Re: toning albumen and acidity

[eric nelson <emanphoto@gmail.com>]

Thanks Ryuji,
Well w/my crappy pH paper that I procured, I got a pH of 6 for my
water (how super accurate!), 9-10 for the borax solution only, and a
pH of 8-ish once I added the gold.  The gold solution itself was 1-2.
Even with adding about a gram more of borax under constant mixing with
my magnetic mixer, I still had a yellow solution and the pH went up
slightly it seemed.

Since  the clock was running last night and I had to process the
prints I'd exposed before the fog started to kick in, I went ahead and
processed my prints and they came out OK.  The color of the prints was
not as purplish as I would get with gold chloride I made myself and
have used many times, but it gives a more controlled toning.

I had a little of my home made gold chloride available so I made a
small batch of toner with that, and when it hit the borax solution, it
turned greenish yellow and stayed that way.

I added a little of that to the store-bought gold toner solution
(after toning 2 prints) and after a while I could see a sediment of
some kind forming on the surface in the blacks so I removed the print
and wiped it in the wash by hand.

Aside from the obvious hazards of making gold chloride, it seems to be
a fairly tricky process to get exactly right in that perhaps the
krugerand I had used to make my gold chloride had some other metals in
there as well.
The gold chloride I made shouldn't be too far from the historical gold
chloride photographers would make themselves in the same manner, yet
my home-made batch seemed to be very active compared to the
store-bought gold I have now.
Being used to that higher activity, I assumed something was wrong with
my new batch of store-bought gold.
After successfully completing a titration analysis of my silver
solution, I was feeling pretty confident of my chemistry abilities
only to get frustrated when I didn't have any test for my gold and
only mediocre quality pH paper.
If anyone can suggest a souce for good pH testing paper or strips,
please feel free to pass that along.
Eric








On 9/21/07, Ryuji Suzuki <rs@silvergrain.org> wrote:
> If you mix 10g borax and 0.4g gold chloride and nothing else
> in one liter of water, the pH should be very near 9.
>
> The virtue of borax is that adding more borax doesn't make the
> pH much higher than 9.2. If your toner is too acidic, there
> should be no harm in adding more borax. However, if you bought
> the gold in solution, I'd first suspect (and confirm or
> exclude) that the solution might contain excess acid or
> something.
>
> --
> Ryuji Suzuki
> "People are sick in this country because they are poisoned [...]
> they poison themselves. To my way of thinking why about 90% of people
> are sick is because they eat shit---Bill Maher (2007)"
>