Topband: Beverage transformer enclosures

Bill Wichers billw at
Fri Nov 11 08:18:37 PST 2011

Have you tried sealing the innards with a potting compound? Repair and
modifications become pretty much impossible after doing that, but it
does tend to keep the moisture out.

Myself, I use small ABS enclosures that have a sort of O-ring seal in a
grove around the edge. I've been getting them from Fair Radio Sales but
there are lots of other sources as they're a standard type of enclosure.

I also spray the electronics with a conformal coating made by Tech
Spray. I use their silicone-based coating since it's supposed to handle
high humidity the best, but I've had some issues with moisture getting
through anyway. I have been skipping the step of using their "blue
shower" cleaner before using the conformal coating, so it's possible
that my shortcut is resulting in poor adhesion of the coating to the
board. I usually get about 3-5 years before I have to work on faulty
outdoor parts after using the conformal coating in this way.


> Here on Guam, we get more than 90 inches of rain annually.  I have
> that it is impossible to keep water out of enclosures, and if drain
> holes are drilled into the bottom, ants and other jungle critters will
> move in with dirt, ETC, that cause the same problems as a flooded box.

More information about the Topband mailing list