On Tuesday, Dec 2, 2003, at 14:02 US/Pacific, John J. McDonough wrote:

> If you don't have any silica gel saved from something, another
> approach is to pour in some calcium chloride like you use to melt snow.
> CaCl2 really scarfs up the moisture, tho, and it's pretty corrosive,
> so I'd
> arrange something to keep it, and your board, apart.  Also, you will
> want to
> cook it initially as it will probably be totally saturated when you
> get it.
>
nope.  Saturated CaCl2 is a liquid.  If it's still solid, it's not
saturated.

Silica gel is easily purchasable these days.  One cheap form is a new
style of
kitty-litter.  (Come to think of it, the desicant usually packed with
SMT chips
doesn't seem to be much more than REGULAR kitty-litter (bentonite clay.)

Epson salts and plaster of paris are also usable desicants (if heated
and
dehydrated first.)

I'm pretty sure than any solvent that will dissolve silicone will do
nasty things to
the "lesser polymers" that seal caps, insulate wires, and so on...

I've heard that candle wax (ie USA style "parrafin") makes a reasonable
encapsulant.
Easy to find, safe to use, easy to get off (by melting.)

BillW

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads