PEX UV protection is guaranteed for only 90 days .

[Lelandwelds]

The black coil HDPE stock tank pipe is good for years. The outer layer of PE-AL-PE is not UV stable. Nylon is easily dyed. PEX is not water permiable at all so most dyes have no effect. PET fabric has a lye based dye.

Anyone know how to add a UV stable pigment to PEX after manufacture? PEX is nearly perfect for compressed airlines. I can wrap exposed sections with foil tape or something. I can hope red has a better UV resistance than promised. I would love to be able to add a black dye to red pex.

 

[redmondjp]

What are you trying to accomplish? Are you wanting to run PEX on the exterior of the structure? If so, you could run it inside PVC conduit, just to get the UV protection. Keep in mind that the pressure rating of PEX decreases with increasing temperature, and exterior conduits in your climate can get mighty hot inside.

 

[rlitman]

I have a few short pieces that go outdoors, wrapped in foil tape. Like the stubs that come out to feed hose reels and such. You could always sleeve it in the black PE, and just tape the ends that you need to expose for the fittings. That would be much cheaper than PVC, and would flex with the PEX.

Indoors, the UV exposure is not going to hurt PEX. Unless it passes right under a fluorescent lamp or by a window. So, indooes, just sleeve the parts that see DIRECT sunlight (or get within inches of a fluorescent or HID bulb), and don't worry about the rest.

 

[Lelandwelds]

. . . wrapped in foil tape You could always sleeve it in the black PE, and just tape the ends that you need to expose for the fittings. That would be much cheaper than PVC, and would flex with the PEX.

Indoors, the UV exposure is not going to hurt PEX. Unless it passes right under a fluorescent lamp or by a window. So, indooes, just sleeve the parts that see DIRECT sunlight (or get within inches of a fluorescent or HID bulb), and don't worry about the rest.

Yes, you nailed it. I am planning to use it on the interior that has a bunch of polygal window planned. Lexan does not absorb UV .

I like black pipe for the drops. PEX will be super easy for the rest of it. I see outside PEX with no protection in service often. I am sure it will be fine. Another thread claiming his PVC airlines have lasted 20 years made me think about it. I have been searching for a dye method for PEX or UHMWPE off and on for months with no luck.

 

[rlitman]

Lexan made for exterior use will always have a UV protective coating. Otherwise it hazes quickly.

Yeah, I’m not sure you’ll have luck dying PEX. Also, I’m not so sure dye would be helpful. That protects it in depth, but still allows for surface damage. A damaged surface can lead to stress cracking.

 

[jbwilkins]

When I got looking at air distribution for my shop I found PEX wasn’t going to be any cheaper (in fact more) than a Rapid Air Maxline system once I bought the dedicated tools to make the connections.....I doubt I’d ever have much need for the PEX tools again either...

 

[NUTTSGT]

How about some black flexible wire loom to cover the PEX ?

 

[rlitman]

How about some black flexible wire loom to cover the PEX ?

I like that idea. Split loom is easy to slip on, inexpensive, cuts with scissors, and you just electrical tape the exposed ends.

 

[hefnerconstructionlc]

If you have not purchased the material they make a uv resistant pex.

 

[GMCGarage]

The black coil HDPE stock tank pipe is good for years. The outer layer of PE-AL-PE is not UV stable. Nylon is easily dyed. PEX is not water permiable at all so most dyes have no effect. PET fabric has a lye based dye.

Anyone know how to add a UV stable pigment to PEX after manufacture? PEX is nearly perfect for compressed airlines. I can wrap exposed sections with foil tape or something. I can hope red has a better UV resistance than promised. I would love to be able to add a black dye to red pex.

Buy the UV resistant PEX.

 

[HoosierBuddy]

Plastics in general just don't play well with UV. And, they typically don't react well to solvents, so be careful with that dye experiment you're running there.

If I were you, rather than try to reinvent the wheel here, I would just buy the right material (something rated for air and rated for UV exposure) and move on.

Phil

 

[Lelandwelds]

When I got looking at air distribution for my shop I found PEX wasn’t going to be any cheaper (in fact more) than a Rapid Air Maxline system once I bought the dedicated tools to make the connections.....I doubt I’d ever have much need for the PEX tools again either...

You are justifying not buying new tools? Does your daddy know you use his ID to log onto his GJ account?

Add up all the extra fittings. They run the cost up. PEX fittings are pennies.

If you have not purchased the material they make a uv resistant pex.

I got excited about UV resisting PEX until I read the supporting documentation. It is guaranteed for 90 days. Unless you know a different brand?

 

[like2wheel]

You are justifying not buying new tools? Does your husband know you use his ID to log onto his GJ account?

Fixed it for you

 

[jbwilkins]

I’m not into spending money on something I’m going to use once and I don’t have unlimited storage space in my shop.....

$150 for the Max Line kit and nothing else was needed except for a few quick connects, a flex hose from the compressor, and filter regulator, which I would have had to buy for PEX.....


Sent from my iPhone using Tapatalk

 

[shelteredV]

So. Let me get this right. You want to use pex water tubing for compressed air line? um. good luck with that, good idea to put a hazard sign by the entrance to your shop.

 

[Lelandwelds]

So. Let me get this right. You want to use pex water tubing for compressed air line? um. good luck with that, good idea to put a hazard sign by the entrance to your shop.

It fails at, what, 600 psi? I watched an upside down 1.3g mortar explosion contained by PEX without the cross linking. Good oil resistance.

I think it will be my easiest install ever.

 

[Lelandwelds]

Plastics in general just don't play well with UV. And, they typically don't react well to solvents, so be careful with that dye experiment you're running there.

If I were you, rather than try to reinvent the wheel here, I would just buy the right material (something rated for air and rated for UV exposure) and move on.

Phil

There's a UHMWPE product called Marineboard that withstands longterm salt and UV exposure. PEX is so hard to dye because it is impermeable and impervious to water, solvents, strong acid, strong bases, and many oxidizers. The dye can't color if the carrier can't get through. The different manufacturers info conflicts on UV resistance. Some claim superior.

If you use enough unions, black pipe isn't that hard to run. I am still not in a hurry to use a bunch of it. Copper is like crack to a scrapper. I don't want anymore around than the minimum.

Lots of suitable products aren't rated because the expense is too high for an anticipated return.

 

[bad_idea]

I haven't put honest thought to using PEX as air piping before, new idea to me. Can you paint it? That would provide UV protection wouldn't it?

 

[Lelandwelds]

I haven't put honest thought to using PEX as air piping before, new idea to me. Can you paint it? That would provide UV protection wouldn't it?

Nope. It's in the same family as cutting boards and milk jugs. Like all things in chemistry, there are lots of tweaks and variations. Paint won't stick. Dyes won't penetrate. Extremely to mostly resistant to acetone, petroleum products, 30% hydrogen peroxide, strong bases, etc. When it is made, dyes can be added. (They don't offer black.) Oxygen barrier version has an additional layer of plastic, PVA, added. Another has aluminum in the center. There are three different versions of the normal stuff. (I like PEX-B). The hydrostatic design for Bluefin is 630 psi @ 73°F and 400 psi @ 180°F. Working pressure is 160 psi and 100 psi. (Factory likes 4:1 safety margin.)

Many people will not use it because "airline" is an off label use. The big users are water systems so that is what the testing and warranties cover.

Some manufacturers of HDPE make some impressive UV claims. Some say less than perfect UV performance.

I plan using 3/4" black pipe and Chinese 304 SS fittings for each station drop. China black pipe fittings **** but the SS is nice quality. USA black fittings cost more than import SS. A PEX loop would be dead simple easy to install and upgrade. The iron and SS legs can withstand a lot of tugging.

 

[NUTTSGT]

3/4" pipe is alot of air, what are you doing in your shop ?

I swapped out the PVC airlines I had (done at a different time before I knew better and found GJ) for black pipe. I had bought a pipe clamp at a swap meet for $8 and then bought a HF pipe threader for this one job with a 20% coupon. It got the job done and know I have a lot better system than the PVC.

If you're going to do a loop around the shop ceiling/wall and adding drops, that should be a fairly easy project. I had several things to go around that made mine take more time.

 

[ishiboo]

Just because you've dyed it black, even if it were possible, does not mean it would be UV resistant for long-term exposure. You'd have to use a black paint to prevent it from getting to the PEX.

You can't add anything to it to make it UV-resistant after the fact. You can only cover it.

Plenty of PE tubing is UV-resistant. Most PEX is not, especially for long periods. Just use an appropriate material where you are exposed to light.

 

[bczygan]

3/4" pipe is alot of air, what are you doing in your shop ?

I swapped out the PVC airlines I had (done at a different time before I knew better and found GJ) for black pipe. I had bought a pipe clamp at a swap meet for $8 and then bought a HF pipe threader for this one job with a 20% coupon. It got the job done and know I have a lot better system than the PVC.

If you're going to do a loop around the shop ceiling/wall and adding drops, that should be a fairly easy project. I had several things to go around that made mine take more time.

Which pipe threader did you get?

Bill

 

[Lelandwelds]

3/4" pipe is alot of air, what are you doing in your shop ?

