V. Potting Dissolving Chemicals:

1. Dynaloy Inc.,1910 S. State Avenue, Indianapolis, IN 46203 Phone:
800-669-5709 Fax:
800-671-9583

In article , beerbarrel
writes:

any way to remove the gel like compound in some electronic components?
I have a ps that I would like to rob parts from but its frozen in a
block of clear gel like material. There has to be an easy way to
remove this substance? Any ideas?

If it is relatively clear and rubbery with a slight "give" to it, a guess
is that it is probably a low out-gassing silicone potting compound
such as used in some spacecraft electronics. Those were all
one-time pottings, done after checkout and never intended to be
un-potted for any reason.

My advice is to NOT use any solvents of any kind for the simple
reason that such can get into some of the internal components
and do nasty things. Solvents have very low (almost negative)
surface tension and could penetrate any component not
hermetically sealed by metal-glass cases or all-ceramic, fired
cases. Those potting compounds of various epoxies or silicone
types were near-vacuum debubbled just before mixing their two
parts (also in the same near-vacuum) and would surround the
components but not penetrate their cases. Note: Some of those
potting materials were transparent or translucent like the common
silicone conformal coating used on old PC Boards for spacecraft.
That kind of potting material polymerized once and once "set"
was NOT usually dissolved by ANY solvents.

You MIGHT be able to use a soldering iron to dig into the potting
material to loosen most of it, but that creates some (unknown
effect) smelly vapors. In the end, the parts would have to be
salvaged by mechanical means such as carefully picking away
the stuff by a model knife (old reliable X-Acto type and its
cousins with lots of spare blades for replacement). That's a
very labor-intensive task...like two working days to remove the
translucent potting compound around a multi-stage voltage
multiplier block for the designer's evaluation after full environment
testing (EOS Spacecraft Fab Lab back in the 1960s). It may not
be worth it for a hobbyist. That's an individual call.

Jet Propulsion Laboratory in Pasadena, CA, had, and presumably
still has an excellent polymer laboratory and "rules" for NASA on
polymers for spacecraft. Somebody there could give better
advice (information is free, unclassified, but speaks in chemistry
terms, not requested much) on potting removal methods. That
isn't "casting plastic" (acrylic) one can buy at the Michael's craft
store chain.

Emerson and Cuming are specialists on potting and coating
compounds for electronics (also wideband RF absorber material).
You might inquire to them about this material and see what they
have to say. Also anyone that makes silicone rubber compounds
for potting or just do a search for "silicone potting" (not just the
word "potting" or there are too many hits on the results).