Fixer from Scratch

[grain]

I was given a couple of 1lb. bottles of crystalline hypo (sodium thiosulfate) and tried to construct my

own fixer from it. I began with 250ml distilled water and just kept adding until it would no longer take

up into solution, then I added just a tsp. of sodium sulfite anhy. and brought the total to 500ml. (Yes, I

have no scale.)

It works well, and fairly fast clearing but leaves the unwanted magenta stain worse than anything I've

used. Any suggestions? Should I doctor it further or just live with it?

Thanks in advance to the old gangsters.

A.

[frank.schifano]

Maybe a little more sulfite would help with the magenta dyes in TMAX films, but it's not necessary. Other films, notably Tri-X, have a slight tint to the support material that will not wash out. To be on the safe side with TMax films, fix for 3x the clearing time rather than the usual 2x used for conventional films. It couldn't hurt. The magenta dye will diffuse out of the film with just a plain water soak with occasional agitation. If there is any dye left in the film after a thorough wash, simply immerse the film in a bath of standing water at processing temperature. The dye will diffuse out in a few minutes.

[rodeo_joe1]

It's not Thiosulphate that clears the magenta dye from (presumably) Tmax. Kodak recommend a strong sulphite - metabisulphite bath to clear it, AKA kodak fixer clearing bath. A bath that nobody ever thought was a necessity until Tmax was introduced. Hmmm! Strange coincidence or what?

 

Anyway. Try putting more sulphite and some metabisulphite in your home-brew fixing bath and see what happens. A teaspoonful of sulphite in 500ml is nowhere near enough to clear the Tmax "blues".

 

BTW, fixing baths were traditionally made acidic (hence the metabisulphite) to lengthen their working life and prevent any tendency to staining. An acidic bath also re-polymerises gelatine after it's been softened by an alkaline developer, thus toughening the emulsion. Of course this makes fixer products slightly more difficult to wash out of the "closed up" emulsion, but hey! Everything has a price.

[grain]

Thanks.

Yea, this was an effort to make my darkroom user friendly to my nostrils.

I have good ol' kodak hardening fix on hand, as well as ilford rapid. But as they decay they

stink.

I washed the heck out of it but still pink. I'll live.

It's the old neopan SS. Which I've rediscovered as a guilt-free alternative when shooting all

the time. ($2/roll)

I'll up the sulfite, and thank you gentlemen.

[keithostertag]

Hey Alexander- a heaping teaspoon of sodium sulfite is enough for a liter of hypo. A little more won't hurt, but it is only needed as a preservative. If you mix your hypo with water as a one-shot or for short periods you probably don't need it at all. If you look at past photo.net archives you will see a lot of discussion about the magenta cast. If it bothers me I put the dried film in the sun for an hour or so and that takes care of it. If you have the penta crystals you only need 240 grams (about half a cup or two handfuls) of hypo per liter of hot water (125 degrees).

[User_502260]

If the smell is a problem you can order odorless fixer from Freestyle.