Defcat 2

jdef said:

TMY

Jay

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What does the stain look like?

Looks like I'll have to buy some propylene glycol...

Thanks Jay. I've got several tons of chemisrty to go thru, including a bottle of Rodinal with the rubber stopper, but when I run out, I look forward to trying this one as well as the Rapid.

jdef said:

You can make the developer up without the glycol, but I don't know how long the concentrate will last in an aqueous solution, even without the alkali.

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In my experience pyrocatechin does rather well in acidic solution, and deteriorates rapidly in alkali - q.v. what the Pextral solutions look like after use. So I'll give it a go when I get home.

I kept a quote from a post by Sandy from some time ago. It's a 2-bath catechol (a.k.a. pyrocatechol, catechin, pyrocatechin) formula.

I haven't used it. Has anyone given it a try?

This was in the context of people wondering what is/was in Dixactol, Barry Thornton's 2-bath proprietary catechol formula.

"Barrry Thornton published an article in Professional Photographer several years
ago which included a split-development formula based on pyrocatechin that
he claimed to be stronger staining than PMK, with a non-actinic brown
stain (neutral efffect on VC papers).

Bath A concentrate
Pyrocatechin 10g
Sodium sulphite 2g
Potassium bromide 0.5g
Water to 100ml


Bath B concentrate
Potassium hydroxide 10g
Potassium bromide 0.5g
Water to 100ml

Working solutions of bath A and bath B are mixed 1:14 with water. He
recommends 4 minute development in each bath at 21 C, with agitation once
every 30 seconds in bath A, once every minute in bath B. No rinse between
baths."

jdef said:

The ratio of pyrocatechin to sodium sulfite in Thornton's developer is the same as the ratio of pyrocatechin to ascorbic acid in Defcat 2, so maybe a similar dilution of Defcat 2 would produce similar results?

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You are saying that the function of sodium sulfite is the same as ascorbic acid? ?