Shop Shop air line systems

[Dabbler]

Like any design problem, 'it depends'....

I used to do a lot of home renovations between software contracts - to clear my head mostly. I got to see the negative side of PEX1 and PEX II. Had to replace them with copper. (I don't do PEX - to do it right you have to be an expert IMO)

I've installed new copper into houses with 80 year old copper, and things are still working fine. Some calcium buildup in the old pipes, mind you, and the old stuff is ever so slightly different size, but is easy to work around.

I think you can get away with PEX, if you use the high quality connectors, and only join using junction blocks. Less costly than copper, but more costly than a bare-bones PEX install. If you buy shrouding to prevent UV exposure, you are driving towards copper price quickly...

tough call. Depends on what you can afford.

 

[Chicken lights]

I went compressor to rubber hose to 20' copper, then air/water seperator, then black pipe, back to rubber to go up the wall, then black pipe main the length of the wall. All 3/4" with 1/2" drops, and minimal pipe threading/cutting. I run 1/2" rubber air line after the drops with the larger P fittings, most shops run A's. Runs a 3/4" gun no problem.

 

[slow-poke]

One thing with PEX is it doesn't like UV light. There is some 30-60 day max period it should exposed to direct sunlight. Not usually an issue when its run through walls, but might be in shop if surface mounted and there are lots of windows. Makes it brittle and may crack, but its not suppose to shatter/explode like PVC

I was somewhat concerned about this so I splashed some latex paint on it. FWIW I spoke to a plumber about the UV thing and he stated outside in the sun would be a problem but he said they he has witnessed countess km of PEX in unfinished basements that is doing fine after many years. In my case I ran it along the ceiling with a couple of drops so no direct sunlight.

Time will tell......

 

[Darren]

I've spent the last few hours going over my options, and i've pretty much decided to try out a pex system. Mostly based on speed, future expandability/repairs, I have a bunch of 1/2" pex for the drops, and my neighbor has a shit ton of pex fittings . I'll make up my own puck style manifolds from a chunk of 2.5" 6061 round bar i have leftover.

 

[DavidR8]

I've spent the last few hours going over my options, and i've pretty much decided to try out a pex system. Mostly based on speed, future expandability/repairs, I have a bunch of 1/2" pex for the drops, and my neighbor has a shit ton of pex fittings . I'll make up my own puck style manifolds from a chunk of 2.5" 6061 round bar i have leftover.

I don't think you'll regret the choice. From a value for dollar perspective it's tough to beat.

 

[wmetfab]

Steel pipe gets my vote.
Thats how I did mine in several buildings.
Cheap, easy and oh so rugged.
Dont like black? Use galvanized.
Use pressed metal powder coated stand offs... maybe a dollar each
U have a lathe? Put it in low gear, chuck your pipe, use a coupke stands and get a hand reversible ratchet pipe threader
No need to rent a machine threader.
Dont even bother trying to tread with the lathe, but precut a slight taper dosent have to be perfect use lots of oil Ridgid nu clear or Sulflo #2
Less than 5 mins per thread.
Ive cut 100's of perfect threads like that

 

[mickeyf]

I also have never had trouble with pex water lines. I've renovated a number of houses and have used it for years now. In some cases I ended up replacing old copper which I have always saved and am now using for the air in my smallish shop. I have also never had trouble with shark bit type connectors, other than the fact that they are pricey. The chief advantages of them for me are that 1) you can use them with a cooper pipe that has water in it - you can't reliably do that when soldering, and 2) avoiding having to solder in a low access, tight space, like between the joists in a crawl space is worth the $ for the shark bite.

 

[Tom O]

I don’t like them for water my brother had his ceiling replaced twice so far with leaking plastic pipes as well as those plastic feeder pipes to the toilet.

 

[Susquatch]

The chief advantages of them for me are that 1) you can use them with a cooper pipe that has water in it - you can't reliably do that when soldering,

Just shove a wad of white bread up the pipe before soldering and put a wet cloth around the pipe where the bread is to stop the torch from heating the bread.

Never failed me through 60 years of soldering wet copper.

 

[Chicken lights]

Just shove a wad of white bread up the pipe before soldering and put a wet cloth around the pipe where the bread is to stop the torch from heating the bread.

Never failed me through 60 years of soldering wet copper.

It's 2024 now, it's ok to use brown bread, c'mon

 

[Susquatch]

I my experience, there is a knack to making a PEX crimp. The first dozen or so I attempted had chronic leaks. But then I got better at it and haven't had a problem since. It is so much faster and cheaper that it is hard to go any other way

Been thinking about your experience. Got me to wondering if me and/or my tools are not up to snuff.

