Universal neutral fixer
Silberra FIXER N (neutral fixer) is the most simple one-component fixer suitable to process any silver based negative photographic materials: photo film, photo papers or photo plates. Silberra FIXER N is ideal to use with fine grain and extra fine grain negative materials. Silberra FIXER N is strongly recommended to use with colouring developers also (like PYRO HD, pyrocat, Microl, amidol-based developers, etc.).
Preparing Working Solution
Working solution is prepared by pouring the contents of the pack into water while continuously stirring the solution (use glass stick or special plastic stirring stick for chemicals). Distilled or filtered water is strongly recommended.
The method of preparation is as follows:
1) Warm 400-600 ml of water up to 40-45 Celcium degrees (use mix of hot and cold water, or use microwave for warming up the water).
2) Pour contents of pack #1 into the water while stirring until the powder is completely dissolved.
Add some distilled water into solution up to 1 litre in total volume. Note that dissolving sodium thiosulfate will lower the initial temperature of working solution by approximately 10C degrees.
Allow the solution to cool to room temperature, nominally 20-22 C; wait for 1 hour prior to using it. Filtering the solution is not obligatory but recommended option.
Silberra FIXER N stock solution fixing time is
10-12 minutes for b&w photo film,
15-20 minutes for baryta based papers,
10-15 minutes for RC based papers.
Ideal fixing time for each specific (and/or unusual) b&w film is calculated as triple whitening time. Whitening time is the time unexposed film needs to become absolutely transparent since immersed into fixing solution. Use lab timer and tweezers to get whitening time for a small stripe of unexposed film you're going to fix. Don't forget to triple that time to get real fixing time.
There is no need for additional tests to get fixing time for photo papers: always use the above shown time.
1 liter of Silberra FIXER N can be used to fix up to 15 rolls of film or 30-35 sheets of 18x24 cm photo paper.
Never use the same working solution to fix photo paper and film. Don't use Silberra FIXER N for warm tone photo paper.
Keep your Silberra FIXER N working solution in a cool, dry and dark place. Keep away from children. It is optimal to store your working solution in opaque, chemically inert and tightly sealed containers with minimal air space in order to reduce oxidation. Strong ammonium scent may indicate that fixer working solution is completely depleted and shall not be used any longer.
Expiry date/ Shelf life
Shelf life of Silberra FIXER N is 24 months while in original sealed packs. Silberra FIXER N working solution can be stored up to 3 months past the date of dilution; for partly used working solution storage period is no longer than 2 days.
Silberra developers and fixers must be disposed of in accordance with the rules and regulations of the country they are used in. Concentrated developers could be toxic and may harm the environment unless disposed in appropriate manner. Silberra recommends to use special disposal services provided by correspondingly licensed organizations which are eligible for photographic chemistry recycling/disposal.