I use Ilford Hypam, it's a rapid fixer, different from Ilford Rapid Fix. I think IRF may have some hardner added, not certain, but Hypam serves the same purpose, it's also a good deal cheaper than IRF.
I use Ilford Hypam, it's a rapid fixer, different from Ilford Rapid Fix. I think IRF may have some hardner added, not certain, but Hypam serves the same purpose, it's also a good deal cheaper than IRF.
Ilford Rapid Fix contains no Hardener. From The IRF MSDS the list of ingredients is:
Sodium Sulfite
Acetic Acid
Water
Ammonium Thiosulfate
Clearly, No hardener is listed in the IRF MSDS
In addition Ilford, state:
1. The current version of Hypam Fixer is rebadged Ilford Rapid Fixer
2. There is no hardener in either IRF or Hypam - if you want hardener you must add it yourself.
Tom, you're right about the hardener aspect, however Hypam also has Boric acid in it, whereas I believe that Rapid fix does not. Also Rod Parsons of Ilford was in my darkroom about a month or two ago and I think he mentioned that there was some difference but that Hypam was fine for use with the Ilford archival wash system.
There are three very minor differences between Hypam Fixer and Ilford Rapid Fixer.
1. Hypam Fixer contains some Sodium Acetate (the sodium salt of acetic acid) the Sodium Acetate would tend to act as a pH buffer for the Acetic acid.
Ilford Rapid Fixer does not contain Sodium Acetate.
2. Hypam Fixer contains some Boric Acid, Ilford Rapid Fixer does not.
3. The pH of the Hypam Fixer concentrate is listed as 5.1 The pH of the Ilford Rapid Fixer concentrate is listed as 5
Sounds to me like these two acid fixing concentrates should function pretty much the same. Buy the cheapest one - or buy some 60% Ammonium Thiosulfate instead.
One last thought regarding boric acid in fixers. At one point in time, Ilford advocated the use of boric acid as the only source of acid in an acid hardening fixer. They believed that the boric acid would enhance the shelf life of a hardening fixer.
However, use of a hardening fixer is counter productive if you are trying to fix and wash your fim and prints to archival standards.