I use PVC-E on upside down Ampico/Amphion unit valves because of the
large gap and expanding and contracting cardboard spacers (very rarely
on other valve caps).  I seemed to be advocating using PVC-E on all
valve caps, but that's not my intention.

It would be a bad idea (in my view) to seal most valve caps with PVC-E
because it would make the valves less serviceable than sealing with
shellac would.  Oops!  Sorry!

Bill Maguire

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