Re: Glyoxal?

Hi Dave et all,

one thing (amoung many) that I don't understand, I found a paper on gelatin
where I read that both formalin and glut are use to harden gel capsule
amoung other things. We eat this stuff all the time and yet manipulating it
is harzardous. From what I can figure out, when either hardener are use such
that all of it get cross linked it would seem that from then on it is no
longer a healt hazard. If this interpretation is correct, would this mean
that all we need to do is to find the proper concentration needed to cross
link the gelatin properly for our purpose and with proper care and safety,
after that we should be ok???

I read in this paper that we can cook gelatine at around 500 F and this
causes polymerisation could this be useful???

I have a few more question on this, one is about the color, I'd like to know
amoung the various hardener we can use which (if any) would be colorless???

What about permanance, is there one of these that is more "permanent" then
the others???

Are there some process that are sensitive to sizing in terms of quantity
(thickness) RH and PH???

Thanks
Yves

----- Original Message -----
From: "Dave Rose" <cactuscowboy@bresnan.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, January 16, 2006 8:58 AM
Subject: Re: Glyoxal?

> No. I would never use formalin indoors, even in very small amounts. As
> long as it's above freezing and the wind isn't blowing too hard, plan to
> harden your paper outside.
>
> Dave in Wyoming
>
> ----- Original Message -----
> From: "Loris Medici" <loris.medici@altinyildiz.com.tr>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Monday, January 16, 2006 4:59 AM
> Subject: RE: Glyoxal?
>
>
> > Hi all,
> >
> > I presume "took it outside" suggestion is when you harden in trays. I
> > assume it would be safe to use formalin indoors when using a very small
> > amnt. - such as brush sizing. (Think of 100ml %3 gelatin solution +
> > 1.5ml formalin) Am I correct here?
> >
> > TIA,
> > Loris.
> >
> > -----Original Message-----
> > From: Judy Seigel [mailto:jseigel@panix.com]
> > Sent: 14 Ocak 2006 Cumartesi 05:32
> > To: alt-photo-process-l@sask.usask.ca
> > Subject: Re: Glyoxal?
> >
> >
> >
> >
> > On Fri, 13 Jan 2006, Christina Z. Anderson wrote:
> >
> > > Personally, if I wasn't using glut I would go to formalin before
> > > glyoxal.
> > > It's worked for centuries--well, 1 1/2 centuries.
> >
> >
> > Where do you get formalin, Chris? In NYC you need a doctor's
> > prescription, or maybe a mortician in the family. I can get the former,
> >
> > if not the latter, but don't because I find it so painful to use indoors
> > &
> > don't like outdoors in winter. Plus, as I've said probably too many
> > times, glyoxal cleared better (for me, anyway).
> >
> >
> > J.
> >
>
Received on Mon Jan 16 08:18:10 2006