From: Judy Seigel (jseigel@panix.com)
Date: 12/05/01-07:28:40 PM Z
On Wed, 5 Dec 2001, Sandy King wrote:
>
> I don't know what the latest word is either but I have definitely
> experienced paper yellowing with glyoxal. That, plus the news that it
> apparently goes bad with age, which I had not heard before, drops it
> pretty low on my list of hardeners, even though I have a couple of
> pints of the stuff on hand!
>
> For a fact I know that Formaldehyde does not yellow paper and lasts a
> long time. Over 15 years ago I bought a gallon of the stuff and still
> have a lot of it left and it seems to work as well today as the day I
> bought it. However, Formaldehyde is real nasty stuff to work with
> inside. Even with good ventilation the odors can be very pungent and
> you definitely do not want to be breathing them.
Let me clear up some confusion -- Any yellowing from glyoxal is when the
hardened paper sits for months before use... It soaks out with a long
soak, and/or clears up with clearing bath. I myself have seen it on the
paper on a few occasions -- but NEVER in a finished print.
However, I'll add that I have worked a LOT with formaldehyde and even have
an unopened bottle of it on the shelf, and will NEVER if I can possibly
help it use it again, unless I need to pickle someone.
On my initial tests of the glyoxal vs the formaldehyde, I hardened both
OUTDOORS and left a FULL DAY to dry in the air on a nice cool breezy
summer day, then brought the two batches inside. The outgassing from the
formaldehyded paper was so strong ONE DAY LATER I had to take it out of
the studio & had burning throat and eyes for hours. Maybe I'm more
sensitive than other people, but I would not willingly use the stuff
again, even OUTDOORS.
In winter it isn't feasible to do it outdoors -- not up here in Northern
Morton Street. And sometimes in winter I really really want paper.
One year I was desperate & did it in our front hall, opening doors front
and back to create a cross draft, and setting up two fans. (Some of us do
NOT have a barn or garage !) Not only was the gas so awful throughout the
house it could have killed the tenants fish on the top floor, we nearly
froze to death.
What I do now is mix only the glyoxal I'm going to use that day, also add
20% methanol to working solution. It keeps about 24 hours -- and the 40%
stock solution in the bottle from Artcraft keeps indefinitely.
It's possible it would keep a bit better in the refrigerator (Ted????),
but it's not necessary if I'm organized, and sometimes I am. And I don't
care what the MDS says, I can hang the glyoxaled paper to dry in the house
(& have done so for a class) with no perceptible odor. Formaldehyde MUST
be dried outdoors, or you're soon on the floor grasping your throat and
crying for the EMS.
> On the whole I find chrome alum less obnoxious to work with than
> formaldehyde, and it appears to harden the gelatin just as well
> without any of the yellowing of glyhoxal.
That's on my list of things to try (tho list is longer than I am)... you
put it in the gelatin or a separate bath??? For several reasons I prefer
two separate baths -- better control, etc., but.... I guess it would have
to be tested both ways... And I've already tested the gylyoxal. ;)
PS for those not around when I made the initial report on the two
hardeners-- the glyoxal-hardened gelatin stained noticeably less than the
formaldehyde hardened paper... Or did when I tested about two days later.
Maybe it hadn't fully outgassed. So strictly speaking that should be
repeated say, two weeks later.
But not by me,
best,
Judy
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