Rapid fixer formula wantedgreenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
Can someone provide me with a formula for a non hardening rapid fixer. I can't seem to find one in all the usual books.
Preferably I'd like the formula for Ilford Universal fixer or similar where I mix a stock and further dilute from that for use.
Ilford lists the ingredients on their bottle but I don't know what proportions I'd use.
Thanks for any help
-- Mark Bau (email@example.com), May 02, 2000
Just off the top of my head, Ammonium Thiosulphate at 100gms to the litre plus a few grammes of an acidifying agent like Sodium Citrate or Acetate seems to ring a bell.
I'll look it up properly tonight, if no-one else comes up with it first.
Fixer strength should be different for films and paper anyway. What do you want to use it for?
-- Pete Andrews (firstname.lastname@example.org), May 03, 2000.
I'd like a formula that allows for the 60 second paper fix routine as outlined by Ilford. Using Ilford Universal or Hypam I use the same strength for film or paper.
-- Mark Bau (email@example.com), May 03, 2000.
Photographer's Formulary T-4. They sell it as a concentrate that you dilute for use. Formula is not available. I'm lucky, as my local store stocks it.
This is the only fixer I've ever gotten excited about.
Film clears in 30 seconds. No kidding. Half a minute. Unbelieveable.
Papers: recommend fixing RC for 30 sec, FB for 60 seconds. Continuous agitation.
This is an alkaline fixer. Don't use an acid stop bath with it. Just running water. Keeps the process alkaline all the way through.
-- Charlie Strack (firstname.lastname@example.org), May 03, 2000.
Well, I've been away and looked in my old copy of Ilford's formulary, and they don't publish the formula for Hypam. I did find a formula for rapid fixer in C.I.Jacobson's book "Developing" however:
200gms Ammonium Thiosulphate; 15gms Sodium Sulphite; 55ml of 28% Acetic acid; 7.5 gms Boric acid; 50gms Potassium alum; water to 1 litre.
The Potassium Alum is the hardening part, so you should leave this out. 55ml of 28% Acetic acid is about 20ml of glacial, and it's important to only add it after the Sodium Sulphite has fully dissolved.
Other fixer formulae use Potassium Metabisulphite instead of the Acetic acid and Sodium Sulphite. You can also replace the Ammonium Thiosulphate with 250gms of Sodium Thiosulphate plus 40gms of Ammonium Chloride (this makes Ammonium Thiosulphate in solution). The British Journal of Photography Alamanac for 1963 recommends solely using Boric acid as the Acidifying agent. Jacobson also gives the formula for a super rapid fixer using Sodium Thiocyanate, which fixes in seconds apparently.
So it seems that fixer formulae are pretty much mix'n'match really, as long as you've got the 3 basic components.
Silver Halide solvent: Sodium or Ammonium Thiosulphate; Potassium or Sodium Thiocyanate; Potassium Cyanide (not recommended for obvious reasons)
Acidifier: Potassium Metabisulphite; Sodium Sulphite + Acetic Acid; Boric Acid.
Hardening agent: Potassium or Chrome Alum; Formalin.
-- Pete Andrews (email@example.com), May 04, 2000.
Rats! I made a mistake with the quantity of Potassium Alum in the above formula. It should be 15gms not 50gms. Apologies.
-- Pete Andrews (firstname.lastname@example.org), May 05, 2000.
Here is the formula for TF-3. It is an akaline fixer. Do not use a stop bath.
TF-3 Ammonium thiosulfate 57-60% 800ml Sodium sulfite anhydrous 60g Sodium metaborate 5g Add water to 1 liter. Dilute 1:4 for use.
-- William Marderness (email@example.com), May 11, 2000.