I just installed a new sink in my garage using CPVC for the plumbing run. Never used CPVC before. Where I came through the wall, I used a CPVC female threaded fitting with ears on it to fasten to the wall stud. I then screwed a 4" brass nipple to it with teflon tape and attached the valve to the other end with teflon tape as before. I now notice a slight weeping or sweating leak at the CPVC fitting. There is a rubber washer inside the CPVC fitting, so now I'm wondering if I just didn't screw it down tight enough. How tight do I screw the brass nipple into this CPVC fitting? Am I not supposed to use teflon tape since there is a washer inside the fitting? I'm a bit concerned that if I really reef the nipple down tight, it might crack the CPVC fitting itself.
Thanks for your help!

And you should be concerned about cracking the fitting FFF. Good for you.

I would take apart, and pipe dope the brass nipple and re-install using the rubber washer only. Or just wrap teflon 2-3 times clockwise.. ok?

Does your fitting look similar to the fitting in my pic. (except yours has ears)? I think with this fitting you need to feel the threads on the nipple bottom out into the rubber washer... but it is going to be scary... no choice though.. OR could remove the washer and use 7-8 wraps of tefon and re-install that... but still need to tighten pretty good. Hold against yourself with pliers as you tighten the brass nipple in and you should be fine.

Hope that helped... Good luck... Mark

I used a CPVC female threaded fitting with ears on it to fasten to the wall stud. I then screwed a 4" brass nipple to it with teflon tape and attached the valve to the other end with teflon tape as before. I now notice a slight weeping or sweating leak at the CPVC fitting.

Using metallic threaded fittings on plastic female fittings is just asking for trouble, particularly on the hot side of the system.

Expansion and contraction within the system will eventually crack the female fitting.

If you want to make a proper plastic/metallic transition, then you should use an approved brass to CPVC drop ear 90 (http://plumbing.hardwarestore.com/52-333-cpvc-elbows-and-tees/drop-ear-elbow-101533.aspx).

FFF:

Growler's right on... If you can get your drop ear fitting off the studs, I would change over to the fitting he showed you. A better job in the end.. for sure!

Let us know what you decide.

Thanks all!
I figured the risk wasn't worth it, so I opened up the walls and replaced each with the SharkBite brass connectors. Everything works great now and I can sleep nights.
Again thanks for the advice!

Can't beat the sharkbite! Thanks for update. Take care now... Mark