Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Len Warner <yahoo@...> wrote:
>
> On Wed, 26 Apr 2006 at 00:33, Steve wrote:
> >    Date: Wed, 26 Apr 2006 00:33:49 -0000
> >    From: "Steve" <alienrelics@...>
> >Subject: Re: cleaning solution for inkjets - Steve
> >
> >Wow... according to the MSDS, this one is only 1 to 5% ammonia, if I'm
> >interpreting this correctly:
> >http://www.mchem.com/test/Pacific%20Ammonia.pdf
> 
> Thanks for the link, Steve, I know _exactly_ what you are using.
> I'm off to the supermarket this afternoon to check what our
> common UK formulations are (Windolene, Goddards, and so on.)

Did you see the other info I forwarded about Windex with Ammonia
equivalents outside North America?

> >So you'd better water it down a lot more than that!
> 
> And you also ought to check that the concentration is
> expressed in the same way: Ammonia in water is
> sometimes quoted as NH3 and sometimes as NH4OH,
> roughly a two times difference in numbers. It may not
> make much difference as an ink cleaner, but it will get
> up your nose less to use it weaker rather than stronger.

I was concerned about the method of measuring concentration.

I can attest that stronger concentrations do not clean any better,
however they will gas you! With the concentration I'm using, it takes
only moderate ventilation. I started out with much higher
concentration and even with a window open with a fan on high 4 feet
from me, I had to leave the room after a few minutes.

BTW, I have been told that the basic pH of the ammonia solution is a
critical part of how it works to break down dried ink. This fits with
using FeCl (an acid) to etch. So I would make a guess that pH of the
etchant matters quite a lot. I have FeCl, and of course I can get the
ingredients to make CuCl.

Steve Greenfield