean plus every air drop has a water release which is a great idea.

Another good thing is Northern Tools sells it so you can get any bits and pieces you need locally, as I found the kits better priced on line. With the size of my shop I used a 300' kit and another 100' roll of pipe plus fittings and drops. My only real complaint is the air drops cost. But everything is chrome plated brass and of very good quality. I followed the directions and had zero leaks after the install or since (Almost 3 years)

Here is how I installed it;

Here is the handy dandy pipe straightener.

Post pictures of what you install to.
.
.
.

 

[lis2323]

Like you I studied a lot and there really is a wide array of good stuff out there.

I went with 3/4" Rapid Air for several reasons. I have a 30' X 40' shop and made a 360 degree air loop. Also built the straightener you found online and when done sold it to another guy here on GJ. Really liked the looks and how it forms. The blue stands out in the shop too. Supper clean plus every air drop has a water release which is a great idea.

Another good thing is Northern Tools sells it so you can get any bits and pieces you need locally, as I found the kits better priced on line. With the size of my shop I used a 300' kit and another 100' roll of pipe plus fittings and drops. My only real complaint is the air drops cost. But everything is chrome plated brass and of very good quality. I followed the directions and had zero leaks after the install or since (Almost 3 years)

Here is how I installed it;

Here is the handy dandy pipe straightener.

Post pictures of what you install to.
.
.
.

I do all mine in copper, but NICE JOB on the straightener![emoji106][emoji106]

 

[rburke65]

Yes...real nice job on the straightener and I like your "uncoiled" as well. How many bucks do you think you hav in the straightener?

 

[Farmallgray]

Where did the rollers for the straightener come from?

 

[EOC_Jason]

Where did the rollers for the straightener come from?

Google the part # on the wheel and you get this:

https://www.homedepot.com/p/Oatey-3-in-Gripper-Plastic-Mechanical-Test-Plug-33402/100168770

 

[gerryw]

I used 1/2’ copper (60 gallon,7hp comp) installed 20 years ago with no problems.
Used the cheap stuff (L I think) about 50’ of copper, use impact guns, glass bead cabinet, etc.


Very pleased with my set up

Gerry

 

[56Mark]

I did mine in copper. If I was doing it again, copper. Easy, available, cools the air.

 

[Angelfire]

I did mine in Pex-Al-Pex (ie. Maxline equivalent from Rapid-aire). A few observations, recommendations:

-Against my better judgement, I ran this system "in-wall". I wanted copper but just couldn't fathom the cost and there were a few locations that I just wasn't comfortable sweating the joints as I was sure I'd burn the place down.
- The Pex-Al-Pex was installed over the winter and the 3/4" was a bit of a bear to work with as it just didn't want to uncurl etc... I didn't build a straightener as this was all in-wall anyway. But working alone, fishing through the webbed joists was challenging at times....the stuff goes where IT wants to go, not necessarily where you want it to go.
-- Fittings for the Pex-Al-Pex are NOT readily available at reasonable prices. I learned this the hard way just assuming they were relatively easy to find. I found everything I needed but some of them came at a premium. A note here--you can use compression fittings (which I did) or you can fork out $$$ for a crimper and use crimp on fittings. I opted for the compression fittings as I didn't want to spend the money on a crimper. The crimp on fittings seemed to be more plentiful vs. the compression. I'm guessing they are probably better at not leaking down the road but we'll see.
-- I spent quite a bit of time leak checking, re-leak checking, and checking again. I was finally happy when my system held full pressure for 24 hours.
--That being said, after insulation/drywall/etc....I now have a very small leak somewhere. I suspect I bumped a fitting while getting the insulation in so it's there and will be there forever. Hopefully it won't get worse as it only loses a pound or two over a few hours. Not too bothered by that.

Overall, the install wasn't difficult but was a bit frustrating finding the fittings I needed and working with the stuff in the cold. If the fittings start developing leaks down the road, I'll resort to abandoning the system and installing a copper system on the wall.

I did not purchase a set kit. I sourced the Pex-Al-Pex (vs. buying the maxline as it was much more expensive) and the fittings and created my own "kit" if you will.

So if I were to do it again, what would I do? Well, for one, I'd be more careful getting my insulation in I'd probably look at iron more for cost reasons. I gave up on that pretty early as I just don't have any experience threading the stuff. But ultimately, if my current system does **** out, I will probably do copper on the walls. I can sweat copper pretty well and with the increased space and less chance of fire, I wouldn't be worried about doing it.

Hope that helps.
Cheers.

 

[ford33]

I used L grade copper. It's easy to work and parts are available anywhere.

 

[u3b3rg33k]

I did mine in copper. If I was doing it again, copper. Easy, available, cools the air.

out of curiousity - why do you want to cool the air in the lines? doesn't cooling the air cause additional condensation in the lines?

 

[Smoker]

It drops the moisture out so it doesn't end up in your tools.... you want the moisture gone. Air driers are basically refrigeration units that drop the moisture out of the air and dispose of it. For us normal folk that don't want to spend the $$$ on a pro drier system, as the air cools water drops out of the air and runs to the low point, usually (preferably...) the drain on each drop. A nicer filter regulator has a float bowl and auto drain that will do this automatically.

BTW air gets MORE dense the colder it is.