Glue area DOES make a difference, and the larger the pipe, the less glue area/cu of volume (I forgot to mention I worked in engineering jobs in manufacturing for 11 yrs). And, as PVC is petroleum based, oil does act like a solvent. Another key factor in PVC is the larger piles (3" & up) are usually foam core (two thin walls of PVC with a foam filler between), which further reduces their ultimate strength. A good filter prior to the PVC piping will take care of possible oil contamination - and woodworkers don't want oil in the shop air anyway. The systems I have seen used successfully have been up to 1 1/2". And, unless you are sandblasting (not much of that in woodworking), a 3/4" line will handle all the airflow you could possibly need in a small shop, but unless your shop is small I wouldn't run anything less that 1/2". When you double the diameter of a pipe, you quadruple the area, so a 1/2" line handles twice the volume of a 3/8", and a 3/4 handles four times as much.

Pay attention to the pressure settings on your compressor. Many of the larger home shop units now can hit 150 psi (mine does) where the older standard was 90-110 psi, and the most you should need in a woodworking shop will be 80-90 psi. There is a pesky little issue know as pressure loss in air (and water) systems and the can come into play with nail guns & painting equipment. Standard rubber air hoses are 3/8" ID. The light, snag-free and coil units are usually 1/4" ID. The place for these in any system is the last segment going to the tool, and the longer it is, the more pressure loss you have. Trim and brad guns don't take much in the way of pressure or cfm (unless you are working with Maple or Oak), but other air tools (sanders, drills, impact guns and paint guns) can chew up a lot. Check the labels on your tools before you size your lines, no matter what type of piping you are running.

And Grandpa, you've got me curious. I have some Pex and the tools to work with it. I'll see if I can scrounge up the right fittings to make a test line section. I'll run it out the back door of the shop and crank up the pressure (my compressor goes to 155) and see what happens. I'll let ya know!

 

Here is A link that may just solve your air problems. http://www.rapidairproducts.com/

 

Dave, I will be looking for your test on PEX and compressed air. I have a big roll of PEX in 1" that was given to me so I am most interested. I read up the line where someone thought it was more costly than copper but I don't think it is in my area. Copper is really expensive here. You would think those items would be the same nation wide. At least within a narrow range. The Rapidaire system just looks like PEX but who knows what it is made from. All yellow glue isn't the same is it? LOL Thanks for the response. Steel pipe may still the the best answer for air. They will cut it and stread it at my ACE store. Just give them the dimensions and they handle it. I buy new black pipe from them for clamps and tell them how I want it made up. Thanks again.
Oh, yes someone originally asked about copper fitting that came with solder already in them. I have limited experience with them but have used them. I was really not want to use them but they were all I could get. I used probably 8 or 10 fittings and they worked great for me. I just cleaned the tubing as usual and wiped with flux then put the fitting on and applied heat. It held leak proof first time with no problems.

 

My choices would be either copper or nylon. Steel is good, but rust is the problem. The cheapest possible system is rubber hose, but may not give long life, and with it's low cost, can be replaced many times without breaking the bank.

 

My understanding that the RapidAire hose material is nylon…

 

At one time or another I've had shops set up with PVC, Iron and copper.

PVC, as many others have noted, can be very dangerous; the pipe is not designed to be used with air and has integrity issues with changes in temperature and any exposure to sunlight.

Iron was safe and secure but had several issues: it was a pain to install because we had to thread almost every joint and after about six months started to become a maintenance nightmare as the rust in the lines started causing issues with my machines. Even just using the blow guns was messy with all of the rusty spray going everywhere.

Copper is what I had in my last shop and overall was a good system; secure, safe and while not maintenance free (there were some electrolysis issues) it was a solid system. The only negative things about it were: it was very expensive! That copper's not cheap and while easier than iron to install it still took a long time to sweat all the joints.

I built a new, and hopefully last, shop a couple years ago and used a new aluminum pipe system that i wish had been available back when i did my first shop. It has all the "pros" and none of the "cons" of every other system I've used. It is safe and secure, extremely easy to install (it took a helper and myself less than a day to install air completely throughout my 8000sqft shop), to date I've not had any maintenance or contamination issues, and best of all it was inexpensive - especially compared to copper!

If you want to see any pictures of my latest (last, if I have anything to say about it) shop let me know and I'll shoot you a couple. Here is the place where I purchased my system http://www.speedsourceusa.com/prevost-air-systems.html - They were easy to work with and helped me out with the design layout a lot.

So to boil it all down I'd say no to PVC and Iron and yes to either Copper or Aluminum.

 

Just go ahead and use copper. BUT--don't worry about sweating the joints. Use this product: http://www.justforcopper.com/ I have been had it in use for almost 6 years, under pressure constantly, both water and air systems. NO problems. Just read the directions and do what they say. It really is that easy.

 

Also please connect a ball valve to the drain plug opening on the compressor with a length of galvanized pipe.
You will have to remove the pipe plug to do this, then remember to open the valve at least once a week, or
every morning if you are using the compressor a lot, this will blow out the moisture accumulating in the tank,
make your tank last longer and eliminate some moisture before it even gets to your air lines.