[pure-silver] Re: Adding Pot Bromife to PC-TEA
- From: "John Black" <jblack@xxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 6 Jan 2005 15:50:19 -0500
> Ascorbate solution in presence of salicylate keeps MUCH better at pH
> 10 than pH 8. So you can make a concentrate of ascorbate, salicylate,
> Dimezone S, sulfite, and suitable alkaline agent(s) to make pH of
> 10. When using, you can dilute this with water, and add a separate
> solution of boric acid, whose proportion is adjusted so that the
> resulting pH falls in your desired range. The buffering agent for the
> final target pH may be present in any part or diluting water.
I am still trying to avoid water in my PC concentrates for storage prior to
dilution and use. Perhaps I could use the same solution A (PC in non-polar
solvent) and use different solution B (buffer and sulfite) for film and
paper. Film solution B could be borax or Tris/borate pH 8.3 and paper could
be carbonate/boric acid pH 10.0, both diluted with water and using the same
PC solution A.
>
> I used to experiment this before, but these days I just accumulate
> films and mix a batch of fresh solution each time... It's more fun to
> print than develop films...
I haven't done much of either lately. Too lazy to go shoot.
JB
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