[pure-silver] Re: Wash aid lifetime
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Tue, 17 May 2005 14:08:37 -0700
>> dickburk@xxxxxxxxxxxxx
>
> According to the info I have from D. William Reichner
> writings is that
> the capacity of the Hypo Eliminator can be more than
> doubled by pre
> washing your prints or film for 3 minutes before the
> clearing bath. He
> also claims that by adding 1 gram of Potassium Iodide per
> liter to your
> fixer greatly helps the Hypo eliminator to do it's job.
> He also
> suggests a different hypo eliminator:
> water 500ml
> Hydrogen Peroxide (3.0%) 125 ml
> Ammonium Hydroxide (3.0%) 100 ml
> water to 100 ml
>
> I got this from "Dignan Photographic 150 do-it-yourself
> formulas"
>
> this formula was originally created for micro film which
> is more
> difficult to clean than normal film.
>
> Dennis Purdy
>
This refers to the ancient Kodak Hypo Eliminator, a very
different formula from hypo clearing agent. Hypo Eliminator
has not be recommended for decades because it does not
completely work and because it can damage some emulsions.
Kodak recommended bromide not iodide as an additive to
prevent leaving behind some products which cause staining.
Iodide is used in processing microfilm because a very
small residue of Iodide in the film has been shown to
prevent some forms of oxidation of the silver. Two different
things.
Kodak HE-1 can be made from household Ammonia and
drugstore Hydrogen Peroxide, but, again, its no longer
considered a good treatment. BTW, I don't think it was ever
used for microfilm because of its tendency to cause pinholes
in the emulsion.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
