Sealant for NPT fittings

[JCTyler]

I'm still working on my Alfa A/C rebuild and am considering using pipe dope as a thread sealant. I've also seen good reviews of this. Viper Nylog and thread sealant. What's your preference? Pros and cons of both?

[JohnHere]

Here's what I said in another Forum on this board in case you missed it.

I wouldn't use any kind of plumbing pipe dope for NPT or NPS fittings because of the risk of contaminating the system with incompatible substances.

I wouldn't use plastic tape on the threads, either, because any remnants of the tape that inadvertently find their way into the system could clog critical components.

Nylog Blue is the only sealant I know of that will do the job and that is compatible with MVAC systems.

[Tim]

Agree with John, Nylog for threads and o-rings.