Linked Questions

12 votes
12 answers
131k views

What goes on threads first: tape or dope?

Should the dope be applied directly to the male threads or should the tape go on first?
Matthew's user avatar
  • 9,867
9 votes
6 answers
117k views

Prevent air leaking from couplings on an air compressor hose

I recently purchased an air compressor. When I turn it on without a hose attached, it seems to work fine. It gets up to 140 PSI and shuts off the motor. As soon as I attach the hose, I can't get ...
Stephen Ostermiller's user avatar
19 votes
2 answers
71k views

When is pipe dope/tape needed?

When is it appropriate to use tape, dope, or nothing at all when connecting pipe fittings? Several advised not to use any product when I posed this question. What is the purpose of each product, and ...
glenviewjeff's user avatar
  • 1,450
8 votes
2 answers
62k views

Can you disconnect and reconnect a gas flex pipe?

I installed a new dryer last week and, in doing so, purchases a new flex pipe as they say you should never re-use the old one. I now need to make some adjustments to the flooring so need to pull the ...
DA01's user avatar
  • 24.3k
3 votes
2 answers
31k views

Should I use Teflon tape or pipe dope when connecting PVC to metal?

I am in the process of repairing PVC pipe, which was broken due to freezing. I'll be connecting the PVC pipe to a metal check valve. Should I use Teflon tape or pipe dope when connecting PVC to metal?...
Chad's user avatar
  • 31
1 vote
3 answers
19k views

PVC to metal joint leaking

Some days ago I assembled the following joint using pipe dope (it is solvent based that semi hardens to a rubber like stuff). I waited 2 days to pressurise the system and after a few days it started ...
Luiz Borges's user avatar
  • 2,325
2 votes
2 answers
37k views

How should I connect nipples to a hot water heater?

I recently installed my new hot water heater. I know nothing about plumbing and my installation procedure was informed only by sketchy home depot employees and youtube. One of the issues I'm having ...
chad's user avatar
  • 235
1 vote
3 answers
3k views

Does thread compound (dope) over tape prevent this kind of leak?

When applying pipe joint compound, a.k.a dope, does the application of tape (Teflon tape etc...) not hinder a chemical bond between the compound and the threads, or is does the compound merely serve ...
P2000's user avatar
  • 16k
1 vote
1 answer
4k views

Can pipe dope be used on water lines in a vanity

Does it hurt if I use pipe dope on water lines connecting a faucet in a vanity?
Joe P.'s user avatar
  • 11
1 vote
3 answers
209 views

Leakage in my pipes, how to densify/seal?

I've never built with pipes before so maybe I'd need some general advice regarding leakage. On a specific note, I've built a system (see picture) where it leaks practically everywhere. I've sealed it ...
Lennart's user avatar
  • 137