Re: Chrome Alum Gelatin hardener

Clay,

The 2g per liter of chrome alum I recommend is correct. But don't add
the chrome alum directly to the warm gelatin solution. Rather,
dissolve it first in about 150ml of warm water and then add.

Waiting five days is on the very conservative side. I would imagine
that in your application drying over-night will give sufficient
hardening.

Sandy

>This question may be directed more at Sandy, if you are listening. I am in
>full-blown psuedo-panic mode preparing my gumover portfolio for Fotofest, and
>am thinking that my usual method of using glyoxal as my gelatin sizing
>hardener is a little limiting for my new assembly line approach to printing,
>since I have to hit the prints with gum fairly soon after the sizing step. The
>glyoxal works fine when I do a handful of prints at a time and know that I am
>going to get to them in a few days, but they always represent a ticking time-
>bomb after I size the prints.
>
>I did a web search and saw that you are using chrome alum as a non-yellowing
>gelatin hardening agent for your carbon paper support. Since I have some of
>that on hand, and I am having some problems getting formalin, I think that may
>the best hardening agent to use.
>
> In your carbon book, you recommend 2g of chrome alum/1000ml of gelatin
>solution. This seems like a very tiny amount. Is that about the right
>proportion to get a 'medium' hard gelatin coat? And you recommend waiting
>about 5 days for the hardening to fully occur. Is that still your experience?
>
>Thanks,
>
>clay
Received on Sun Feb 8 10:47:24 2004