[Elecraft] KSYN3A mod problem

[David Woolley]

PCBs (FR-4) are glass reinforced epoxy, not polyester (I think the old, 
brown ones (SRBP) are paper reinforced urea-formaldehyde).  Also the 
resin component is cross-linked, whereas the article is talking about 
thinning the uncured (un-crosslinked) resin. (Glass reinforced polyester 
is used in car body repairs because it is cheaper than epoxy.)

I'm not saying that acetone is a good thing to use on electronics, only 
that the rationale in relation to PCBs is flawed.

Incidentally, methanol, an alcohol, softens, but doesn't dissolve, cured 
epoxy.

-- 
David Woolley
Owner/builder K2 06123

On 08/09/15 00:02, Fred Townsend wrote:

>>From Wikipedia:
> Acetone is a good solvent for many plastics and some synthetic fibers. It is
> used for thinning polyester resin, cleaning tools used with it, and
> dissolving two-part epoxies and superglue before they harden. It is used as
> one of the volatile components of some paints and varnishes.
>
> Polyester resin, also called gel coat, in case you don't know, is the stuff
> PC boards are made of. Leave acetone in the paint department where it
> belongs. I suggest alcohol, any kind as long as it pure, be used for
> de-fluxing PC boards.