PVC Conduit to Hide Wires

[Cave Creek Ray]

After three years of house renovation and workshop overhaul, I am in the process of trying to get my garage renovated.

After drywall repairs and painting, I had new garage doors installed. With the new doors came new side-mount openers. The signal wiring between the wall switch and openers for the old openers ended in the middle of the ceiling. I tore it all down and re-wired it.

I have run all wires inside conduit just because it looks so darn clean when you are done. Getting the new tube up amidst the existing tubing would take some thought. One day, while staring at my 1/2" tubing a thought passed through my head: "Why not bent a single tube to run the wiring and make it clean -and cheap." I got out my $9.99 Harbor Freight heat gun and started heating PVC. The aim was to job around the well power line without being too unsightly.

Here is what I ended up with...

It worked out great. I bent 1/2" schedule 40 and, using high temp, heated about a foot of it until it started to droop. That was the sign it was soft. Then, on the floor to keep everything flat, I bent what I needed and then hit the soft area with a wet sponge to harden it back up. Then I rolled it with a base coat of paint before installing it. Then, all that was needed was a quick touch up here and there, like on the brackets.

I have some speaker wire to run and I'll use the same method...

I used conduit for all my electrical wiring and air lines in the workshop and it worked great and looks really nice. (NOTE: Don't custom bend PVC air lines. Glue it up with schedule 40 or 80 if you can get it.)

Ray

 

[Muzzy]

Nice job on the conduit for the door opener!

May want to reconsider the PVC airlines.

 

[matt_i]

(NOTE: Don't custom bend PVC air lines.)

(NOTE: Don't install PVC air lines.)

There, fixed it for ya

 

[MrBalll]

Nice job on the bending. Looks very clean.

 

[Cave Creek Ray]

Matt,

Actually, I had PVC schedule 80 1/2" air lines plumbed through the ceiling in my last house feeding all the pull-down reels. Zero problems in 20 years despite attic temps of 140 degrees. Always kept the drain on the tank seeping (prevents rust and water condensation) so the system bled down in a few hours after I left.

My brother had a BMW/Mercedes repair shop in L.A. for nearly 30 years and he ran Schedule 40 3/4 PVC (UNPAINTED!!!) at 150 psi 24/7 in his shop under bright UV fluorescent lights, with zero problems.

I am running Schedule 80 1/2" air lines in my workshop again to the pull-down reels. I'll paint it (mostly to hide it) but I don't expect any problems.

Ray

 

[LS6 Tommy]

Matt,

Actually, I had PVC schedule 80 1/2" air lines plumbed through the ceiling in my last house feeding all the pull-down reels. Zero problems in 20 years despite attic temps of 140 degrees. Always kept the drain on the tank seeping (prevents rust and water condensation) so the system bled down in a few hours after I left.

My brother had a BMW/Mercedes repair shop in L.A. for nearly 30 years and he ran Schedule 40 3/4 PVC (UNPAINTED!!!) at 150 psi 24/7 in his shop under bright UV fluorescent lights, with zero problems.

I am running Schedule 80 1/2" air lines in my workshop again to the pull-down reels. I'll paint it (mostly to hide it) but I don't expect any problems.

Ray

Don't "expect" good results when the PVC explodes, either...

There's umteem bazillion documented failures of PVC used for air lines. Why are people still in denial about something that is absolutely illegal and very unsafe?

Tommy

 

[Cave Creek Ray]

Perhaps 50 years of use with zero problems?

I had a friend who rebuilds cars. His neighbor, who also re-built cars, had a compressor that was about 15 years old. The neighbor came out, opened up his shop, cranked on his compressor and then decided he needed a cool drink, so he headed back into the kitchen.

My friend was working in his shop with his door open and heard the explosion next door.

The 30-odd gallon compressor tank had detonated due to corrosion issues. Shrapnel was all over his garage. Had the owner been there, he likely would have been killed. After doing some inquiry, my friend found out this is fairly common with older compressor tanks. Yet, we still have them around.
Does that mean we need to install all compressors in an armored room or outside the work area?

