Formulary TF4 fixer

[axs810]

Can anyone explain to me why this type of fixer doesn't need a stop bath or hypo clearing agent? I've read that it's an alkaline fixer but I still don't understand why it doesn't need a stop bath (I still use water as a stop) or a hypo clearing agent.


What is a good archival wash time when using TF4? It's supposedly shorter but I don't know by how much...I generally do a vertical wash for 20min.




Any info is appreciated!


Thanks!

 

[Richard S. (rich815)]

I haven't used a stop bath for film for years with TF-4, which is what I've mostly used for the last 5-6 years, or any other fixer. Nor hypo clear.

 

[axs810]

How would I test for retained thiosulfate?

 

[Nathan King]

How would I test for retained thiosulfate?

Testing for retained thiosulfate requires the Photographer's Formulary Residual Hypo Test. It is an extremely easy product to use.

 

[axs810]

Interesting. I'll have to try it out sometime soon


Thanks for all the quick responses!


(If anyone else has any more info they can share about TF4 fixer please share )

 

[Gerald C Koch]

A hardening fixer which contains potassium alum like Kodak F-5 requires an acid stop bath to prevent aluminum salts from precipitating.