My crimper tool (more like a swage tool) came with a nogo/go/nogo gauge which I have used religiously and been mostly unhappy with. Perhaps a caliper would be better?

How do you do yours and what are your thoughts on doing it properly.

 

[Tom Kitta]

I looked into this system some time ago. the 1/2 OD leaves little space ID. I could not find the exact numbers but I think the flow was a bit anemic - something like 10 cfm - but I don't have other specs. On the Amazon website similar is listed for 5hp or smaller compressors.

You can get 3/4 kit - which would be adequate for larger compressor - but price goes up dramatically.

I have a feeling the 1/2 set is for your average small consumer. Max working pressure is under 150 PSI.

This would be ideal for say someone with one of these 3.7hp compressors from PA that are single stage, cheap & in a small garage.

 

[mbond]

Been thinking about your experience. Got me to wondering if me and/or my tools are not up to snuff.

My crimper tool (more like a swage tool) came with a nogo/go/nogo gauge which I have used religiously and been mostly unhappy with. Perhaps a caliper would be better?

How do you do yours and what are your thoughts on doing it properly.

The crimp tool I have came from Rona about 10 years ago. It also came with a go / nogo gauge. I attempted to use it a few times, but the tolerance on the gauge was worse than the tool - it was just stamped metal.

What I have found is that the most important factor is aligning the jaws of the crimp tool as close to perpendicular to the pipe as possible. This is not always easy because usually the pipe comes in coils and has a natural bend. Reverse bending so that is rests straight before crimping has made a big difference for me. Also, I habitually double crimp - but don't triple crimp.

Also, de-burring and slightly flaring the ends have helped (put the crimp ring on first, but the optimal flair is around 3/64"). And I have always used the brass fittings and copper crimp rings. There are cheaper plastic versions of both, but I haven't used them.

Whenever possible, bend the pipe instead of making a joint. Any bend radius over 12" is very safe. 8" is probably the minimum without making a joint

 

[mbond]

The crimp tool I have came from Rona about 10 years ago. It also came with a go / nogo gauge. I attempted to use it a few times, but the tolerance on the gauge was worse than the tool - it was just stamped metal.

What I have found is that the most important factor is aligning the jaws of the crimp tool as close to perpendicular to the pipe as possible. This is not always easy because usually the pipe comes in coils and has a natural bend. Reverse bending so that is rests straight before crimping has made a big difference for me. Also, I habitually double crimp - but don't triple crimp.

Also, de-burring and slightly flaring the ends have helped (put the crimp ring on first, but the optimal flair is around 3/64"). And I have always used the brass fittings and copper crimp rings. There are cheaper plastic versions of both, but I haven't used them.

Whenever possible, bend the pipe instead of making a joint. Any bend radius over 12" is very safe. 8" is probably the minimum without making a joint

 

[mbond]

Of these three joints, only 1 is 'good', but all three passed the 200 PSI air test. The pipe can hold less pressure when it holds hot water

 

[Darren]

Comparing prices of pex supplies on the home depot site vs amazon shows how insane amazons pricing algorithm is. That's a topic for a different thread.

I'm thinking of designing varying height attachment blocks for the run accross the center of my ceiling to set a small slope on the main 3/4" line. Something with a screw to attach to the trusses, and a zip tie to hold the pex into a saddle. These can be 3d printed.

I will be doing sweeping bends rather than 90's

I have two, 2 post automotive hoists. In one shop i setup, I attached the 25' rubber air hose at the top of each of the posts at the ceiling. You could reach the whole car with the hoses and it was one quick loop over a hose hanger at 4' from the floor to hang up the hoses. I will be doing the same here.

Thanks for all your thoughts guys.

 

[Susquatch]

Also, I habitually double crimp - but don't triple crimp.

What does this mean? Apply the crimper twice to the same crimp ring? Or use two crimp rings?

 

[mbond]

What does this mean? Apply the crimper twice to the same crimp ring? Or use two crimp rings?

Apply the crimper twice on a single crimp ring.

 

[Darren]

the barbed section on pex fittings is pretty short, but i wonder if adding a second ring is something that could be done.

 

[mbond]

the barbed section on pex fittings is pretty short, but i wonder if adding a second ring is something that could be done.

I don't think that would be a good idea. The crimp ring relies on the plastic deformation of the pipe to press it into the barbs. Compressing the pipe further back would tend to weaken that bond by splaying the fibers of the plastic I think.

A big part of the strength of this kind of connection is the contained pressure within the pipe itself. Within the 'self gripping' friction angle, more pressure, so long as it doesn't burst or leak through the end, makes the connection at least temporarily stronger. But very high pressure can stretch the material and allow low pressure leaks later