U of S | Mailing List Archive | alt-photo-process-l | Glyoxal amounts (was: Re: After IKE and paper size

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.


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.

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