Re: formulight + hardener on plait glass

From: Ryuji Suzuki <rs@silvergrain.org>
Subject: Re: formulight + hardener on plait glass
Date: Mon, 13 Sep 2004 14:22:02 -0400 (EDT)

> Troop recommended alkaline glutaraldehyde hardener in Film Developing
> Cookbook. That would work effectively, but for emulsion additive,
> glutaraldehyde can be added as a dilute acidic solution and is still
> highly effective. (Glutaraldehyde lasts very long in acidic solution
> but doesn't last at higher pH.)

Actually, formulary document says its pH is 3. At this pH
glutaraldehyde should keep for several month at least.

> I have not tried it, and I don't have information on it. If it doesn't
> have warning about its fume, it's probably chrome alum type hardener,

Formulary document says it can be added to a Dektol type developer.
So it's not chrome alum.

Other hardeners I mentioned, bis(vinylsulphonylmethyl)ether, and
s-triazines (2,4-dichloro-6-hydroxy-s-triazine) needs not be stored at
pH of 3, and these hardeners is best used near neutral or slightly
alkaline pH, so... unless they went for less common hardener, I'd
guess it's most likely glut based.

There are a couple of ways to test for glut, if anyone is really
interested in reverse analyzing what Formulary did. But for practical
purposes, glutaraldehyde or 2,4-dichloro-6-hydroxy-s-triazine would
work well.

--
Ryuji Suzuki
"You have to realize that junk is not the problem in and of itself.
Junk is the symptom, not the problem."
(Bob Dylan 1971; source: No Direction Home by Robert Shelton)