Re: sealants


Regarding sealants.  When I built my 6.0" dia secondary, I had the luxury of
using my brother in laws lathe.  We mounted the core on the lathe using round
wooden plugs in each end.  Then I brushed on about 6 coats of oil based
polyurethane.  We used heat lamps and let it dry about 30 minutes between
coats.  After we wound the wire on, which only took about 35 minutes, we
coated the finished coil with another 6 coats.  It worked quite well, dried
to a nice finish and doesn't seem brittle at all.  The only problem I had was
with small air bubbles that would rise up between wire turns as the
polyurethane dried.  We finally concluded this was due to too much heat from
the heat lamps.

Ed Sonderman