Re: Using Gluteraldahyde; was: Glutaraldahyde activation?

Don,
Thanks for the report. I'm curious why you decided to use a different
percentage from what Chris uses. (If my numbers are right, yours comes
out to .0225% of the total gelatin solution, or 1.5 X what Chris uses).

I still rather suspect that my lousy results with glutaraldehyde as a
size were because I used too much (.04%, or 2.7X Chris's), but I also
used different papers (my glutaraldehyde experiments were on Lana and
Fabriano Uno papers) so it's impossible to draw any inferences from the
difference between my results and yours and Chris's. It will be
interesting to see your results on BFK.

Also, I haven't used the Fabriano Artistico Extra-White all that much,
as I don't like the open surface texture, but in the few tests I have
run with glyoxal on that paper, I have got mixed results, whereas I get
consistently beautiful results with glyoxal on Arches Bright White. So
I'm inclined to agree with Chris that it's not just the hardener that's
crucial, but the combination of hardener and paper, which as has been
pointed out may well turn out to be different for different people under
different conditions. Judy was suggesting that maybe it's something as
basic as the water in different places; I suppose that's possible, but I
also wonder if the different dichromate dilutions we use may be a factor
in why the same paper-hardener combination works well for some people
and not others.
Katharine

Don Bryant wrote:
>
> Keith and Ryuji,
>
> Since Keith brought up the subject of gluteraldahyde (hereinafter "glut") I
> thought that I would mention that I have finally had a change to use it to
> harden gelatin for gum printing.
>
> The results for me have been nothing short of excellent. No staining or
> speckling occurred. NONE! The gum coats are smooth and there is absolutely
> no grittiness in the exposed and unexposed coatings.
>
> I'm using the 2.5% dilution with pH of 3.5, kindly prepared for me by Ryuji.
> I've only had time to use the glut hardened sizing on Fabriano Artistico
> Extra White HP as soon as time permits I will test other papers, Rives BFK
> being the first.
>
> Just for the record I was very cautious handling glut. I only used .9ml to
> mix in with 100 ml of 2.8% mix of gelatin.
>
> I used about 2.5 ml of the glut/gelatin mix for an 8x10 size piece of paper
> (pre-shrunk) and rod coated the sizing. I simply made to passes across the
> paper surface and pushed the excess onto a sheet of news print that lay
> beneath the FAEW. Coated sheets were then hung to dry.
>
> I wore a respirator, one made to absorb fumes from paint, not the specialty
> respirator that Kerik uses for formaldehyde. I also had good ventilation in
> my coating area and also wore eye protection. I did not sense any sensations
> or ill effects from the glut. I did make sure that the beaker of gelatin and
> glut remained covered.
>
> I would like to use less of the glut by hardening smaller volumes of gelatin
> at a time. Kerik mentioned that he adds six drops of formaldehyde to 10 ml
> of gelatin. I'm curious to know how he mixes the two uniformly.
>
> Thanks to Ryuji and Chris for working with me and encouraging me to use
> glut. I'm sorry I waited so long. The prints I made this past week were the
> first prints I've made in a long time where I "felt" the magic of print
> making.
>
> Don Bryant
Received on Fri Sep 30 07:01:06 2005