Kodafix: mix up full gallon or smaller amount?

[ron917]

I'm almost ready to develop some B&W film at home. I developed and printed throughout my high school years and some college in school darkrooms, but that was a long time ago.

I tried searching, but couldn't find a clear answer:

Should I mix up a full gallon of Kodafix, or is it OK to mix up smaller batches?

A full gallon has capacity for 120 rolls of 35mm, if I'm reading the data sheet correctly. But it is likely to go bad long before I process 120 rolls.

If I mix up a quart instead, will the capacity be 30 rolls? Will the opened bottle of concentrate stay good until it's expiration date?

Or, should I just mix up the full gallon and do a clearing test before each use?

 

[MattKing]

If you are referring to the powder fixer, you need to mix up the entire package.

If you are referring to the liquid version, you can and should mix up smaller batches.

You can consider transferring the not yet diluted concentrate to smaller, full bottles.

 

[mehguy]

With the liquid, just mix up what you need. The concentrate has a much longer shelf life compared to the diluted kodafix.

 

[ron917]

Thanks to both of you.

I have the liquid Kodafix. I'll mix up a quart and see how it goes.

 

[Doremus Scudder]

Unless you shoot and process regularly, you'll likely find it more economical to save film for processing till you have enough for a "batch" and then mix only enough fix for the batch you are processing. Saving fix is fine if it gets used before it ages out. Life of working-strength fixers in a half-full bottle is about one month. If you don't regularly use up a liter/month it may be better to mix the fix you need for the session and discard it afterward. Liquid-concentrate fixers allow you to do this.

Best,

Doremus

 

[ron917]

Thanks for your insight, Doremus. I can see the value in your suggestions.

I haven't been shooting much film because it costs so much to pay someone to process it. I'm hoping I will shoot more if I can process it myself at much lower cost. But that remains to be seen. Maybe I'll exhaust my first quart of fixer through usage before it ages out, maybe I won't. Regardless, I'll have more information about my own usage patterns for the next batch.

 

[ron917]

Just to close the loop on this...

I mixed up 1 quart of working fixer from the Kodafix liquid at 1 + 3 per the instructions. We will see how long it lasts, I'll do a clearing test each time I use it.

I developed a roll of of Tri-X today using HC-110 dilution E, 6:48 at 22C (warm day today). Looks like I got some usable negatives, but it's obvious that the shutter on my Argus C3 is very inconsistent - some frames look OK, but others are obviously very over or under exposed. Next time I'll use a camera with a known accurate shutter.

Thanks to APUG for my success today, I was able to find all of the info I needed in these forums!