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Pipe Dope Versus Teflon Tape

Eric Commarato

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Feb 22, 2010
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Mississippi
I've used teflon tape to seal air and water pipe joints for many years, but recently started using pipe dope(plumbers pipe compound) and have decided it works better than teflon tape. Which do you prefer and why?
 
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toolfreak

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Jan 8, 2006
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Illinois
When I was a plumber apprentice, my uncle taught me to use both. I wrap the threads with tape, then apply the pipe dope.
 

DonkDonk

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Jul 5, 2010
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Norman, OK
It seems like every time I try to use pipe dope I get a leak somewhere and have to take it all apart and do it over again with teflon tape. I only have experience with air lines (100-140psi). I have never had a failure with teflon tape.
 

Steve_P

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Sep 15, 2010
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like above, i've been burned by pipe dope as well- on a compressed air system, 150 psi. I've had it actually blow out of the joint- I heard a small leak, walked over, and saw a small plug of dope pop out- and then the leak amplified. I re-did most or all with teflon and no issues in years.
 

jstroke

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Oct 17, 2010
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I use loctite 305 or something like that. It's basically pipe dope w/ teflon already in it.
 

bchee

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Texas
Is pipe dope a putty, or the same as this stuff in "stick" form
 

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metal1313

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clinton NJ
depends on the application really, in high pressure uses i prefer tape, but most of the time i use good dope
 

3 at 8

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N. E. Ohio
When I was a plumber apprentice, my uncle taught me to use both. I wrap the threads with tape, then apply the pipe dope.

+2

On water I used to first only use tape thinking less was more; then after it would usually leak I would take off the tape and use only dope, but it could leak as well, and would end up using both. So after the third try I would have success. It's a lot of extra time spent when you consider running up and down stairs twisting on/off shutoffs between applications. Thought for some reason it was wrong to use both. So then I started paying attention to proffesional jobs and noticed that they were using both. So now without blinking twice I use both the first time. For air; tape has allways been sufficient for my stuff.
 
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Tlag

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Jan 17, 2009
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+2
My secret is USE GOOD DOPE!:lol_hitti

Tape is neat and effective, but can get expensive if you have a lot of connections.

++ on Good dope.
And in my experience, you need to let it set-up/cure before applying pressure to air pipes. Some dope sets up more quickly than others. I have some Harvey's that says "Slow Setting" and it is. When I tried to pressure it up right after installing, the pipe joints it would leak. It took 12-24 hours for it to really set up firm.
 

Ditchdigger

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Eugene, Oregon
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Chesterton gold end tape is the only sealant I use. Air lines, Steam lines, heat transfer fluid lines. In my plant my pipes range from 20 degrees Farenheight to 400 degrees and the only leaks I ever get are due to joints expanding when they heat up. With tape I can retighten them. Dope would require complete dissasembly, reapplication and reassembly.
 

Tool Pants

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Oct 4, 2008
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Location
San Jose CA
My friend has been a union plumber for 30 years. He helps me with plumbing projects, which means I stay out of his way. He also uses both. I guess it is something they teach in plumbing school.
 

Skin

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Feb 24, 2010
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Location
Boston
definetly the tfe paste. I hate tape, gave up on it completely. It unravels far too easily and its a huge pain in the *** trying to wrap it tight and rip it when your hands are govered in goop. Also find that it leaked far easier. With the paste its a one shot deal and always works.
 

MrMark

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Jan 25, 2010
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Southern Cal.
It seems like every time I try to use pipe dope I get a leak somewhere and have to take it all apart and do it over again with teflon tape. I only have experience with air lines (100-140psi). I have never had a failure with teflon tape.

dope doesn't seem to work on air lines for some reason.


As stated plumbers use tape and dope on gas and waters. I don't think it is right and it is not recommended by the manufacturers.

I have had a hell of a time getting leak free NPT joints with the new foreign fittings. I solder whenever I can. This is why the plumbers use tape and dope because they don't want to take an NPT job apart. :wtf:

I use just dope on natural gas and make sure I ring it on real tight but you have to make sure that the fitting fits right. If you are running more than 4 threads in and seeing less than 2 threads left it is a good sign there is going to be trouble.

On water, I just use the dope again but I have had to resort to the tape sometimes. The Aussy tape is the best because it is much thinker than the **** on Home Depot. It is called Mill Rose and it comes blue and yellow for gas. The gas is a little thicker, that's all.

But again, use tape for air plug fittings on tools. The dope won't work there.
 

DrkMtnDew

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Sep 24, 2010
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I worked at a carwash for a couple summers doing repairs. on low to moderate pressures teflon tape works really well. on high pressures the tape and dope combo worked best. i never had any luck with dope by itself.
 

MrMark

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Jan 25, 2010
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Southern Cal.
Rectorseal's T PLUS 2. A bit messy, but I've never had a leak - and no galled threads!

After trying a bunch of stuff, this is what I use too. It seems thus far to work well on gas at least. I can tell you from experience that Megalock *****.
 

wellstig1

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Oct 24, 2009
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Location
Torrance, Ca
I use tape up to 1/2" npt. I work with up to 8" npt and we use hercules blue block which is the best our company has found. One warning thing though, it makes it tough to take it off down the road.
 

Hlidskjalf

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Apr 1, 2010
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307
Location
Toronto
As an HVAC tech I always use only pipe dope. I have had experience with low pressure gas, high pressure water, hot, cold... you get the point.

I never had any issues with pipe dope. I also know the plumbers like t-tape and pipe dope combination. I was taught in trade school that pipe dope eats away at t-tape. I never felt the need to use both.

If you are using pipe dope and you got leaks, you're doing it wrong.
 

mrholeshot

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Jun 22, 2010
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I use Teflon tape on air lines and such but on fuel lines and such I use the liquid thread sealer (pipe sealer). On electric fuel pumps where they use pipe threads on inlet and outlet fittings a small peice of teflon tape can cause many problems in a fuel system.
 

Heavy Metal Doctor

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May 26, 2010
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Mason Dixon Line
I think it all depends on the work / parts.
Working on hydraulic and high pressure water systems, liquid teflon thread sealer is what I use 99% of the time and I rearely have any trouble. Cleaning the parts with brake cleaner is the key. For the most part we are not suposed to use tape. This is to avoid the possibilty that a piece of it could tear off and clog a port in a valve / nozzle - which in turn could cause damage / injury. Thread tape is only used for certain specific situations - mostly doctoring up deteriorated low pressure stuff.
 

Chris_PT

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Aug 21, 2010
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269
Location
Shreveport, Louisiana
I use to use pipe dope on all my air lines and even nitrous/fuel lines on my car. I had too many leaks and it was really messy (Im OCD). I've used teflon tape with great success now. :thumbup:
 
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