Re: Hypo Clear
Richard Knoppow (dickburk@ix.netcom.com)
Fri, 14 Nov 1997 00:12:21 -0800
At 03:05 PM 11/13/97 -0700, Richard Sullivan wrote:
>Good Ole Jack Fulton says:
>
>>It made me wonder about hypo clearing again after years. i think it was
>>Patrick Dignan who first tested hypo clearing products/agents and came
>>up w/a recipe which I've lost. But, if memory is correct, he noted that
>>the product Hustler was the best in that it was a detergent
>>(surfactant). If anyone has info on the 'types' of hypo clearers, I'd
>>appreciate it.
>>As I understand it there is :
>>1. The 1st Kodak one w/Ammonia and Hyrogen Peroxide
>>2. The one noted above
>>3. Perma wash, which employs both amonium and sodium sulfites
>
>Funny you should ask -- and BTW, you are showing your age!
>
>>>>>
>>From Dignan's 1972 $2.00 self published book of formulas - well stained I
>might add:
>
>Substitute Fromula for Hypo Clearing Agent
>
>Water 1 Liter
>Sodium Sulfite 20 grams
>Sodium Bisulfite .2 grams
>
>The sodium bisulfite is only in the formula to lower the ph to 7-7.5 to
>prevent softening of the film
>
><<<<
>
>His 1977 self pub ($10.00 this time and enlarged) has a discussion of
>clearing and points to Crabtree and Henn's Kodak Communication 1790 as a
>source for the history of it.
>
>Dick Sullivan
>
>Bostick & Sullivan
>PO Box 16639, Santa Fe
>NM 87506
>505-474-0890 FAX 505-474-2857
>http://www.bostick-sullivan.com
>
>
>
I have a citation to this paper from another source and will try to find
it at the library on next week. I have been going over some of Crabtree's
old papers recently. There is a lot of interest there. He and his fellows
at Kodak did very thorough research into the fixing and washing process
over perhaps a thirty year period.
----
Richard Knoppow
Los Angeles,Ca.
dickburk@ix.netcom.com