Re: Help with what I believe is a hardening issue

On Tue, 9 Nov 2004, ericawd wrote:

> I am mainly a lurker/gum printer who has learned a great deal from the list.
> I could use some advice.
>
> I am having the same problem described below by Judy Seigel. I have come to
> the conclusion that the problem is the fact that the formaldehyde I am using
> is approximately 3-5 years old and is no longer hardening. I have tried
> every avenue I could think of to replace it locally in Memphis, Tennessee to
> absolutely no avail. I used to buy it at a drug store, but one now needs a
> prescription in order to purchase it.

Candace,

Formaldehyde is a preservative; it does not go bad. I've kept the same
bottle for 10 years, or longer, in fact until the contents dried into a
white powder at the bottom of the bottle. Sarah Van Keuren proudly
declares she's worked out of the same muddy old tub of working solution
formaldehyde since genesis (practically).

Plus, when gelatin isn't hardened at all, it doesn't do that speckling you
describe... it simply stains in the whites. Therefore I suggest that
something else is going wrong...

Here are other causes I've found over the years for speckling:

Making the gelatin too weak... When I began teaching gum I had the formula
wrong: It's 28 grams per litre. For some reason I'd been using about half
that... and after a week of testing, discovered the error.

Another case of speckling was created by a student who was developing his
prints in scalding water.

Something that looks mighty like speckling can occur if you slap the sheet
of paper with wet gelatin on it into another, so that the gelatin pulls,
or forms bubbles.

Speckling can also occur if your gelatin has spoiled, which it can do in
as little as a day when left out at room temperature. I'd also check the
pattern of the speckling -- if it's image-specific, it's probably
something in the emulsion. (Have you changed gums or some other
ingredient lately?) If it's just free floating, especially in non-image
areas, then odds are it's the size.

But again,formaldehyde preserves corpses forever -- it doesn't spoil...
unless of course it was contaminated to begin with ?!

PS. the last formaldehyde I bought I got from the drug store by
prescription. Do you have a family doctor? A nice one might well oblige.
Also, TALAS had it in their catalog years ago. Might still.

Judy
Received on Wed Nov 10 00:29:15 2004