Looking for “Black pipe dope” advice………...

[Runs With Scissors]

Well I plumbed my plasma cutter for air when I first got it, and well……it worked.

But the “black pipe connections” pipes leak a little…..(too much)

My "tooling circumstances" have changed a wee bit, and I have to “re-plumb” it.

I have also decided to plumb the rest of the shop with a series of “air drops” to try and avoid tripping over that damn air hose.

So basically each machine will have a “Curly-Q” air hose so I can reach up/over (haven't decided on height)

I used the standard “white teflon” pipe dope originally, but I was hoping there was something that the “pros” use that will help eliminate the “leaking problem”.

I don’t care if its “paste” or “tape” form…..I just want it to be as leak free as possible.

Any suggestions?

 

[Kennyd4110]

Chinese NPT threads are terrible...I use teflon tape and a paste type dope. Gasiola, Resctorseal, and Blue Monster are all good brands.

 

[Old Machinist]

For fuel or oil application on pipe threads I use Aviation Permatex. I have never had one leak. I don't see why it couldn't be used with air.

 

[John T]

I use Rectorseal 5 (make sure you stir it up) never had a leak with black pipe.

I hate those curly hoses... They sell short lengths of hose with threaded ends... (whips) they work MUCH better than those cheap curlys.

 

[Yooper]

Teflon tape has always been the most reliable way to seal up pipe threads for me. The trick is to use two to three wraps around the thread to give it enough thickness to do its job.

 

[John T]

Also,
I switched everything over to Milton High-Flow fittings.... Love em. I believe they are #760's

 

[Old Machinist]

If you want a hose that is out of the way but accessible get yourself a retractable hose real. The one HF sells has worked great for me for years and the best garage update I ever made.

 

[Tughill Tom]

Megaloc Blue I use it on everything with threads. EZ cleanup and no mess.

 

[chim]

I have a can of Gasoila Softset from 1983 that I'm still using. If it's been a long time since the previous use i give it a quick stir with a screwdriver.

I have some dedicated hydraulic sealant (somewhere), but Gasoila is used everywhere else.

 

[North Idaho Wolfman]

I switched from #5 to this and it works great!

 

[Sidekick]

For tough to seal black iron threads I will pull a couple strands of lampwick (now it's called quick wick I think) and wrap it in a pipe dope like rector seal then insert and tighten.
Here's an example but I think there's a Teflon version now also

Kwick Wick Spools - Wal-Rich Corporation

Manufacturer and master distributor to plumbing, heating, industrial & hardware wholesalers & OEM's nationwide.

wal-rich.com

 

[Russell King]

Not related to the question you asked but…

You may not be turning the pipe fittings the proper number of turns. See these charts but use the TFFT not the torque

Pipe Thread Installation Torque Table Chart

Brass and steel Pipe thread (NPT) installation procedure and torque specification table and chart.

www.engineersedge.com

You might consider using copper tube and sweating the fittings or a kit like this that uses compression fittings.

M7500 RapidAir MaxLine 3/4" Compressed Air Tubing Commercial / Shop Piping Kit - Amazon.com

M7500 RapidAir MaxLine 3/4" Compressed Air Tubing Commercial / Shop Piping Kit - Amazon.com

www.amazon.com

 

[Tarmy]

I have several reels…

Note that all my hoses have Prevost safety fittings. They are great…and make connecting and disconnecting very easy. Look into those while you are at it.

 

[Spam Bot]

I used Rectorseal #3 for decades on black iron pipe. I only use Teflon tape on old threads where the sharp edges have been worn off. In the dark ages, we would wrap cotton sewing thread around the pipe threads, then apply pipe dope to the threaded end and tighten. The cotton would give the added sealing that was sometimes necessary.
I strongly recommend using the Rapid Air piping system. Just make sure that you properly slope it back towards the air supply, and include drop legs to collect any moisture. Take all the drops from the main piping, starting with them pointed towards the ceiling, and use adapters or a pipe-bending tool to create a 180-degree radius back down the wall. This will help to keep moisture out of your drops. I like rejoining the system into a loop with drop legs to bleed off the water about every 15-20 feet along the system. If you are really into having dry air, then set up a series of filters and driers at the compressor end. I don't remember the brand I used on one of my compressors; however, it used a dessicant to dry the air, and when the dessicant turns pink, it is time to put it in the oven to recharge it to its blue state. You can also purchase a refrigerated air dryer system that removes moisture from your tank before it enters your lines. It all depends on how much you want to spend and how much dry air you need. I know that a good dry air system isn't inexpensive, but, like other good tools, the satisfaction of not having to do it over again has a lot of value.

 

[WFM]

I had a plumber here a few yrs back adding a zone of heat to a bedroom. I asked him about Pex being used for air line. He said he had plumbed a whole sawmill locally for air with Pex. I asked him if he had time time plumb my shop and he did. Its worked great since. I personally haven't worked with Pex. But it looks pretty simple if you have the tools.

 

[imarobot]

I had a plumber here a few yrs back adding a zone of heat to a bedroom. I asked him about Pex being used for air line. He said he had plumbed a whole sawmill locally for air with Pex. I asked him if he had time time plumb my shop and he did. Its worked great since. I personally haven't worked with Pex. But it looks pretty simple if you have the tools.

Is pex rated for 100 + psi?

 

[WFM]

No idea.
I have $2.k Quincy compressor that shuts off at 150 psi...I dont run that much to my tools of course. But pex does work.

 

[Dustball]

I had a plumber here a few yrs back adding a zone of heat to a bedroom. I asked him about Pex being used for air line. He said he had plumbed a whole sawmill locally for air with Pex. I asked him if he had time time plumb my shop and he did. Its worked great since. I personally haven't worked with Pex. But it looks pretty simple if you have the tools.

I'm not against PEX for air lines but you'll need to make sure there's a length of piping or hose for several feet in between the tank outlet and where the PEX starts. The heated air at the compressor outlet will reduce the pressure capacity of the PEX due to softening.

If PEX lets go, it'll split and not shatter like PVC piping would (PVC = no good).

 

[Hugo Habicht]

A friend of mine is plumber for the past 40 years. He tested all kinds of material for tapered thread gas pipes. After assembling them he opened the threads and re-tightened. The worst was Teflon tape, liquid sealers were kindof acceptable and by far the best was ..... drumroll here ..... hemp! (used with a type of lube called "Neo-Fermit"). He could open the gas pipe thread the most turns before it leaked and when re-tightening them the leak stopped immediately. Teflon was hopeless, once opened slightly it would never seal again when re-tightened.

 

[JohnDB]

@Runs With Scissors have you checked whether you have NPT and BSPT threads mismatch?