Chemicals

Household substitutes

Many processing chemicals can be exchanged by common household products and get similar results. These substitutions are intended as a quick replacement when you run out of one of them or if you don't have access to them at all. For assured quality, use proper formulations.

Stopper

Used in the stop bath, it quickly halts film development. Can be replaced by:

• vinegar: one part common white vinegar to 4 parts of water = 1% acetic acid solution
• citric acid: 4 teaspoons of citric acid for one liter of water

Washer

A.k.a. Washaid, Hypo Clearing Agent. Can be replaced by:

• washing soda: a mild water solution of sodium carbonate ("a few table spoons of Arm and Hammer washing soda per gallon")
• salt: a mild water solution of sodium chloride ("one level tablespoon in a quart of water followed by the usual procedures after a wash aid")

Fixer

Fixed, a.k.a. Hypo, is mainly sodium thiosulfate (previously called hyposulfite - hence the name) with additives. You can't find hypo in the supermarket.

"You can, however, sometimes find it where pool chemicals are sold. Sodium thiosulfate and sodium sulfite are both sold as chlorine reducers; the trick is determining which one you have when you find a product sold for that purpose. The easiest way is to ask for the MSDS, though you're also likely to find the information on the package labeling, if you have a magnifying glass handy. If you can get a look at the contents of the package, it's easy to tell -- sodium sulfite is usually sold as anhydrous, a white powder with a consistency rather like table salt, while sodium thiosfulate is usually sold as pentahydrate, aka "rice crystals" -- as the name implies, they're crystals shaped like grains of rice, though in my experience usually somewhat larger; they're clear, irrgularly polygonal in cross section, usually with broken ends."

Sources

• Thread on photo.net - Homemade washer
• f295 DIY forum - Fixer alternative
• Thread on APUG - Homemade stopper

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