Can soldering destroy pipe dope and teflon tapes?

[MiamiCuse]

I have a all brass shower valve that has four threaded ports.

I have used a brass male adaptor with one threaded end and one socket end. I used pipe dope and teflon tape to thread into each port, then I plan to solder the other end to copper pipes.

The male adaptor is only about 2" long. If I solder one end to a copper pipe, I will have to heat up that fitting, and the adaptor being so short, the high heat will be transfer to the other end and I wonder if it will mess up the pipe dope and teflon tape...and may cause it to leak?

Is this concern valid?

Thanks,

MC

[Handplanes]

Drape a moist rag over the shower body where you don't want the heat. Use a MAPP torch to heat the fitting quickly, then wipe down the joint with a moist rag after waiting a few seconds.

[EXT]

Yes, it can destroy the dope and/or teflon tape as well as any sensitive seals, temperature compensators and plastic inside the brass body.

Solder the pipe and fittings together so that you have several inches of copper pipe, THEN thread the threaded end into the brass body. Once you have prefabed each of the four pipe lengths and attached them to the valve, then install it in the wall. Sometimes you can support the valve body by inserting the side hot/cold pipes through holes in the studs and then threading them into the body.

[BobK207]

Is this concern valid?

Handplanes suggestion will work..... I was concerned as you are about tape & dope survival but using HP's method I have soldered "near" tape & dope with no leaks.

btw brass is not nearly the heat conductor that brass is....so heat the end to be soldered quickly & have "no worries"

cheers Bob

[David Nebenzahl]

On 2/2/2009 7:53 PM MiamiCuse spake thus:

One question, a little off your topic: why use both teflon tape and pipe dope? Seems like teflon alone ought to be good enough.

[Ernie Willson]

I don't know if it is still true, but it used to be that Teflon vapor was highly poisonous. This may no longer be true...I just don't know. I'd really think twice about heating Teflon tape up to a temperature that melts solder.

EJ > I have a all brass shower valve that has four threaded ports.

[Michael Dobony]

They do NOT work together. Use one or the other. I personally prefer the tape over the dope. Unless you are using the non-drying teflon dope, the dope tends to harden and crack and leak and is a nightmare to pull apart later if needed.

[nefletch]

I disagree. I have been using tape and dope for over 20 years, and I never have a leak. And yes, I am a plumber, so I do use this on a weekly basis....

[Michael Dobony]

I would not be hiring you for any plumbing work.

[Frank]

Fumes from pyrolyzed Teflon are dangerous to humans as they can cause "polymer fume fever" or flu like symptoms which go away with time. Birds like canaries are very susceptible because of their high respiration requirements and can succumb to fumes from burnt Teflon fry pans. Teflon does not degrade much below 400 deg. F so it should be OK to solder a short distance away if solder joint is not overheated.

[MiamiCuse]

I have read that you use one or the other.

However, after researching this a bit over the net, this turned out to be a subject that has been bought up numerous times on various plumbing forums and threads and the overwhelming majority of the plumbers says they used both. This is why I use both.

MC

[BobK207]

the overwhelming majority of the plumbers says they used

My dad showed me use of pipe dope in the 50's ...we switched to tape in the 60's

I switched to Teflon dope (80's) only after a plumber doing work for me suggested it.

I used it until another plumber suggested both & now that's what I use.

I guess the bottomline is ....any product (or combo) will work if the joints are made up properly.

But for some reason I seem to like "use both"

I cannot remember the last threaded joint that leaked.......solder is a different story.

cheers Bob

[nefletch]

There's an old saying that rings true in your case. Some customers you just don't want.

[Handplanes]

Because someone says they use a different technique you imply their work is sketchy? Seems a bit harsh viewed from the cheap seats - and unwarranted.

There is no problem with using both tape and dope. Many plumbers use both tape and dope on all fittings, some just use both on sketchy joints, and others don't think it's necessary to use both. There's no prohibition.