Glyoxal amounts (was: Re: After IKE and paper size
Wow, Marek, this is one of the more upbeat disaster stories I've
ever heard. Thanks for the report, and glad all is well.
And thanks for the research on glyoxal, that's very interesting and
useful. The amount you were using before seems high to me, but
that's neither here nor there; it doesn't undermine your findings at
all. And I'm used to hearing the standard recommendation as a ratio
of 40% glyoxal to total solution (15cc of 40% glyoxal to 1 liter of
3.5% gelatin solution is the way I've usually heard it) rather than
as a ratio of glyoxal solution to dry gelatin. Soooo...what my
routine practice works out to (going straight by the standard
recommendation) is 3cc of 40% glyoxal to 7 g gelatin, which is half
what you were using, but by your findings it's still 10X too much.
This is significant information, thanks.
Look forward to seeing your palettes. A fine use of "down time," I
must say.
Katharine
On Sep 24, 2008, at 6:26 PM, Marek Matusz wrote:
Hi everyone,
I have made it through hurricane IKE and just trying to go back to
normal. It has been an interesting experience, which I mostly
liked. We did not encountered any life threatening situations, and
only some damage to the house and yard. We lived without power for
9 days, no TV, internet and no phone at times. We had water and gas
and plenty of wine and it was like a long camping trip.
I sized a lot of paper and did some controlled experiments with
glyoxal as hardener as it was what I had and wanted to use. I made
a 3.5% gelatin solution and hardened it with increasing amount of
glyoxal. Samples were placed on a glass plate and two days later
soked in warm and then hot water. This way I could really deternie
how much glyoxal is needed to crosslink the gelatin to where it
would swell but not dissolve. It went throgh patches that dissoled
easily to those hard as a rock, so I know I covered the
concentrations needed.
In my experiments I determined that a solution of 2 packets of
gelatin (14 grams), 400 cc of water needs 6 cc of 4% glyoxal. That
is correct. I diluted gyloxal 1:10 and used 6 cc of this dilute
solution. My old method was 12 cc of 40% glyoxal for 14 grams of
gelatin. I am hoping that much lower concentration of hardener will
eliminate some of the yellowing associated with glyoxal (not that
it mattered to me that much as I soak next day after size to shrink
paper and water soak always eliminated yellowing).
I was quite surprized that I used way to much glyoxal. Way too much
that is actually needed to crossling gelatin. The ratio that I used
came from the discussion on the list a few years back.
ANyways it was a good experiment and I had plenty of time on hand.
I also printed in the last two days to make up for "lost" time. I
will actually try to post some my tricolor work demonstarting
different palletes later tonight.
Happy to see that the list was quite busy.
Marek
Stay up to date on your PC, the Web, and your mobile phone with
Windows Live. See Now