Homebrew PCBs

I've used both and I'll tell you that 30% water makes a big 
difference in the amount of residue left behind.  Many printers 
specify using 98+% IPA and will specifically caution against using 
drug store IPA.  Now I only use 70% IPA for removing sticker residue 
from EPROMs.

Try some of the good stuff and you'll see for yourself.

I buy 98+% IPA at Frys Electronics and hospital pharmacies for about 
$4/pint.

Anhydrous IPA is hygroscopic, so it will absorb water from the air.  
But not nearly as fast as the poster implies.  I put an ounce or two 
in a pump-up dispenser and it's air tight enough for it to keep for 
weeks.  Just don't buy it in gallon containers unless you have a 
vacuum pump to remove air before you close it.  You could probably 
use one of the gadgets they use to pump air out of wine bottles 
after they've been opened.  Any specialty wine store should have 
them...

Regards,
Dennis
--- In Homebrew_PCBs@yahoogroups.com, lists 
<stuart.winsor.lists@...> wrote:
>
> In article <dt7q8s+6hv3@...>,
>    kilocycles <kilocycles@...> wrote:
> 
> > In the 2006 Allied catalog, there is some very desirable stuff:
> > 99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz 
(100 ml)
> > at $4.46, but not bad for 500 ml at $6.53.  So, it's available.
> 
> Hmmm, and the moment you open the bottle it will start absorbing 
water
> from the air - stop worrying about it. Ordinary IPA is perfectly OK
>