What are recommendations for the dark room to process X-ray film?
In this article:
- Clean Processing Tanks Regularly to Prevent Contamination: Use hot water and soap or appropriate chemical cleaners—like acetic acid for polyester tanks or nitric acid for stainless steel—to maintain hygiene and avoid film defects
- Avoid Finger Staining with Proper Hygiene Practices: Rinse hands immediately after contact with developer. If staining occurs, use a potassium permanganate and sulfuric acid solution followed by fixer and soap to clean skin safely
- Treat Hard Water to Prevent Chalky Film Deposits: Hard water can cause insoluble calcium deposits on films. Soften water by filtering or boiling before mixing chemicals, and remove deposits with a diluted glacial acetic acid solution
- Use Environmentally Friendly Cleaning Agents When Possible: Products like Devclean and Fixclean are designed for darkroom use and offer effective, eco-conscious alternatives for maintaining clean processing environments
- Follow Material-Specific Cleaning Guidelines: Never use hydrochloric acid on stainless steel tanks, as it can cause corrosion. Always match cleaning agents to tank materials to ensure safety and longevity
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.