As a follow-up to a previous post asking wether or not a 2% sodium
sulfite was the proper formula for making a home-made hypo elimintor,
I'll offer two things:
1) there are possible problems associated with using sodium sulfite as a
hypo eliminater if the film isn't completely fixed.
2) Here is Kodak's formula Hypo Eliminator HE-1 (a much safer alternative)
Kodak Hypo Eliminator HE-1
Avoirdupoids Metric
U.S. Liquid
Water 16 oz 500 ml
Hydrogen Peroxide 4 oz 125 ml
Ammonia solution ** 3.25oz 100 ml
Water to make 32 oz 1 litre
CAUTION: Prepare the solution immediately before use and keep in an open
container during use. Do not store the mixed solution in a stoppered bottle, or the gas evolved may break the bottle.
** Prepared by adding one part of concentrated ammonia (28%) to nine
parts water.
Treat prints with HE-1 or wash them for 30 minutes at 18-21 C (65-70 F) in running water. Immerse prints about six minutes at 20 C (68 F) in HE-1. Finally wash 10 minutes.
Life: About 40 8x10 prints or equivalent per US gallon. (10 per litre).
*********
Comments from my part: There are a few alternatives: I prefer to buy
Kodak Hypo CLearing Agent in the 5 gallon size and mix it up to make
one gallon (US) of working concentrate and I dilute the concentrate
1 : 4 as I go. I mix up a litre (about a pint) for every session and
discard at the end of the session. When purchasing large quanities of
chemicals, the price per dose drops quite a bit.
An alternative to the above formula might be to mix up the entire
HE-1 formula without the hydrogen peroxide and add the H2O2 at the
beginning of the session, otherwise, use a container with a floating
lid.
How it works: most developpers are oxidants, most fixers are anti-
oxidants. Hydrogen peroxide neutrlises the anti-oxidising effect of
most fixers while the ammonia (a very weak developping agent)
neutralises the acidity most fixers like to work in.
Note for people outside the US: though imperial ounces are smaller
than US ounces (and imperial gallon are bigger than US gallons), the
formula works for itself: you'll end up with 32 imperial ounces of
