Does anyone know of a source for BRONZE tapered thread [pipe thread]
thru-hulls?

The thru-hulls sold by Worst Marine and others are all "straight
thread" with straight thread tightening nuts. The sea-cocks that go
on these thru-hulls are also straigh threaded, but are designed to be
bolted [ usually 3 bolts ] through the hull also. It would seem that
for a fiberglass hull the less holes the better.

So many people put a tapered thread ball valve [seems like all ball
valves are tapered threaded] on to the straight thread thru-hull. Not
a good idea.

T. Sanders
S/V Cimba