# Teflon tape or pipe dope



## Ron The Plumber

Tape should be used when dealing with plastic fitting mainly plastic male thread water fitting, reason being if you use pipe dope on plastic male threaded fitting for water supply, the dope tends to make the threads too slick causing overtighting of the fitting.

Now on plactis drainage fitting, pipe dope if fine to use.

Now we use a combo of teflon tape with pipe dope on all metalic male water fitting and pipe, this ensures it will have a possitive seal each and evreytime.


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## carlfino

Have you ever found situations where pipe dope caused any kind of chemical reaction with a plastic component that led to the part failing?


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## Ron The Plumber

Nope not in 25 years.


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## mdshunk

Consequently, Rectorseal #5 is the shizzle as far as pipe dopes go!


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## Ron The Plumber

We never use Rectorseal


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## fqp25

Regular old Teflon tape should not be used on gas piping. They do make a tape for gas pipe but it is more expensive than pipe dope. 

Good old slic-tight pipe dope for me. but I know it's getting harder & harder find.


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## Ron The Plumber

We use Megaloc on gas pipe no tape

Teflon tape with pipe dope on brass fitting.

Teflon tape on plastic water fittings male thread adaptors

Megaloc or teflon tape on plastic male threaded drainage fittings.


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## majakdragon

I use teflon tape on most joints under 2" except gaslines. I don't even trust the yellow tape for gas. Over that size , pipe dope. I believe Rectorseal #5 is probably the best pipe dope compound around since I haven't seen Key Tite in quite a while. One thing about teflon tape though. Don't buy that $.39 junk stuff off the bargain bin shelf. I have seen some that was so thick, you couldn't even get it to stick to the threads.


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## Guest

*Pvc To Metal*

Which is best for transitioning from a threaded PVC to metal connection, teflon tape or plumbers thread compound?


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## Ron The Plumber

Teflon Tape if it's a water fitting, pipe dope if a drainage fitting.


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## Double A

Read the label. The label will tell you what you can use it on.

Rectorseal #5 is an oil solvent based product and will attack and weaken ABS plastics. Rectorseal T+2 is safe for ABS plastics as is Hercules Megaloc.

When using teflon tape, be careful with plastics. You can put too much on the male threads and when screwed into a plastic female fitting you can cause great pressure in the fitting and it will fail. Rule of thumb is, two wraps max. More is not better.


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## winkydink

*I saw no one mention the liquid Teflon.
Yet I see many plumbers using it. 
Not sure which they are using it on.

Also when (what type of connections) should have NO tape or dope or liquid Teflon ?

thanks
*
*wink* :wink:

:euro:


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## Ron The Plumber

winkydink said:


> *
> Also when (what type of connections) should have NO tape or dope or liquid Teflon ?
> 
> thanks
> *
> *wink* :wink:
> 
> :euro:


On compression joints, but sometime I will use pipe dope at the point of seal on a compression joint if it's brass. But it's not needed.


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## paulm

*Rectorseal and diesel fuel*



mdshunk said:


> Consequently, Rectorseal #5 is the shizzle as far as pipe dopes go!


'Shizzle' is new to me, I don't know if that's good or bad... 

I'm trying to seal against off-road diesel fuel. Before you say 'Diesel fuel is diesel fuel,' let me tell you that it is NOT. The dye in off-road diesel attacks a lot of thread dopes. Rectorseal tells me NOT to use #5, but rather to use #7. Other manufacturers say, "Diesel is diesel." Anybody have experience with plumbing for off-road diesel fuel?

Paul in WI


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## bigMikeB

Teflon tape was originally meant to replace wicking.

I use teflon tape on plastic pipe fittings.

Teflon with (Hercules)pipe joint compound on brass to brass.

Teflon with Pro dope on copper to metal fittings.

Grip on gas lines over 3/4".

Leak lock on refrigerent or oil piping.

X-pando on large piping (ie boilers).

