Is there a Chemist in the house?

[Photo Engineer]

I'll never use glyoxol again. Works fine if it is very fresh, but as the bottle ages, it causes the gelatin to yellow unacceptably, regardless of the time delay between sizing and printing the first layer.

Jeremy, unless you can't adequately handle it, I would dispense with the glyoxol and go straight to the formalin. There are some sources out there for it, but I am not going to publicly point people to them as it is a chemical used in the grug trade (at least I've been told) and is a SOB to boot, so I don't want people to casually get their hands on it.


---Michael

I refrigerate my glyoxal. And, I make sure it is fresh.

I have never had a problem. Also, I don't get involved in GRUGS. LoL.

PE

[donbga]

I'll never use glyoxol again. Works fine if it is very fresh, but as the bottle ages, it causes the gelatin to yellow unacceptably, regardless of the time delay between sizing and printing the first layer.

Jeremy, unless you can't adequately handle it, I would dispense with the glyoxol and go straight to the formalin. There are some sources out there for it, but I am not going to publicly point people to them as it is a chemical used in the grug trade (at least I've been told) and is a SOB to boot, so I don't want people to casually get their hands on it.


---Michael

A 2.5% solution of gluteralhyde works great, never yellows, and leaves the paper smooth as a babies butt.

[Photo Engineer]

A 2.5% solution of gluteralhyde works great, never yellows, and leaves the paper smooth as a babies butt.

And, it smells up the DR as bad or worse than formalin. There is a law suit in Australia over glutaraldehyde.

PE

[donbga]

And, it smells up the DR as bad or worse than formalin. There is a law suit in Australia over glutaraldehyde.

PE

That's not been my experience with it. I use very small amounts and keep containes closed.

[Photo Engineer]

As I've said over and over, "Use what works for you".

PE

[Michael Mutmansky]

I find glut to be much less offensive (odor-wise) than formalin, but I think formalin works better. I think both work better then glyoxol by a large margin, and the $50 spent on a respirator is a small price to pay for real consistant gelatin.

In truth, a respirator should probably be used with all of these, but many people don't with glyoxol, and some don't with glut. Basically, if you have to use the same precautions, then use what you think works best for your purposes...


---Michael

[donbga]

As I've said over and over, "Use what works for you".

PE

I should rephrase my initial post. The glut is a 2.5% concentration to start with. A much smaller % ends up in the gelatin. I'd have to look at my notes to be sure but as I recall the amount of 2.5% glut added to the gelatin (3%) is 1.5 ml per 150 ml of gelatin. But please don't hold me to that as I'm working purely on memory.

Never the less glut should be handled with caution, always with eye protection, plenty of ventilation and a respirator.

[Kerik]

I tried the Black Magic glut and found it much less effective than formalin or glyoxal. B.M. hardened gelatine resulted in greatly increased pigment staining. I've heard the same results from others. I've never had problems with glyoxal if I use the sized paper right away. However, I often have sized prints laying around for a while before I gum them, so I routinely use formalin for my work and glyoxal in workshops.

[donbga]

I tried the Black Magic glut and found it much less effective than formalin or glyoxal. B.M. hardened gelatine resulted in greatly increased pigment staining. I've heard the same results from others. I've never had problems with glyoxal if I use the sized paper right away. However, I often have sized prints laying around for a while before I gum them, so I routinely use formalin for my work and glyoxal in workshops.

Black Magic glut is the wrong glut to use. It contains, as I understand it, sulfates which causes problems. Photographers Formulary now sells glut without sulfates.

[Photo Engineer]

Well, I remind you again of the lawsuit over the use of glutaraldehyde which is pending in Australia. There was a lengthy thread on this subject over on Photo Net about a year ago.

In fact, X-Ray film processing was revised (IIRC) to remove the glutaraldehyde over this very suit. The fumes are not immediately annoying as are those of formalin, but they are quite bad over the long haul, from what I understand.

I don't like the odor of Glutaraldehyde or Succinaldehyde not to mention Formaldehyde. Glyoxal works for me and the odor is not objectionable when I have a whole room full of coatings hanging up to dry. And, the material is hard within 2 - 4 hours.

I have had some hardeners set the gelatin in the can before I can begin coating. Glyoxal does not do this unless the pH goes too high.

I remind you of another hardener that is not often mentioned. That is mucochloric acid. I have used that a lot, but not recently.

PE