BKF-2 Quick Acid Fixative
Quick acid fix for technical films (aerial photography, X-rays) and standard film—5–7 minutes.
About Fixage
BKF-2 Acid Rapid Fixer is used for accelerated image fixation, primarily on special technical films, such as aerial photography and X-ray films. It can also be used to fix standard small- or medium-format film.
Character
A snarky, quick-witted type.
How to Prepare and Use
- 1Pour about 700 ml of hot water (60–70 °C) into a 1-liter container and dissolve the contents of the large package (250 g of crystalline sodium thiosulfate) in it.
- 2Once the salt has completely dissolved and the solution has cleared, add the contents of the small packet (17 g of sodium metabisulfite) and dissolve it completely.
- 3Pour in the contents of the medium-sized packet (50 g of ammonium chloride), dissolve it, and let the solution cool to room temperature.
- 4Bring the volume of the solution to 1 liter and filter it if necessary.
- 5Cure the film for 5–7 minutes at a temperature of 20 °C.
Recipe for 1 liter

250 g
Crystalline Sodium Thiosulfate (Large Package)

50 g
Ammonium chloride (medium package)

17 g
Sodium Metabisulfite (Small Package)
Procedure for dissolving in 700 mL of hot water (60–70 °C): large packet (thiosulfate) → small packet (metabisulfite) → medium packet (ammonium chloride); then bring the volume up to 1 L.
Chemical structures: PubChem (public domain)