Re: report on glyoxal yellowing

Dear Christina,
I have some fabriano paper and lanaquarelle paper that
I coated six weeks ago that shows no yellow stains. I
didn't even rinsed the glyoxal from the paper.
I will keep my eyes open and will report if any yellow
appears!
Carmen

--- "Christina Z. Anderson" <zphoto@bellsouth.net>
wrote:

> Carmen and Candace,
> I apologize for replying to two emails at once,
> but:
> Carmen, the yellowing does not occur right away, but
> after, let's say,
> several weeks or more, or even less. Clay Harmon
> noticed his in a week.
>
> Candace, I went back over the archives to see what
> other papers yellowed,
> and unfortunately I couldn't see any paper names
> mentioned. I know Clay and
> Kerik both experienced yellowing. So did Kees
> Brandenburg.
>
> There is disagreement whether, once the yellowing
> occurs, it is removable
> with a soak. Judy says yes. Kerik says no. I think
> my answer is no, but
> I'll soak my measely little strips and tell you.
>
> I attach a message at the end from Kees about this
> from a couple years ago.
> Otherwise,
> you can search for "glyoxal and yellowing" in the
> list archives from about
> 1999 onwards.
>
> For those of you long term listies (I've only been
> on since 99), who
> instituted the use of glyoxal for hardening in alt
> process? Luis Nadeau
> says this below. Dick Sullivan, do you know? I've
> cut and pasted this.
>
> " Luis Nadeau (nadeaul@nbnet.nb.ca)
> Tue, 19 Jan 1999 16:25:56 -0400
>
> I'm curious, does anyone know the long term effects
> of glyoxal on paper?
>
>
> It's been used for decades in the photographic
> industry. I first read about
> it when studying Pierre Glafkidès' _Chimie et
> physique photographique_ in
> 1976. The previous edition may have had it as well.
> The effect should be
> the same as formaldehyde.
>
>
> Luis Nadeau
> Fredericton, NB, Canada "
>
>
> And "Kees said, "These are my observations with
> glyoxal and yellowing:
>
>
> I coat my paper for gum in a 3 % gelatin solution by
> immersion in a tray.
> After drying (at least one night) I soak the paper
> in 1 liter of
> water containing 25 ml of a 40% glyoxal solution
> with some borax
> added. In fact I am copying exactly as I was doing
> with formalin.
>
>
> After 2-3 minutes in the bath I put the sheets in a
> tray with running
> water and leave them in for some minutes.
>
>
> After drying there is no apparent yellowing.
> But....when these papers
> are kept (in the dark) for some weeks an significant
> yellowing is
> visible alover but most apparent at the edge where
> the gelatin is a
> litlle thicker.
>
>
> The yellowing was more severe when I started using
> glyoxal. At that
> time I did not rinse the paper afterwards as I do
> now.
>
>
> I think there is indeed a relation between
> concentration and yellowing.
>
>
>
>
> glutaraldehyde
>
>
> Apart from this I looked at glutaraldehyde too and
> found in the
> archives that MACO hardener (LP-Geladur and MACO LPE
> 510 hardening
> additive for Black Magic emulsion) contains
> glutaraldehyde too.
>
> As I have a bottle of LP-Geladur here,I asked MACO
> for the exact
> proportions and they kindly did send me a recent
> (Feb.9 2004) safety
> sheet. It says:
>
>
> disodium disulphite 5-10 %
> glutaraldehyde 2-5 %
> acetic acid 0,5-2 %
>
> Apart from these figures being not too exact (but
> good enough for
> safetysheets I presume) one can see indeed that the
> glutaraldehyde
> concentration is rather low. Especially when knowing
> that the
> solution is a concentrate to be diluted before
> adding (to the liquid
> emulsion). For hardening their photogelatin they
> advise a working
> solution of 5 ml concentrate on a total of 100 ml
> water. From this
> dilution one should add 20-50 ml per liter gelatin
> solution. What I would
> like to know (I will try if it works myself too of
> course) what the acid and the bisulphe are doing in
> the hardening
> process. Disulphite is often advised to neutralise
> glutaraldehyde
> before disposal. And I was thinking that an acid
> environment
> prevented an effective hardening by aldehydes." Kees
> Brandenburg
>
>
> ----- Original Message -----
> From: "Carmen Lizardo" <carmenlizardo@yahoo.com>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Saturday, November 13, 2004 2:59 PM
> Subject: Re: report on glyoxal yellowing
>
>
> > Dear List,
> > Yesterday sized Fabriano Artistico and
> LanaAquarelle
> > hot press paper, using knox gelating and hardened
> > using 15ml of Glyoxal, 1/2 tsp of baking soda per
> > liter of tap water. I found no yellow stains.
> >
> > Carmen
> >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > Check out the new Yahoo! Front Page.
> > www.yahoo.com
> >
> >
> >
>
>
>

                
__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
 
Received on Mon Nov 15 11:04:19 2004