Pipe dope

[Dusty MI]

It used to be that one pipe dope was used for everything, Now it comes in different colors, each color for what was the pipe is going to be used for. Why? Does it really matter?

Dusty

 

[Bob - MI]

Only matters if it leaks.

I agree that we used to be able to use one type but I recently installed a generator at my house and the gas company guy swore by Rectorseal #5 when he installed an upgraded meter. I figure he does this for a living and he must know what works.

I ran about 50 feet of black iron pipe that I cut and threaded myself and had zero leaks using this sealant. Being a machinist back in the day running a pipe threader is pretty straight forward but I had some minor tearing on some of the sections that had me concerned. These were pieces that I bought pre-threaded and had to cut down to fit so I figured there was something different in the material chemistry as opposed to the 22' long full sections that I got from the local mill supply. With some angst I doped the ragged pieces up and reefed them down and happily no leaks.

Take a look at the Rectorseal website.
Rectorseal website

 

[Mike(NEOhio)]

I replaced a line from an LP tank and bought the line from plumbing supply. I knew Teflon tape is a NoNo for natural gas but wasn't sure about LP. The guy gave me Blue Monster, a PTFE based paste. The label says it's good for just about everything except oxygen.

 

[rrlund]

Didn't know that,but guessing it's like PVC pipe. Dad ran a piece of white PVC in a cement slab to run electrical wire through. The inspector condemned it,told him he had to use gray PVC to run electrical wiring.

 

[showcrop]

Teflon tape is fine for natural gas or propane. Like anything else you just have to use the correct one which happens to be yellow.

 

[Butch(OH)]

The Chinese pipe sold at the box stores can be very problematic when threading. Not all of it is bad but at least half is. I had one length of 3/4 that absolutely would not thread without tearing out. Took it back to Lowe's and went back to get a other joint. Told the guy in plumbing and he went into a long winded detail about I didt know how to thread pipe. So I went back up front and convinced the lady to let me take the pipe back to let the guy thtead it. He jammed it in thr machine and ran the threader and handed it back ,"there ya go" there was only one good thread on it. LOL

 

[Janicholson]

Fittings are no better a 1/2" black iron T with the threads on each end 1/8" offset from each other, but at least aligned, but wait, the T opening was 4 degrees out of square with the other 2. All of them in the Kablins Hardware store were about the same. Jim

 

[Russ from MN]

HMMMM, I always understood Teflon tape was not allowed for Natural gas or propane! It's not whether or not it's compatible with the gas, it's the risk of a strand of it coming loose and getting stuck in a safety valve. Then your appliance could leak gas and the house blows up. Not worth the risk for me, there are better, safer sealants.

 

[showcrop]

(quoted from post at 19:55:20 01/02/20) HMMMM, I always understood Teflon tape was not allowed for Natural gas or propane! It's not whether or not it's compatible with the gas, it's the risk of a strand of it coming loose and getting stuck in a safety valve. Then your appliance could leak gas and the house blows up. Not worth the risk for me, there are better, safer sealants.

Russ, you didn't always understand, Teflon tape has been around for only the last 50 years or so, LOL. Check again, The yellow is approved. Where I worked in the early 70s guys were putting the tape too close to the end and little pieces were coming off and causing a check valve to fail to seal. A bulletin came out to use no sealant. People in all trades have to learn many many things to keep from blowing houses up.. Proper tape application is very easy to learn and remember.

 

[Richard G.]

