What are recommendations for the dark room to process X-ray film?
Cleaning of tanks: Whenever the processing solution is renewed the tank must be cleaned, preferably with hot water and soap. If this proves inadequate, polyester tanks can be cleaned using a bleach solution (100-200 ml/litre of water), hydrochloric acid (10 ml/litre of water) or acetic acid (50 ml/litre of water). Stainless steel tanks may be cleaned with a solution of nitric acid (10 ml/litre of water) or acetic acid (50 ml/litre of water). Hydrochloric acid must never be used for stainless steel tanks. There are industrial cleaning agents on the market (for example Devclean and the, environment-friendly, Fixclean), specially developed for cleaning of darkrooms.
Stained fingers: Brown stains on the fingers can be avoided by rinsing the hands in water whenever they come into contact with developer. If fingers do become stained, they should be immersed in a solution of:
a. 1 litre of water
b. 2 gr of Potassium-permanganate
c. 10 ml of concentrated sulphuric acid
Next the hands should be rinsed in an acid fixer solution, and finally washed with soap and water.
Chalky water:
If hard, chalky water is used for mixing the solutions, troublesome processing faults may occur. Calcium salts may, in the presence of carbonates and sulphites, result in a whitish deposit on the films which is insoluble in water. To prevent this, the diluant can be softened by using a special filter, or by boiling it first and letting it cool down before making up the chemical solutions. To remove chalk deposit from films, they may be soaked in a solution of 7 ml glacial acetic acid to a litre of water.