I just installed a new expansion tank. New copper female fitting as well. After installing I get a small wicking of water at the connection....
if any, how many wraps of Teflon should I use for this.

I did it a few times and always had a bit of water coming from the threads.

Thx.

you 'may' have overtightened and stretched the female copper fitting

assuming you are using the 'big box store' cheapo tape:

give 8-10 wraps with NO overlap ( 1/2" tape 'band' on end of male thread) and tighten 1-2 turns past hand tight

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

So what tape should I buy? Always looking to get the right stuff...

[www.homedepot.com]

3 wraps of pink or blue tape or about 6 wraps of the cheap stuff.

..... or, if the female fitting is stretched, 4-6 wraps of the yellow (really thick - rated for gas service) .....

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

bern, you and hj will remember.. wrap the male threads with copious amount of 'wicking' and follow with a few dabs of that grey pipe dope.
a plumber i knew who came from greece told me because their pipe threads were not tapered they used something like horse hair. in fact it may have been horse hair along with something like cosmoline.
[Cosmoline is the genericized trademark for a common class of brown wax-like petroleum-based corrosion inhibitors, typically conforming to United States Military Standard MIL-C-11796C Class 3. They are viscous when freshly applied, have a slight fluorescence, and solidify over time with exposure to air.]
We used to use cosmoline on the boats when i worked at the navy yard. not for pipe dope but for corrosion protection.
i was once involved with 'de-commissioning' a navy destroyer. covered from stem to stern in cosmoline.

Quote

..... They are viscous when freshly applied, have a slight fluorescence, and solidify over time with exposure to air. .....

Sounds like a description of me.





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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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