I agree that BOTH pipe dope and tape would seem to be overkill, but in
stubborn cases, it works just fine. Check your auto parts store for
"Permatx" pipe/thread dope. Two versions -- permanent and non-so-
permanent. I keep the 2nd around for such cases. The other stuff sets
up pretty hard, and is very difficult to get apart again. The
Permatex products seem to work much better than the usual gray pipe
dope. Get a bigger hammer....