Teflon paste or Megaloc on small gas piping

If you read the Rector seal can you will see it is supposed to be left to set for a while before pressure is applied. 

Often the specs on a job specify what dope is to be used on what piping.

I am a United Association pipefitter for over 20 years and have seen many trends come and go but there are some old hold outs.


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## That one Guy

To much pipe dope on a gas line will get inside the pipe and spread out like a spider web.


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## Jack Hass

Do you guys use teflon tape on pvc fittings no matter what, or do you wait until it leaks and then use it?

Is Teflon tape on pvc joints a requirement?


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## bigMikeB

*Always*

Any pipe joint needs some type of thread sealant. So, yes
always use it on plastic threads.


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## Ron The Plumber

Use teflon tape always on plactic male threads when dealing with water.


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## Longtooth

Teflon tape increases the OD of the male fitting, too much will crack a plastic fitting (fmoe) . I prefer dope with teflon. I recently read (from a reliable source) to only use dope on 3/4 of the male thread, the rest will fill in and not get to the inside of the pipe. I'm a mechanic, not a plumber, so sue me if I'm wrong.
:laughing:


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## Ron The Plumber

Pipe dope in the male thread water only, will make it too slick, too slick will cause you to overtighten, take it from a pro in the field.


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## bigMikeB

*Ron the plumber,Water only?*

What do you use on male threads when it isn't water? And what else do you use plastic pipe for?


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## Ron The Plumber

I'll use pipe dope on dwv fittings, male adaptors, Clean out plugs, sometimes I'll use a them both, dope over the top of tape. When combined tape and dope will use on both dwv and plastis water pipe, but never dope alone on water pipe male threads.


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## Longtooth

Ron The Plumber said:


> I'll use pipe dope on dwv fittings, male adaptors, Clean out plugs, sometimes I'll use a them both, dope over the top of tape. When combined tape and dope will use on both dwv and plastis water pipe, but never dope alone on water pipe male threads.


Never heard of using both. You sound like a hella good plumber. :thumbsup:


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## rolldodge

Interesting info guys, thanks. my question ... i am putting a manifold together for my air compressor, combination for brass and gal steel. Will pipe dope and teflon work w/this application?

thx


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## Ron The Plumber

For air compressor use tape only, don't use pipe dope.


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## steve771

Just wanted to say 'thanks' for the idea of using teflon tape and also pipe dope on a water connection. I just could get a consistent seal with just tape, and the pipe dope seems to have made the difference (well, so far!).


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## comp1911

I didn't use tape, dope only on most of the threaded connections in my house when I built. I ended up redoing them with teflon tape as most of them leaked. Lesson learned.

Teflon dope on LP pipe. I used teflon tape on my PVC cleanout caps.


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## KUIPORNG

*another example*



comp1911 said:


> I didn't use tape, dope only on most of the threaded connections in my house when I built. I ended up redoing them with teflon tape as most of them leaked. Lesson learned.
> 
> Teflon dope on LP pipe. I used teflon tape on my PVC cleanout caps.


Agree... Another example of company trying new invention on convention items for making bucks...

go with what is working and stay with tradition is a good idea most of the times.


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## MechanicalDVR

I like leak lock on LP lines, it seals and locks the joint up from any vibration.


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## RippySkippy

Ron The Plumber said:


> ...Now we use a combo of teflon tape with pipe dope on all metalic male water fitting and pipe, this ensures it will have a possitive seal each and evreytime.


Ron, you don't know how much time you saved me...I just plumbed a Weil McLain system, and decided to try this on the treaded fittings and man, that the cats...not a single leak. You 'da man! (that's a good thing!)


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## Ron The Plumber

Yep, I hate having to take pipes apart do to a leak, I like to do it one time and one time only.


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## curt364

Should I use tape or dope on a hydraulic oil pressure connection?
The connection is galv. pipe to control valve.


