Kodak Rapid Fix vs Ilford Rapid Fix

ArtBarn · Dec 28, 2021

I'm hoping to get some understanding as to why Ilford says hardener can not be used with their rapid fix. They both are made from Ammonium Thiosulphate. Kodak also has Acetic acid and Ammonium sulphate in it. Ilford doesn't say what else it contains. What would happen if I added hardener to the Ilford product? Kodak is very hard to find now with many vendors not wanting to carry their chemicals. I have to switch but I use a large belt dryer and like a small amount of hardener in the rapid fix. Of course there seems to be no one to ask at either company! Thank you!

Mr Bill · Dec 28, 2021

ArtBarn said:
I'm hoping to get some understanding as to why Ilford says hardener can not be used with their rapid fix.

Hi, just as a guess I'd say it's likely that Ilford is running their pH too high for the standard hardener. Generally, I think that a potassium alum hardener needs to be used with a pH value a bit below 4.5, or so. (I'm going from memory; this may not be exactly right.)

Did you look up the aim value for Ilford's Rapid Fix?

halfaman · Dec 28, 2021

Ilford Hypam is the fixer designed to use with hardeners.

Ernst-Jan · Dec 28, 2021

As said before, if you want to use a hardener, get Ilford Hypam

Nicholas Lindan · Dec 28, 2021

You can also add hardener to the stop bath. That lets you keep an alkaline fix.

John Wiegerink · Dec 28, 2021

Nicholas Lindan said:
You can also add hardener to the stop bath. That lets you keep an alkaline fix.

If I were to use a hardener it would be by this method since I wish to stick with alkaline fixers. I'm just starting to shoot some Foma 100 and 200 from bulk in 35mm. I've heard of how soft the emulsion is and was wondering if I should use a hardener with my alkaline fixer via stop bath or just buy a fixer with hardener and use it just for Foma films. What ya think? JohnW

mshchem · Dec 28, 2021

ArtBarn said:
I'm hoping to get some understanding as to why Ilford says hardener can not be used with their rapid fix. They both are made from Ammonium Thiosulphate. Kodak also has Acetic acid and Ammonium sulphate in it. Ilford doesn't say what else it contains. What would happen if I added hardener to the Ilford product? Kodak is very hard to find now with many vendors not wanting to carry their chemicals. I have to switch but I use a large belt dryer and like a small amount of hardener in the rapid fix. Of course there seems to be no one to ask at either company! Thank you!

I use a modest Pako dryer and indeed without hardener prints stick to the belt. I don't know why Ilford rapid fix and hardener are not compatible. Hypam is what Ilford recommends with Hardener.

I still have several bottles of Kodak's rapid fix with hardener. I suspect there's other manufacturers out there.

mshchem · Dec 28, 2021

Nicholas Lindan said:
You can also add hardener to the stop bath. That lets you keep an alkaline fix.

Very good idea, lots of old formulas for this.

gone · Dec 28, 2021

John, I shoot a lot of Foma 100 and 400 and haven't seen a need for a hardener. Those negs seem as sturdy as any other of my B&W negs. They're both excellent films too, once you dial them in.

John Wiegerink · Dec 28, 2021

momus said:
John, I shoot a lot of Foma 100 and 400 and haven't seen a need for a hardener. Those negs seem as sturdy as any other of my B&W negs. They're both excellent films too, once you dial them in.

Thanks for the advice. I guess I'll just go "naked" without hardener and see how it goes. I'm just in the process of finding my EI with an old Zeiss Contaflex. I think the Foma films and the old Contaflex might just be made for each other. JohnW

ArtBarn · Dec 30, 2021

michael_r said:
This is correct. When a standard alum hardener is used the pH must be lowered, and the formulation and buffering of the fixer needs to allow for that. Ilford Rapid Fixer is not designed for this. Ilford Hypam is designed for this (its properties are otherwise essentially the same as Ilford Rapid Fixer).

Thank you for your reply. The hitch with Hypam is that old reliable standard Hypo Check will not work with it. Has anyone mixed their own formula to check when Hypam is nearing exhaustion?

ArtBarn · Dec 30, 2021

John Wiegerink said:
If I were to use a hardener it would be by this method since I wish to stick with alkaline fixers. I'm just starting to shoot some Foma 100 and 200 from bulk in 35mm. I've heard of how soft the emulsion is and was wondering if I should use a hardener with my alkaline fixer via stop bath or just buy a fixer with hardener and use it just for Foma films. What ya think? JohnW

Nicholas Lindan said:
You can also add hardener to the stop bath. That lets you keep an alkaline fix.

Would I put the same amount of hardener into the stop bath that I would put in the same quantity of Kodak Rapid Fix?

Nicholas Lindan · Dec 30, 2021

Kodak's formula for "Stop/Hardening Bath #3" from Anchell's Darkroom Cookbook
20 gm Sodium Acetate
30 gm Potassium Alum
10 ml Glacial Acetic Acid (or 48ml 28%)
Water to make 1 liter working solution

I imagine the acetate is there as a pH buffer (?). A hardening stop bath should never go alkaline or the P. Alum comes out of solution - with an alkaline fix you might want to have rinse baths before and after the stop/hardener.

There are mentions of using a hardening bath before the developer.

There are also hardeners that use formalin. I don't know much about them but they may be better suited for use with alkaline fixers.

Kodak Rapid Fix vs Ilford Rapid Fix

ArtBarn

Mr Bill

halfaman

Ernst-Jan

Nicholas Lindan

Advertiser

John Wiegerink

mshchem

mshchem

gone

John Wiegerink

ArtBarn

ArtBarn

Nicholas Lindan

Advertiser

Kodak Rapid Fix vs Ilford Rapid Fix

Advertiser

Advertiser

Privacy & Transparency

Privacy & Transparency