PVC Cement for threaded joints?

[surge]

I am curious if you can use pvc cement for threaded joints instead of plumbers tape? The reason I ask is that if an application has pvc female and male threaded parts wouldn't it be ok to use the pvc cement? I could see arguments against it if you are connecting PVC to say galvanized steal or something like that, but from pvc to pvc shouldn't it be ok? Just curious about what you guys think.

Thanks!

[sheshovel]

Pvc cement actualy melts the pvc to form a bond,the reason you would use a application with threads is so you can take it back apart,

so if you want to take it back apart you would want to use teff tape,not glue.

But if you are useing threaded parts you don't EVER want to take back apart or allow anyone ELSE who may come behind you someday to make a repair to take back apart,then go ahead and glue it.

[Wet_Boots]

Why would you glue a threaded PVC connection? Teflon tape is cheap.

[jerryrwm]

Why would you glue a threaded PVC connection? Teflon tape is cheap.

It's almost a guarantee that it won't leak. (chuckle)

[Wet_Boots]

You can't tighten a taped threaded joint so it won't leak? Wimp.

[SprinklerGuy]

Oh...it will leak, maybe not the threaded joint but somewhere else....and boy will someone cuss you for using glue on threads when they go to take it apart. :)

[jerryrwm]

You can't tighten a taped threaded joint so it won't leak? Wimp.

That was said 'tongue in cheek' wasn't it?

[J.Gordon]

I never really cared for Teflon tape that much, I use it sometimes but prefer a product called Rector seal T Plus 2, http://www.rectorseal.com/slnts.htm
This stuff is great in my books!

[kerdog]

I never really cared for Teflon tape that much, I use it sometimes but prefer a product called Rector seal T Plus 2, http://www.rectorseal.com/slnts.htm
This stuff is great in my books!

There is another recent thread dicussing this similar subject. Look at what your pvc fitting manufacturer says about the use of joint compounds. Spears, for example, warns that some compounds/teflon pastes could contain substances that could cause stress cracking to plastic. That statement was written in capital letters in Spears catalog. FWIW......

See ya----kerdog

[surge]

I was just curious if you could do it. I was thinking more along the line of permanently fixing a funny pipe fitting to the main system.

[sheshovel]

Well then your question i answered, i think now dident i.enless you ignore me.

[Wet_Boots]

You can't tighten a taped threaded joint so it won't leak? Wimp.
That was said 'tongue in cheek' wasn't it?
You're right, that might have been a bit harsh. How about "weenie?" :p

(for a swing pipe joint, you can't glue those anyway, because you don't know for sure what the swing fitting is made from. It won't be PVC. Just teflon tape those connections, if you don't like their performance.)

[bicmudpuppy]

It was around 99 or 2000 before I was working for the worst boss I ever had (me). We were having trouble with Hunter SRV valves cracking. Hunters response was the paste we were buying from the plumbing supply had enough lubricating effect to create enough artificial torque to crack the valves. It sounded like BS then and it still does now, BUT I can take 3 wraps of teflon and I can't get a MA more than just past 1/2 into that valve. I can paste it and I can almost bottom it out w/o trying. I like tape. Pap always told me to only tape the joints you don't want to take apart, because you will get to work on the ones you don't. That even includes a wrap or two around unions etc. for me. If it can make your life easier and simpler down the road, how much exta time/cost is there really to it? How many call backs do you have to prevent to justify those pennies worth of tape and seconds of time?

We have some supply guys on here, any manufacturer info stating that Teflon paste is any different than pipe dope? We've been told all our lives in this industry for heads, valves, etc. to "use no dope". I realize the younger generation fail to comprehend the true meaning of this phrase, but does teflon paste really bypass all the negatives of dope?

[Dirty Water]

I use teflon, and a bead of silicon glue. It comes apart easy, and that silicon gives me that extra leak protection just in case.

Haven't had a leak yet.

I don't wrap anything on unions...Thats why they have the chamfered surface (if brass), or the o-ring (if plastic)

[Jason Rose]

I use pipe dope on unions too, steel and plastic. Like said, it makes life easier in the future.

Pipe dope is the only thing good for steel and galvinized fittings, but keep it off of plastic stuff. I have seen how it threads so smooth... yeah, all the way till it bottoms out and still isn't tight. Not cool. It's one of those plumbing points that will be argued till the end of time i suppose... My dad, who knows how to do and fix about everything says teflon tape is crap and that dope is the only thing to use. I say he's wrong. Iv'e tried both and while doped fittings may not leak at first they very well will in the future... Tape is needed to fill the gap due to the lack of taper on the threads.

I see a few applications for gluing threaded fittings. I worked in a greenhouse for about 5 winters and the plumbing in there was always a nightmare. Tight taped threaded fittings could be completely loose and leaking and a few months due to the extremes in temperatures in the greenhouse. Mostly it was when connecting a MA to a brass valve, no glue for that... super glue maybe.
It never mattered who did the plumbing, of how perfect you made every connection, chances are, within a year it was leaking at about 50% of the threaded joints...

[YardPro]

" pipe dope" is NOT TEFLON PASTE is is another type of paste with different chemicals that is generally used with galvanized fittings.

[Planter]

" pipe dope" is NOT TEFLON PASTE is is another type of paste with different chemicals that is generally used with galvanized fittings.

If I remember correctly the problem is with petroleum based dopes. Some of the teflon based stuff is rated for abs and pvc so it can be used. Rector seal-T is ok to use, but I like the tape, less messy.

[bicmudpuppy]

If I remember correctly the problem is with petroleum based dopes. Some of the teflon based stuff is rated for abs and pvc so it can be used. Rector seal-T is ok to use, but I like the tape, less messy.
I didn't think it was a material problem. Even the old Rainbird all metal cans w/ impacts say "use no dope" on them. I always assumed it was the way dope gels/hardens with time. It doesn't become rigid (well, not in the age joints I've had to dig back up), but it gets very stiff. The "use no dope" warnings are on devices w/ moving parts.

[Wet_Boots]

I remember seeing sprinkler heads gummed up from paste-type pipe dope that broke free and flowed to the end of a line. If you visit rectorseal's website, you'll see their listing of compatible materials for their various thread sealants.

I think everyone's mileage will vary depending on what brands of valves and fittings they use. An early combination of manifold tee and zone valve was so loose it took many wraps of teflon tape to be certain the joint wouldn't leak. I still use extra wraps of tape on manifold connections, and leaks are not a factor.

[DGI]

You should be able to get plastic on plastic with teflon tape tight enough by hand.

[sprinkler guy]

Pipe dope reacts to the plastic used by most manufacturers in their valves and sprinklers, breaking down the stability of the plastic, resulting in cracked plastic, usually at the threaded inlet. Most manufacturers will recommend Teflon Paste over tape. Tape has the variable of being put on too thick (do you use 3 wraps, or 5, or 10, etc...) thus causing stress to the female portion of the connection. With paste, no matter how much you put on, the action of threading the fittings together will cause the excess to be pushed out of the connection.

With that said, I'm a tape guy. Spears makes a nice threading past, which is blue in color. That is partly the reason why they recommend you use paste. It's just as messy as Teflon Paste, but does a good job.