Re: How to reduce stain in pyro negatives>?

Sandy,

The following is repost of a repost on the Al-photo-process list a good
while back. Is this what you were looking for?

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I take the liberty of re-posting a post of Burkhardt about removing the
Pyro stain. I tried it, and it works like a charm,

Best,

Cor

-------- Original Message --------
Subject: Re: POP choices
Date: Mon, 03 Sep 2001 21:27:30 +0200
From: Burkhardt Kiegeland <burkhardt@einsundsein.org>
Reply-To: alt-photo-process-l@sask.usask.ca
To: alt-photo-process-l@sask.usask.ca

Here is the Kodak S6 formula for removing of stain:

Stock solution A:
Potassium parmanganate 5.2g
Cold water to make 1l

The permanganate has to be dissolved completely to avoid spots on the
neg.

Stock solution B:
Cold water 500ml
Sodium chloride 75g
Sulfuric acid, conc. 16ml
Cold water to make 1l

Caution: Never put the water into the acid, it will boil up!

Stock solution C:
Sodium bisulfite,
1% soilution, this means 1g for 100ml water

1. Harden the film (2-3min) in a hardener solution like 5-10% glyoxal
2. Wash for 5min
3. Bleach in equal amounts of A and B for 3-4min,
   the mix is of short shelf life
4. After bleaching put negative in solution C until
   all stain is removed
5. Wash thoroughly
6. redevelop under 100W bulb in a non staining developer of low alkali
   like D72 dilution 1:2. D76 does no good because of it´s high sulfite
   and low alkali which would dissolve the silver image

I did use this formula successful with some overstained Pyro negs a
couple
of times.

Burkhardt Kiegeland

www.lotusviewcamerea.at

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Don Bryant
Received on Mon Dec 1 21:43:50 2003