# pipe dope



## mssp (Dec 15, 2009)

Ok so had a discussion with a guy this morning at the shop about pipe dope. He says it is a sealant and I say 
a lubricant. Thoughts?


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## GrtLksPlbr (Aug 12, 2014)

I say it does both, but the sealing properties are what is most important.


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## Burner tech (Oct 24, 2013)

Its both. Pipe dope is any lubricant or sealant that will make a threaded joint leak proof.


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## plumbdrum (Nov 30, 2013)

In theory a tapered thread should seal itself, therefore I think of dope as more of a lubricant. But yes it seals , and I would never not use it. Lol

Sent from my iPhone using PlumbingZone


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## wyrickmech (Mar 16, 2013)

It was a lubricant first then lead paint came along and they figured out that extra property's of the lead helped seal the joint. Then they figured out Teflon and now we have modern thread sealant both lubricant and sealant.


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## mytxplumber (Jul 28, 2013)

*From Wikipedia*

*Pipe dope* is any thread lubricant, thread sealing compound, and anaerobic chemical sealants that are used to make a pipe thread joint leak proof and pressure tight. Although common pipe threads are tapered and therefore will achieve an interference fit during proper assembly, machining and finishing variances usually result in a fit that does not result in 100 percent contact between the mating components. The application of pipe dope prior to assembly will fill the minute voids between the threads, thus making the joint pressure tight. Pipe dope also acts as a lubricant and helps prevent seizing of the mating parts, which can later cause difficulty during disassembly.
An MSDA sheet (See below for reference) reports "Permatex" 51D pipe joint compound to contain kaolin, clay, vegetable oil, rosin, ethanol, etc. The ingredients are designed to a) fill minute spaces between mating pipe fittings (kaolin), and b) serve as a lubricant as the fittings are forced together (vegetable oil).
Various types of pipe dope formulation exist, the appropriate type being determined by the application, e.g., pneumatic, hydraulic, caustic, etc., as well as the expected pressure. Improper selection of the type of pipe dope may result in leakage despite best assembly practices.
Petroleum-based pipe dope is not intended for use on threaded PVC, CPVC or ABS pipe and fittings since it will deteriorate the plastic. Builders in the US are expected to use thread compounds that meet ASTM F2331 - Standard Test Method for Determining Chemical Compatibility of Thread Sealants with Thermoplastic Threaded Pipe and Fittings Materials or thread seal tape on PVC, CPVC and ABS threads.


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## Plumber (Jan 18, 2009)

Lube first, sealant second on most applications. When applicable, I use Monster teflon tape to seal it more better.


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## Nathan901 (Feb 11, 2012)

Anything over 1 inch gets a wrap of gas tape then dope. 
I don't like to think that the dope/tape is what creating the seal, as said before. A properly tightened fitting should be all metal on metal. 

You should be able to unthread a fitting and see the last threads completely clean.


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## Redwood (Sep 8, 2008)

Nathan901 said:


> A properly tightened fitting should be all metal on metal.
> 
> You should be able to unthread a fitting and see the last threads completely clean.


Good luck with that when you check those threads on the 3rd world fittings you've been buying...:laughing:


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## Dpeckplb (Sep 20, 2013)

On brass pressure fittings i use Teflon and pipe dope. On black iron I use locktite.


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## alberteh (Feb 26, 2012)

its a sealant ptfe tape is a loob


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## Coolcanuck (Jan 30, 2012)

I was taught in school that dopes are lube and tape is a sealant, as we were discussing pro dope. According to code book as long as it conforms to UL as a sealant. I like my tape and dope on all water and over 3/4 gas.


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## rockstar (Jul 24, 2014)

blue monster and rectorseal on all my threads! I always dope my compression stops for its lubricating properties


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## Mike Jessome (Aug 7, 2008)

Masters metallic compound enough said


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## Cajunhiker (Dec 14, 2009)

It may be a lubricant but I use it as a sealant. My SOP is any non-flared metal on metal threads without a rubber washer get Teflon AND pipe dope. This equates to no leaks and no worries and successful pressure tests.


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## sparky (Jan 8, 2014)

I use the Teflon tape and green key tight pipe dope on gas lines,way to see if your pipe dope is doing anything or not is to take two fittings and put your dope on the threads and put it together hand tight and leave it overnight,you should have to use wreches or channies to get it loose.this works on the green key tight pipe dope


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## Coolcanuck (Jan 30, 2012)

sparky said:


> I use the Teflon tape and green key tight pipe dope on gas lines,way to see if your pipe dope is doing anything or not is to take two fittings and put your dope on the threads and put it together hand tight and leave it overnight,you should have to use wreches or channies to get it loose.this works on the green key tight pipe dope


That's why I don't like pro dope, I prefer jet lube 60 for my lube, pro dope dries out. When I come back for service, replacing a water heater etc I don't want a struggle pulling things apart or cleaning threads for re-use.


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## Flyguy199 (Sep 20, 2011)

I don't use Teflon tape. I prefer the Oatey pipe dope. Don't like the Blue Monster brand. I also put a little dope on my compression angle stops like someone else posted.


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## wyrickmech (Mar 16, 2013)

The best thread sealant I have ever seen is produced by lock tight it's number is 576 I believe it comes in a tube similar to tooth paste. It is expensive and you don't need much especially when you use Teflon tape first. It was designed for stainless threaded pipe.


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## sparky (Jan 8, 2014)

There's some kind of pipe dope called aircraft pipe dope,they use it on aircraft obviously,but always heard it was some goooooooooood stuff


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## mrjasontgreek (May 21, 2014)

anyone else use leak lock brand? comes in a plain blue bottle. it isn't oil based, and it can be thinned out with alcohol if it dries out


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## Tommy plumber (Feb 19, 2010)

I like the blue and green pipe dopes. But I don't like the blue "Mega Lock".


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## Best Darn Sewer (Dec 23, 2012)

Tommy plumber said:


> I like the blue and green pipe dopes. But I don't like the blue "Mega Lock".


Man, you and me both. I used it for a couple years but the fittings were such a pain to undo if you ever had to amd it balls up easily. I like blue monster tape or good ol' rectorseal #5. I'm sure I am in the minority on Rectorseal, though.


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## sparky (Jan 8, 2014)

Best Darn Sewer said:


> Man, you and me both. I used it for a couple years but the fittings were such a pain to undo if you ever had to amd it balls up easily. I like blue monster tape or good ol' rectorseal #5. I'm sure I am in the minority on Rectorseal, though.


He said he likes the rectumseal,lololololololo:laughing::laughing::laughing::laughin


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## Plumbtastic1 (Jul 5, 2014)

I've started using pro dope. It works great. Wipes clean with a rag and wipes right off your hands just as easy. I have not had a leak yet using it for almost a year (til this comment I'm sure. I'll probably have a nice one tomorrow for jinxing myself) gotta live a little.


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## rjbphd (Feb 5, 2010)

I'm a Rectorseal 5 user as well the Blue monster tape..


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## Nathan901 (Feb 11, 2012)

rjbphd said:


> I'm a Rectorseal 5 user as well the Blue monster tape..


Those colors clash terribly. 
I'd rather my sealants look pretty.


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