U of S | Mailing List Archive | alt-photo-process-l | Re: Archival washing at home

Re: Archival washing at home

Thanks to Richard and John for the suggestions.  Looks like I've got some
shopping to do...

Camden Hardy


On 9/24/07 4:21 PM, "Richard Knoppow" <dickburk@ix.netcom.com> wrote:

> ----- Original Message -----
> From: "John E. Simmons" <productions@johnesimmons.com>
> To: <alt-photo-process-l@usask.ca>
> Sent: Monday, September 24, 2007 8:37 AM
> Subject: Re: Archival washing at home
>> I don't know for sure, and I don't really have a way to
>> test.  However, Ilford for their traditional materials,
>> recommends multiple changes of water in a tray.  It would
>> seem that alt process would be the same - although perhaps
>> a few more changes than for silver gelatin.  The pump helps
>> keep the prints separated, and in a large tray with several
>> liters of water, it seems to wash just fine.  A test with a
>> hypo test kit shows no residual hypo - again with silver
>> gelatin.
>> j
>> Camden Hardy wrote:
>>> John,
>     Ilford's recommendation is really to conserve water
> although successive baths _with constant agitation_ may
> result in better washing than in some running water washers.
> For single prints a Kodak tray syphon works fine. The tray
> should be larger than the print to allow circulation of the
> water. Care must be used to prevent prints from clinging to
> the bottom.
>     I am not at all sure if the process of washing for
> alternative materials is the same as for silver-gelatin. For
> conventional S-G coated on untreated paper (not RC) the
> washing out is partially a diffusion process, mostly for the
> emulsion, and partially frictional for hypo bound to the
> paper fibers. It is the latter that results in the very long
> wash times for "fiber" based paper. For silver-gelatin the
> wash rate is also dependant on the pH of the emulsion
> relative to its isoelectric point and the pH range over
> which white alum hardener acts as a mordant. This may not
> apply to the paper fibers.
>     It was discovered nearly fifty years ago that Sodium
> Sulfite acts as an ion exchange medium for hypo. It is very
> effective for gelatin emulsion but much less so for the hypo
> stuck to the paper fibers. It _may_ be of use in alternative
> printing process but I don't know what effect the sulfite
> might have on some of them. Certainly it would not be
> suitable for materials like Cyanotype which are bleached by
> alkaline solutions.
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@ix.netcom.com