Model Forum / General / Models / December 2006

Ordinary polyester resin used for fiberglass can be pigmented -
special powders are available but I've had good results using
cellulose paint mixed in just before the catalyst. I use beeswax
furniture polish as a release agent, but again special stuff made for
the job is available. Mould material can be almost anything so long as
it doesn't react with the resin - for that size I would probably use
plywood as a mould, giving it a few coats of car spray paint and
rubbing down between. There are special filler powders that can be
added to the resin to make it more robust and chip resistant if that
is a potential problem.

AWEM

You can buy battery boxes off the shelf in Maplin

    --Sounds like a lot of trouble. Howzabout bending it up out of
aluminum, then if you want line it with duct tape.

Look for "potting resin" or "encapsulation resin" at your prefered
electronics supplier, RS, Farnell, Maplin etc. It's usually black and
contains filler so is not brittle, it will stick to most things but
roughning the surfaces will help.

You can also get "potting boxes" designed for the purpose, spray them
with furniture polish, back-to-black etc and they should release if
that's what you need.
Greg

Just a thought,
have you considered that batteries can get hot when discharged / charged &
might also want to vent gasses ? worth considering otherwise you might get a
split bit of carefully made potted part, or a nasty bang ! I'd be tempted to
pot batteries in silicone RTV sealant in a maplins or whatever type box,
that should allow some allowance for expansion.
Mark G.