Pipe threads

[NYSail]

So I replaced my hot water heater last season and added the threaded to hose barb fittings for the heat exchanger. Typically I do a couple wraps of Teflon tape and all good. However seems one of the fittings is leaking coolant from the threads. Will be redoing but just wanted to get feedback on what most use.... pipe dope, Teflon tape or both.

Thanks
Greg

 

[Peggie Hall HeadMistress]

I'd use Teflon tape, just a lot more than you previously used.

--Peggie

 

[dlochner]

Are the threads compatible, meaning are both straight or tapered? If the threads are mismatched, it will feel like the fittings are tight enough, but they will still leak especially under pressure.

 

[Peggie Hall HeadMistress]

Good point! Also...be careful NOT to OVER-tighten fittings in an attempt to prevent or stop a leak...that can actually make the leak worse and will crack a plastic female fitting.

--Peggie

 

[NYSail]

Yes... fittings are the same. Not over tightened. Saw a video where the guy uses Teflon tape putting into the groves only.

Anyway, guess I had just a bad wrap.

Thanks
Greg

 

[JoeWhite]

Assuming your threads match, I wrap 8 turns of pipe tape then wipe the above paste on both surfaces, then wait 10 minutes then put them together.

 

[sesmith]

When it comes to pipe thread fittings I've always found that teflon tape usually works great on new stuff and pipe dope works best on old stuff.

 

[NYSail]

Thanks!

 

[dlochner]

Another option is using yellow teflon tape. This is designed for gas piping and is a bit thicker than regular white tape.

 

[RoyS]

The best plumber I know uses both on every joint.

 

[jssailem]

Pipe Thread.. Pipe dope