Re: glyoxal yellowing now: How do you know it's hard?

From: Christina Z. Anderson ^lt;zphoto@bellsouth.net>
Date: 02/04/05-09:10:57 AM Z
Message-id: <003f01c50acb$bcca4aa0$6101a8c0@your6bvpxyztoq>

Clay,
I'll refrain from any jokes about your subject line, heheheh

I figured out the math on Maco glut from Kees' post. IF you use the 5% as
they say it is (tops), mix that with 100ml water, use 20-50ml of this stuff
in 1000 ml gelatin, that is ** .0125% **of glut tops in your mix. That's if
you use the top figures for Maco's recipe as reported in Kees' post here (if
I am reading his punctuation correctly and 2-5% means a range and not 2.5%):
http://www.usask.ca/lists/alt-photo-process/2004/feb04/0527.htm

My dilution with 6ml 2.5% in a liter of 2.8% Knox gelatin is ** .015%
**glut, so slightly higher.

I have not tried higher; I have tried half that but prefer the higher.

Now, as far as availability; Ryuji sent me my sample so I was lucky, because
I did not know where you could get any. Now that Kees has posted about
Maco, and posted the recipe, I realize we have sources for the stuff in the
photographic world. In fact, the Photographer's Formulary sells a hardener
under the PF label that sounds from Kees' recipe that it might be repackaged
Maco. I had used it way back when with their proprietary liquid emulsion
(more than likely a repackaged Silverprint or Maco product). I could not
BELIEVE the recipe on the label was so minute (diluting the hardener and
then using miniscule amounts). Now that I think it is glut, my conclusion
unscientific as it may be is that a little goes a hugely long way.

I ran a "chrissie" test (as opposed to scientific) and left my remainder of
my gluted gelatin outside in a cup for days. It never turned rock hard. It
did gel. I was able to reliquify it to a certain extent. Whatever this
means, who knows, but in all the sizing I have done with glut it is smooth
and predictable and soaks in well unless you size at night in the dark and
cold and then of course the gelatin decides to be jello and leaves streaks
with brushing.

My question is this: with all the dire warnings about glut, if it is
already packaged for us in the photographic community as Kees has pointed
out, maybe the dilution is low enough that exposure to it is a minimal risk
and not a maximal like a 40% glyoxal might be, or a 37% formaldehyde. I
can't answer that, not being a scientist. But Kees' post and repost about
the Maco glut has me one happy woman. Maybe more of us can put it to the
test.
Chris

> The whole gelatin hardening debate makes me wonder if there is any real
> easy
> way to tell if it(the gelatin) is hardened enough. Is it an on/off thing,
> where it is either hardened or not, or are there degrees of hardness? My
> question is asked because the amount of hardening agent should ideally be
> just the minimum needed to cause the gelatin to harden enough to keep
> highlights nice and clean.
>
> On another note, can someone point me toward a source for glut? I seem to
> recall this being mentioned on the list about 6 or so months ago, but I
> can't find it, and I'm feeling lazy.
> Thanks,
> Clay
Received on Fri Feb 4 09:11:43 2005

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