>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