I am like Mike below.
I use Blue Monster on every thing around here.
On the shelf at Lowes.
Richard

 

[Handsome Devil]

Agree with "showcrop". We used both on hydraulic and steam piping back in the 1970s when I worked in a HD job shop environment. Never had a leak with it on steam. But the trick is not to apply tape on the starting threads and make sure you wrap it on the threads in the right direction otherwise it is pounding sand. I did try some newer pipe dope on a recent project when re-plumbing a hyd line but the stuff was recommended for pressure and hyd lines. This was on a compressor and the pressure was not that high in comparison to many machines. No leaks. The can is out in my shop and don't recall the name. Have not used it enough to recommend it anyway. Normally I use teflon tape for all pressure joints I run into. Did some contract work in CT on a railroad, in that shop they used only the thick pipe dope similar to what I tried last summer. Agains I do not think the tape was at fault it was the application in their case? We were running to piping to a large Cummings diesil in a 70 Ton GE locomotive. Their shop their rules so we used the dope. But think the problems were the guys using the tape not having the experience to make it work like it is supposed too? I think the dope really works well but I find it much more messy to use. Regards, John.

 

[Handsome Devil]

Agree with "showcrop". We used both on hydraulic and steam piping back in the 1970s when I worked in a HD job shop environment. Never had a leak with it on steam. But the trick is not to apply tape on the starting threads and make sure you wrap it on the threads in the right direction otherwise it is pounding sand. I did try some newer pipe dope on a recent project when re-plumbing a hyd line but the stuff was recommended for pressure and hyd lines. This was on a compressor and the pressure was not that high in comparison to many machines. No leaks. The can is out in my shop and don't recall the name. Have not used it enough to recommend it anyway. Normally I use teflon tape for all pressure joints I run into. Did some contract work in CT on a railroad, in that shop they used only the thick pipe dope similar to what I tried last summer. Agains I do not think the tape was at fault it was the application in their case? We were running new piping to a large Cummings diesil in a 70 Ton GE locomotive. Their shop their rules so we used the dope. But think the problems were the guys using the tape not having the experience to make it work like it is supposed too? I think the dope really works well but I find it much more messy to use. Regards, John.

 

[Handsome Devil]

Agree with "showcrop". We used both on hydraulic and steam piping back in the 1970s when I worked in a HD job shop environment. Never had a leak with it on steam. But the trick is not to apply tape on the starting threads and make sure you wrap it on the threads in the right direction otherwise it is pounding sand. I did try some newer pipe dope on a recent project when re-plumbing a hyd line but the stuff was recommended for pressure and hyd lines. This was on a compressor and the pressure was not that high in comparison to many machines. No leaks. The can is out in my shop and don't recall the name. Have not used it enough to recommend it anyway. Normally I use teflon tape for all pressure joints I run into. Did some contract work in CT on a railroad, in that shop they used only the thick pipe dope similar to what I tried last summer. Agains I do not think the tape was at fault it was the application in their case? We were running new piping to a large Cummings diesil in a 70 Ton GE locomotive. Their shop their rules so we used the dope. But think the problems were the guys using the tape not having the experience to make it work like it is supposed too? I think the dope really works well but I find it much more messy to use. Regards, John.

 

[Handsome Devil]

Whoops tried to correct some spelling I missed by using back button which I have not tried before. Edit doesn't work for me? Sorry for repeats. Regards, John.

 

[showcrop]

(quoted from post at 10:58:37 01/03/20) Whoops tried to correct some spelling I missed by using back button which I have not tried before. Edit doesn't work for me? Sorry for repeats. Regards, John.

Handsome Devil, no problem I just took it that you agreed with me very strongly.

 

[oldseabee]

I retired from an electric and gas company. I was on the power side but new some of the gas guys
and they gave me some pipe dope for some projects I was doing at home. The stuff was rector seal 5
and it worked great for all my water and lp pipes. Now they use this Key-Tite stuff also, so I use it too,
just as messy but works. The guy that fills my lp tanks gave me a roll of the yellow tape and it works
good too on the lp pipes.As long as they work it's all good.

 

[K Effective]

We're only allowed to use LocTite Pipe Thread Sealant on the primary side piping at work. Other, non-nuclear applications can use other numbers or even tape.

I spend a lot of time in our water treatment plant, recently upgraded. The GE subcontractor used tape on PVC threads, often put on the wrong direction and 15-20 layers thick. More about the craftsman than the tool.