I swapped out the PVC airlines I had (done at a different time before I knew better and found GJ) for black pipe. I had bought a pipe clamp at a swap meet for $8 and then bought a HF pipe threader for this one job with a 20% coupon. It got the job done and know I have a lot better system than the PVC.

If you're going to do a loop around the shop ceiling/wall and adding drops, that should be a fairly easy project. I had several things to go around that made mine take more time.

1/2" and 3/4" black pipe are almost the same price. 3/4" doesn't sag as much and can take more yanking. I already have a Rigid pipe threader. Following the roof line, making it look good, and chasing down all the leaks from almost 30 feet in the air is a chore I hope to avoid.

Just because you've dyed it black, even if it were possible, does not mean it would be UV resistant for long-term exposure. You'd have to use a black paint to prevent it from getting to the PEX.

You can't add anything to it to make it UV-resistant after the fact. You can only cover it.

Plenty of PE tubing is UV-resistant. Most PEX is not, especially for long periods. Just use an appropriate material where you are exposed to light.

It is much slicker to have PEX UV resistant everywhere.

Which pipe threader did you get?
.
Bill

Rigid. One from a salvage yard for parts. Another from a closing shop

 

[rlitman]

...Paint won't stick...

Funny thing about that. I've heard accounts of people using large polyethylene plastic drums and containers for outdoor liquid storage. The plastic chalks over time, and after enough time in the sun gets brittle and cracks. But after the initial chalking, it actually holds paint well, and a coat of exterior latex can then greatly extend its service life. However, unfortunately with your PEX example, by the time the surface is damaged enough by UV, the strength is compromised for holding pressure.

OTOH, instead of foil tape, you could wrap it in paper tape, and paint that.

Or again, if this is inside, and not in direct sunlight, just don't sweat it, and just cover the parts that run right under skylights, etc.

 

[NUTTSGT]

Which pipe threader did you get?

Bill

It was the smaller kit, with the hand ratchet style threader. I don't think they carry it anymore. After the discount, I think I had like $30 in it.

 

[NUTTSGT]

1/2" and 3/4" black pipe are almost the same price. 3/4" doesn't sag as much and can take more yanking. I already have a Rigid pipe threader. Following the roof line, making it look good, and chasing down all the leaks from almost 30 feet in the air is a chore I hope to avoid.


Rigid. One from a salvage yard for parts. Another from a closing shop

You have a real pipe threader there. I was I had something like that to use when I was doing mine.


30 ft in the air, holy cow, I hope you have a lift available to use to make the job easier. Wouldn't surprise me that the pipe prices are nearly the same, but I'd bet the difference will be the cost of fittings. I bought mine a handful at a time and when I thought I had everything, I bought the pipe. I prepainted everything first then touched up when finished.

 

[bczygan]

It was the smaller kit, with the hand ratchet style threader. I don't think they carry it anymore. After the discount, I think I had like $30 in it.

This one?

$28 plus tax after 20% coupon.

Bill

 

[NUTTSGT]

This one?

$28 plus tax after 20% coupon.

Bill

Yep, that's it Bill.

Used a 60 grit flap disc to bevel the edge before cutting the threads and an old drill bit to ream the inside of the pipe.

 

[bczygan]

Yep, that's it Bill.

Used a 60 grit flap disc to bevel the edge before cutting the threads and an old drill bit to ream the inside of the pipe.

You're a very bad influence...

You added another item to my tool list!

Bill

 

[NUTTSGT]

You're a very bad influence...

You added another item to my tool list!

Bill

I'm a rebel like that Bill.

 

[Lelandwelds]

You have a real pipe threader there. I was I had something like that to use when I was doing mine.


30 ft in the air, holy cow, I hope you have a lift available to use to make the job easier. Wouldn't surprise me that the pipe prices are nearly the same, but I'd bet the difference will be the cost of fittings. I bought mine a handful at a time and when I thought I had everything, I bought the pipe. I prepainted everything first then touched up when finished.

The cost difference for import black pipe is .40 for tees and .75 for import stainless tees. Even less for close ******* and bushings. Pennies, really, for twice the flow and straighter lines.

The house has 16 ft sidewalls and a 12:12 pitch roof. If I build a 32 x 40 and match the house style, it is about 30 ft at the peak. Heights really bug me so I will probably whittle something down.

PEX will greatly ease the install. I plan on building and leak testing on the ground. I'll use a simple extension ladder to install 10 ft at a time. It will be like putting Xmas lights up.

PEX really opens up some possibilities for trapping any water that makes it past the filter treatment. (As if!) PEX is pretty water resistant so no rusting is expected.