Ray

 

[FullRaceMerc]

Clean looking work on the wiring path. Exposed control/sensor wires always look so cheesy.

Most of the PVC success stories I've heard have been from cold climate locations. Enough so that I have come to think that heat is a contributing factor. This is the first I've seen from a warm climate. I have worked in 2 shops where the overhead PVC airlines exploded. Neither installed by me. Both in a warm climate in hot overhead locations. In both places I repaired it multiple times before convincing the boss to swap it out completely. It was sch 40 instead of 80, but I'd still never use PVC for air after seeing those failures.

...Does that mean we need to install all compressors in an armored room or outside the work area?

Ray

Maybe so with old compressors. Tanks work perfectly until they don't. In commercial shops we have had older tanks tested to confirm they were still safe. Probably a good idea for an old home compressor too. Dying is a bad thing.

 

[Stuart in MN]

I've gotten tired of responding to the PVC airline debates, but I'll include links to a few of the dozens and dozens of threads on this topic:

http://www.garagejournal.com/forum/showthread.php?t=34762
http://www.garagejournal.com/forum/showthread.php?t=3930
http://www.garagejournal.com/forum/showthread.php?t=216590
http://www.garagejournal.com/forum/showthread.php?t=69986
http://www.garagejournal.com/forum/showthread.php?t=60109
http://www.garagejournal.com/forum/showthread.php?t=177691

 

[Cave Creek Ray]

Thanks for the info guys. First problems I have heard of.

As for the exploding compressors, I encourage EVERYONE to keep their tank drains ever so lightly cracked to keep the moisture out of the tank. Yeah, you leak a little air but, you expel moisture constantly. (I keep a small plastic margarine cup under the drain to collect moisture.) I also encourage anyone with an inspection port on the bottom of the tank to periodically inspect their tanks interior for corrosion. If you find anything more than surface pitting, consider getting a new compressor.

The accident I mentioned happened in Boulder City, NV. The EMT that responded said they see two or three air tanks explode every year in the Las Vegas area. If that is true, there must be hundreds of these explosions around the country not making the news. Likely some happen while people are at work. I never leave my systems charged unless I am there or will be back shortly and will need it then.

The home inspector that worked my last house sale was a super nit-picker. He clearly saw the compressed air reels in the 5-car garage and the PVC lines that fed them and never commented on them. Guess they haven't gotten the message.

Merc,

My buddy who had the neighbors compressor explode had a compressor somebody gave him. After the accident, his wife got interested in his compressor and its history. All he knew was "it was old and free." She made him cart it to the dump and she had him buy a new one.

Be safe out there.

Ray

 

[matt_i]

This is one reason why an ASME tank can save your life. Its designed with geometry and an alloy that's "leak before break" and will not fast-fracture into a bomb-like explosion. Pinhole, yes, but the material rolled into the tank and its weld process has enough ductility to stop crack propagation that can happen at the speed of sound. Its an obscurity in mechanical engineering, but important, one can read about the epic disasters caused in early 20th century by brittle fracture of tanks.

The el cheapo tanks I don't think are ASME rated.

 

[shillamus]

That technology could come in handy on some hydroponics I am working on.. Thanks for sharing

 

[Cave Creek Ray]

A Kevlar wrap material might be a great business opportunity!

 

[Fishplate]

This is one reason why an ASME tank can save your life. Its designed with geometry and an alloy that's "leak before break" and will not fast-fracture into a bomb-like explosion.

When my 35 year old Craftsman compressor tank failed, it simply started hissing and left a big rusty stain on the concrete below it.

 

[Bib Overalls]

I ran Schedule 80 PVC airlines for a while. I have since replaced with copper. Most PVC air line failures occur at the joints. When I checked the engineering data I found both glued and threaded Schedule 80 joints were marginally stronger than glued Schedule 40 joints. The comfort level I got from the Schedule 80 evaporated.

Compressed air systems are not on the checklist home inspectors use because the lenders are only concerned with structural integrity and safe wiring and mechanical systems. PVC airlines can kill you but a failure will not set the place on fire. I can tell you from experience that OSHA inspectors will write up PVC airlines every time.