Re: Modifying PMK for rotary use?

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From: Tox Gunn (tox@remarque.org)
Date: 01/10/01-10:16:50 AM Z


> Tox,
>
<snip>
> I eventually noticed that the presence of Ascorbic Acid
> in this C solution shortened considerably its life,
> so this is what I do, working fine for me
> (4x5 FP4+ developed in rotary Jobo 2509 reel,
> 70F /21C, about 7'):
>
> Mix 200 ml of C solution as below (keeps indefinitely):
> Deionized Water 200 ml
> KBr 0.5 g
> EDTA 1.5 g
>
> When wanting to prepare the developer, mix
> on the spot a 1% fresh solution of Ascorbic Acid
> (to be dumped after partial use):
> Deionized Water 100 ml
> Ascorbic Acid 1 g
>
> Then, to mix 1000 ml of ABC+ working solution:
> Deionized water 1000 ml
> C solution 10 ml
> Ascorbic Acid sol. 10 ml (=0.1 g of Ascorbic Acid)
> Standard PMK A 25 ml
> Standard PMK B 30 ml
>
> In this way, in a liter of working solution you have:
>
> Pyrogallol 2.5 g
> Metol 0.25 g
> Sodium Bisulfite 0.5 g
> Sodium Metaborate 9 g
> Ascorbic Acid 0.1 g
> Potassium Bromide 0.025 g
> EDTA 0.075 g
>
>
> I have no general fog and a good stain (I also mix and
> use TF-2 alcaline fixer), even if I suspect that a lesser
> amount of KBr and Asc. Acid could be experimented
> to get an ideal equilibrium between overall fog
> and pyro stain, related to one's specific
> working variables.
>
> Francesco Curcio
> Milano Italy
>
Wonderful, thanks for the feedback! I'm surprised
that the Ascorbic is prone to going off, but glad
to be forewarned..;)

I'll give this a shot...

Tox


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