Where to purchase chemicals for mixing own developer

mshchem

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Ebay for sodium thiosulfate. I buy from small US dealers. I still have quite a collection of Kodak chemicals that are 40 years old that still work. If I was buying metal or hydroquinone I would think Photographers Formulary would be good.
Look on Ebay. I have had good luck.

There's no good reason to mess with old formulas that use hazardous chemicals. There's risk to the user and the stuff is a pain to get rid of.

You can make a lot of different developers with metol, hydroquinone, sodium sulfite and potassium bromide.

Kodak D-23 is just metol, sodium sulfite and water. Great developer.
 

koraks

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And don't forget the vitamin C powder (eg drugstore). Very useful indeed for your caffenol or (my preference) xtol variants. A little phenidone goes a long way too; check ebay.
 

Donald Qualls

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Hmm. So something in coffee, that's more present in cheaper instant or robusta beans, is acting as a developing agent in addition to caffeic acid, or augmenting the caffeic acid. Given that the tests in that other thread were done with a Caffenol C variant, and vitamin C is itself a developing agent, we're no longer even sure caffeic acid by itself is a developing agent at all (that is to say, most likely you'd get some development if you just left the coffee or caffeic acid out of the Caffenol -- doesn't Mytol use ascorbate as the only developing agent?).

Has anyone tested pure caffeic acid with alkali, and no secondary developing agent?
 

Donald Qualls

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koraks said:
No, it also contains a little phenidone.
Click to expand...

Okay, haven't looked at that formula. But the ascorbate stands in for hydroquinone, and caffeic acid is usually said to be similar to cathechol, which also stands in for hydroquinone at times. Makes me wonder what else in coffee (robusta and/or instant) is standing in for an aminophenol.
 

Raghu Kuvempunagar

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Donald Qualls said:
Makes me wonder what else in coffee (robusta and/or instant) is standing in for an aminophenol.
Click to expand...

It seems Pyrocatechol is a degradation product of coffee during roasting:
https://www.nature.com/articles/s41598-020-59380-x

Roasted coffee contains not only Pyrocatechol but also Hydroquinone and Pyrogallol according to this:
https://books.google.co.in/books?id=Rgs_rVOceZwC&pg=PA114&lpg=PA114&#v=onepage&q&f=false

Robusta has these developing agents in relatively higher concentration than Arabica.

It could be the combined activity of these agents that we see in Caffenol developers.
 

Donald Qualls

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Actual pyro in my coffee (well, not so much my coffee, I drink the good stuff, but in instant). That would explain the stain if you make Caffenol without the ascorbate.
 

koraks

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I don't think the concentrations of pyrocatechol and pyrogallol in coffee arw sufficient to add much to the developing potential. If they were high enough for this, the coffee would be rather toxic and carcinogenic.
 

beemermark

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BHphotovideo and Adorama. D23 real easy to mix and works great with most films
 

Raghu Kuvempunagar

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koraks said:
I don't think the concentrations of pyrocatechol and pyrogallol in coffee arw sufficient to add much to the developing potential. If they were high enough for this, the coffee would be rather toxic and carcinogenic.
Click to expand...

You're probably right. There's superadditivity of all these agents with ascorbic acid and caffeic acid though.
 

Raghu Kuvempunagar

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We should request Formulary to introduce a developer enthusiast's chemistry kit consisting of small amounts of different developing agents like metol, hydroquinone, catechol, ascorbic acid and other useful chemicals like carbonate, metaborate, sulphite, etc so that users can brew small volumes of different developers.
 

Donald Qualls

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Does sound like an opportunity, though they'd have to mark the kit up a good bit over the price of the components to make anything at it, and it would compete with their own developer mix kits, to some extent. Anyone likely to buy it would be ahead buying the individual chemicals in reasonable quantity, if they have a clue (and if they don't, they should probably stick to "mix the contents of bags A, B, and C, in that order, then make up to 950 ml").
 

ChristopherCoy

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Donald, it seems like you're volunteering to lead up the group buy for us. Are you volunteering? Cause it seems like you're volunteering.
 

Donald Qualls

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No capital here, never mind facilities to repackage chemicals. Not to mention, I work full time and commute an hour each way, so have no time to repackage chemicals.
 
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