Homebrew PCBs

Steve Greenfield wrote:

> "Stefan Trethan" wrote:
> > ... simply mix solid chunks of colophony resin with  
> > methylated spirits (ethanol alcohol) ... 
> 
> For those of us in the US, I believe you mean what would 
> be called "denatured alcohol" here. It is primarily ethanol 
> (grain alcohol, therefore drinkable by itself) mixed with 
> methanol to make it toxic.

I haven't seen any (genuine) "denatured alcohol" that made use of
methanol in a long, long time ... simply because the mixture _IS_
toxic.  What gets used now is denatonium benzoate, the same stuff 
used in anti-nail biting polish for kids. While it's not toxic, I
understand no human can stand its taste, and if any actually gets
ingested, nausea results. It also includes methyl isobutyl ketone
and acetone (dimethyl ketone), which are also toxic but not brain
damaging like methanol.

In the U.K., however, denatured alcohol formulations do include 
methanol (and a few other nasty things if I remember correctly).

Isopropyl alcohol is quite a different thing, but which is most
usually found on drugstore shelves labeled as "rubbing alcohol"
or just "alcohol." It doesn't need to be denatured since nobody
wants to drink it in the first place.

I don't know if any of this makes any difference but it wouldn't
be the first time if it did.  I assume colophony resin dissolves
in any sort of alcohol, regardless of the presence or absence of
methanol.  But, if colophony resin _won't_ dissolve in isopropyl 
alcohol, then an effort will be needed to find genuine denatured
ethanol. And, if that's hard to find (as it is here), then I say
just use Vodka (unless, for some odd reason, the colophony resin
actually does require at least a little bit of methanol, say 10%
or so).

--
WB