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## Ron The Plumber

Good question.


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## curt364

Thanks Ron:wink:


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## DIY Guy

Ron the Plumber, 
You said: "Now we use a combo of teflon tape with pipe dope on all metalic male water fitting and pipe, this ensures it will have a possitive seal each and evreytime."
What is the method for this on brass water connection? Dope on male thread and then wrap it in tape?

Thanks,
William


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## Ron The Plumber

DIY Guy said:


> Ron the Plumber,
> You said: "Now we use a combo of teflon tape with pipe dope on all metalic male water fitting and pipe, this ensures it will have a possitive seal each and evreytime."
> What is the method for this on brass water connection? Dope on male thread and then wrap it in tape?
> 
> Thanks,
> William


Wrap with tape and apply pipe dope on top of the tape.


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## DIY Guy

Thanks Ron.


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## plumber Jim

I Agree with Ron, I always use teflon tape with megaloc on my metal water lines and i couldn't tell you the last time i had a leak because of doing it that way.


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## Alan

Ron The Plumber said:


> On compression joints, but sometime I will use pipe dope at the point of seal on a compression joint if it's brass. But it's not needed.


Also any threads that actually seal via a gasket or O ring shouldn't need any tape or dope IE : Stainless flex supplies, WH flexes......


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## Alan

Ron The Plumber said:


> Wrap with tape and apply pipe dope on top of the tape.


 
We're actually told the opposite over here...... if you're using both, the female threads of the fitting should have tape in them.....:huh: :whistling2:


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## Ron The Plumber

Alan said:


> the female threads of the fitting should have tape in them.....:huh: :whistling2:


I see what your saying, it does not matter which way you apply it, they both serve the same purpose. I find it easier to apply the pipe dope after the tape, keeps my fingers clean. 

But do as your told.


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## Alan

Ron The Plumber said:


> I see what your saying, it does not matter which way you apply it, they both serve the same purpose.


I agree wholeheartedly, although I think that I prefer to just omit the 'goop' altogether whenever possible.


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## tsansone

HELP !! I made a clasic weekend warior mistake. While installing a gas grill over the weekend I used a dope product on a brass to brass connection which (now that I read the instructions) is really meant for CPVC piping. The product is called real-tuff. Will this connection be ok as is or must I redo with a differnt dope?
Thanks.


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## Alan

tsansone said:


> HELP !! I made a clasic weekend warior mistake. While installing a gas grill over the weekend I used a dope product on a brass to brass connection which (now that I read the instructions) is really meant for CPVC piping. The product is called real-tuff. Will this connection be ok as is or must I redo with a differnt dope?
> Thanks.


Interesting... I see on the can it lists CPVC pipe and fittings on the front.... is that the only material it lists? Perhaps this is one of the few 'dopes' that is safe to use on CPVC ? 

Anyway, here is a list I found of some tape and dope products (including real tuff) and their uses listed...

http://www.herchem.com/products/thread_sealants.html


"
*real tuff™*

A multi-purpose thread sealant formulated with the highest percentage PTFE content on the market. PTFE particles fill cracks and tiny thread imperfections - providing superior lubricating and sealing properties. Leak-free joints can be tested and put into service immediately. Holds tight against vibration, expansion, and contraction. Brushable; non-separating; will not run or drip from joints. Soft set; no cure time required. Withstands temperatures from -50ºF to 500ºF (on steel pipe), and pressures of 12,000 psi (hydraulic), 2600 psi (gas). For use with liquids, including acids and alkalis and gases (except oxygen). For use on metals, including galvanized steel, black iron, aluminum, copper, brass, stainless steel and on PVC, ABS, and CPVC plastics (for use on specific brands of CPVC pipe, verify suitability with pipe manufacturer). Superior anti-galling properties with stainless steel. Excellent resistance to strong acids, alkalis and ketones. Non-flammable and contains no heavy metals or volatile solvents. Certified to ANSI/NSF Standard 61, safe for drinking water lines. Meets Fed. Spec. TT-S-1732. White.
"


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## frankinzaz

*pipe dopes in spain*

we installed 70 meters of 2 inch galvanized pipe to connecct with a community irrigation system in spain. when i returned from buying the pipe and supplies, i saw they had sold me black polyurethane paint instead of pipe dope. the neighbor told me "sure, thats how we do it here. wrap the threads with fine hemp material and paint it". i'm from usa and it seemed wrong to me, but then i thought maybe its the local way and i'm learning a new way to do things. the next day i asked at a diiferent hardware store and they also were going to sell me polyrurethane paint. a few days later, the coop's plumber came to install the meter, used automobile grease as pipe dope, and told me if we ever had a problem with the painted threads, they'd break since the paint had hardened over the hemp. another example of how "spain in different". what do plumbers think of this? :wallbash:


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## buzz

*Pipe tape thickness*



Ron The Plumber said:


> I see what your saying, it does not matter which way you apply it, they both serve the same purpose. I find it easier to apply the pipe dope after the tape, keeps my fingers clean.
> 
> But do as your told.


 
I definately agree with your process. I have been using it for a while myself with great success. Tape by itself, or dope by itself, never seems to work. The question I have for you is what tape to use? Up till now I have been buying the cheap bags of tape rolls at the depot. They seem very thin. But I understand that there are varying thicknesses that you can buy, that are all color coded based on thickness. But isn't a few more raps of the thin stuff identical to a few wraps of the thick stuff? Cost isn't an issue, and I prefer to buy the right stuff. It just seemed like all the tape I saw out there was pretty much the same.


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## geoffleach

*nylon to brass and pvc*

I'm connecting a pressurizing pump (brass, female, 1/2") to a filter (Culligan, pvc, 3/4") using nylon malel-to-barbed fittings on either end of a 16" piece of reinforced pvc tubing. The setup is provided by the pump's mfg. After considerable experimentation, what seems to work best is to start wrapping teflon tape on the first threads and to move in a spiral towards the other end, finishing with about three turns there, actually overlapping the hex end. Installation is completed with a stainless band clamp on the barbed section. 

Problem is that there remains a small drip at the pump end.

In all of the experiments, the condition of the threads on the nylon fittings appears to be good. There has been no cross-threading (as yet).

FWIW, when I have removed the fitting, on previous attempts with _less_ tape, pretty much all of the tape has vanished.

So, this seems to contradict the relevant postings here. I'd appreciate comments or suggestions.


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## allencj

I know how to change a shower head but am having real trouble getting the old head off. It was originally put on by a plumber and he used some sort of liquid teflon I think. It looks brownish/yellow. The head seems to be really stuck on and won't even budge. I'm afraid that if I put any more pressure on it I could break the pipe. Whatever he used - is it like glue or do I just really have to put more pressure on my wrench?


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## tman17m

been lurking here for a while, thanks for all of the advice / opinions everyone. I thought Id throw in my 2 cents on this issue... just finished a plumbing project on my house. 

The water main from the street is 1", goes through a 1" gate valve then through the 5/8" water meter. After the meter there is a pressure regulator, then a 1/2" ball valve, then 1/2" copper leading through the house.

I replaced everything after the pressure regulator with 3/4"... 3/4" threaded brass ball valve, then a 3/4" brass fitting to connect with the 3/4" threaded copper to copper pipe fitting. Needless to say there were a lot of threaded fittings I had to deal with.

I left all of the threaded fittings downstream of the pressure regulator intact, they were not leaking or causing me any problems. On all of the new fittings, I first put 3 tight wraps of teflon tape around the whole joint, then used pipe dope on top of the tape. Tightened down the fittings...no leaks! It seems like the assembly of the fittings squeezed out a lot of the pipe dope, but I dont have a problem with that...it wipes up easily.


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