[Prev][Next][Index][Thread]

RE: drying coil forms



I found a cardboard box slightly longer than the secondary.  Next, I
inverted it and put the open end on the concrete floor of the garage.  I
hung the secondary from the new top of the box (ie, the old bottom) , placed
a small hotplate in one corner, and stabbed a cooking thermometer in an
opposite top corner.

I watched the temp rise and cut small holes in the top of the box until it
leveled out at about 180F.  I let it simmer while I worked on other parts in
the garage for 3 or 4 hours.  Nothing caught on fire and the PVC didn't seem
to distort or anything.  I did use some AL foil to make some baffles to
prevent spot heating of the PVC from IR.

I'm a novice at this, but I'm convinced that drying a PVC secondary won't
buy you any perceptible performance gains.  I work in a Space Simulation Lab
for Boeing and wound up discussing my Tesla Coil with some of the satellite
guys at work a while back.  One of the guys happened to be an expert on the
molecular diffusion of water into things that need to stay dry.  He told me
that the only hope of keeping the PVC dry would be regular (monthly)
reheatings.  He says that nothing we can easily buy at Home Depot will
prevent the molecular diffusion of water back into the PVC.

I would love to see some data that demonstrates the performance benefits of
"dry" PVC over "wet" PVC, or even some performance data of the same
secondary coil wound on various formers.

Making arcs in Huntington Beach, CA
Ross Overstreet