On Mon, 17 Oct 2011 11:02:42 -0500, Jeffrey Angus
wrote:

Isn't that also standard Usenet protocol?

Yes. The first step to analyzing a failure is to blame someone.

Having a vacuum pot and temperature chamber helps make stuff
"right" when you do it. I kind of prefer a polyurethane for
potting myself.

I like to use Bondo, because it doesn't shrink.

Way back in the days when I still received a regular paycheck, the
company had a "modular products" division that sold data converters
into such non-critical applications like missiles and air traffic
control systems. Instead of just dumping the electronics into a
potting shell and filling it with epoxy, they would first fill it
almost to the pour hole with sand and then top it off with epoxy. The
thermal conductivity of epoxy is slightly better than lousy. The sand
gives an even temperature distribution, protects against mechanical
shock, and is cheaper than epoxy. It also makes post-potting repair
somewhat possible. Filling the bobbin with sand before potting isn't
going to do anything useful for your solenoid, but I thought I would
mention it for future applications.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558