Re: Pt IV to Pt II

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From: Richard Knoppow (dickburk@ix.netcom.com)
Date: 02/14/03-12:46:50 AM Z


----- Original Message -----
From: "Clay" <wcharmon@wt.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, February 13, 2003 4:04 AM
Subject: Re: Pt IV to Pt II

> Is this the link: ?
>
>
>
/lists/alt-photo-process/2002/jun02/0175.
htm
> >
>
> > Someone, recently, posted a formula for a bleach used in
reversal
> > processing.
> > As I remember, it was Potassium Permanganate and Sodium
Bisulfate. I
> > actually cannot find any reference to this bleach. I
also think it was
> > referred to as a modified Kodak R9 bleach. My records
indicate the R9
> > employs Potassium di(or bi) chromate and Sulfuric Acid.
> >
> > Any ideas folks?
> > Thanks
> > Jack
> >
  I can't find either R-9 or modified R-9 but reversal
bleaches are all about the same. Here are two.
Bleach No.1
Potassium bichromate 5.0 grams
Sulfuric Acid 5.0 ml
Waer to make 1.0 liter
 As always, add the acid slowly to the water. Sulfuric
evolves a lot of heat when it goes into solution.

Bleach No.2
Potassium Permanganate 2.0 grams
Sulfuric Acid 5.0 ml
Water to make 1.0 liter

  The permanganate bleach softens the gelatin more than the
bichromate bleach.
  Alt processes people should be well aware of the hazards
of bichromate.
  After bleaching in either bleach the film should be
cleared in:

Clearing bath
Sodium bisulfite 50.0 grams
Water to make 1.0 liter

Sodium Sulfite or Sodium metabisulfite may be used weight
for weight for the bisulfite.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com

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