Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Blair, William"
<William_Blair@b...> wrote:
>
> 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.

There are quite a few materials authorized for denaturing ethyl 
alcohol.  The exact formulas may be found in the US government
regulations 27 CFR Part 21:

http://www.access.gpo.gov/nara/cfr/waisidx_05/27cfr21_05.html

> 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

Dave