Pencil Zinc Question

[Ron Hill]

Windy : If I'm correct it looks from the picture like the last time that Zn was installed someone use Teflon Tape!!   
That's a NO NO because you want metal to metal contact so the Zn can do it's job!!

A BIG thought

[J_Sail]

You would think it would be a problem, but I did some informal testing on various threaded fittings and in each case the treads cut through the tape and made excellent contact. It's easy enough to test after threading it in, so you may want to run the test yourself to be certain. Just check for continuity between the head and the surrounding metal.

But, since you remove/replace the zinc relatively frequently (so seizing up after being in there for years is not a risk), it may be easier just to use a bit of pipe dope if you are worried and testing with a meter is too much trouble.

Jeremy

[WindyT]

I saw that ron!  Seems like in this case, the Zinc ended up doing its sacrificial duties but did not reinstall the Zn with teflon.  Thanks for the heads up!

[Ken Juul]

The pictures look like the fitting has teflon tape on it.  The zinc has to have a good electrical connection to the HX to work properly.  You should not use Teflon tape on the threads when you reinstall.

[KWKloeber]

Though it's not the recommended practice, use ptfe tape, take on ohm reading.
Then saddle up bareback, take an ohm reading.  You may be surprised.

-k