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|
| Water 125F/52C | 600 | ml |
| Sodium Sulfite (anhydrous) | 75 | g |
| Acetic Acid 28% | 235 | ml |
| Boric Acid (crystals) | 37.5 | g |
| Potassium Alum | 75 | g |
| Cold water to make | 1000 | ml |
| Mixing Instructions: Add chemicals in specified sequence. Allow solution to cool after mixing. To make 28% acetic acid from glacial acetic acid, dilute 3 parts of glacial acetic acid with 8 parts water. Use boric acid crystals as specified, do not use powder as it is extremely hard to dissolve. A 30% hypo fixer solution is made by dissolving 300g of Sodium Thiosulfate (Hypo) in sufficient hot water to make 1L. Allow to cool. |
| Dilution: Add 1 part hardener to 4 parts 30% hypo fixer solution |
| Usage: Fix film for 10 mins or double the clearing time. |
Notes This hardener can be added to other commercial acid fixers, but should be tested prior to use on important work. Fixing time will be less with modern rapid fixers; however, hardener will increase fixing times listed on the bottle. |
