[Top=-posting corrected]
RST Engineering wrote:
the gaskets out to near the open end of the shaft, heat them red,
then slide them off the end and they fall into the water.

Oh, please, for the love of God, don't do this. This is how you
HARDEN them, not soften them for the annealing process. Heat them
red hot with a torch and let them cool in ambient air to soften them.

Well, I guess this depends upon if your gaskets are made of copper or of
iron/steal.
Although, I've never seen gaskets made of iron but of course nothing is
impossible.

jue