Single-use fixer approach

PhilippReichmuth · 2005-07-09T17:41:28+00:00

Hallo, wie genau muss ich die Dosierung beim Ansatz von Einmalfixierbädern ansetzen? Meine erste Idee wäre (Gesamtmenge Konzentrat / Gesamtkapazität) * An...

PhilippReichmuth

Hello, How exactly should I calculate the dosage when preparing single-use fixing baths? My first thought would be to use

(Gesamtmenge Konzentrat / Gesamtkapazität) * Anzahl zu fixierender Filme

and then perform dilution to the required volume of liquid, followed by fixing for the standard time. With Adofix, for example, that would be about 12 ml of concentrate per film. Is that about right, or am I completely off track? I thought I’d better ask before I ruin my films... :rolleyes: Philipp

andreasbrigachtal

Hi Philipp What’s a single-use fixer? :rolleyes: I use my fixers until they’re finished. You can keep track of this by counting the number of films you’ve fixed, or by measuring the silver content! I also always use a two-bath fixing process. Bath 1 is recycled with a silver content of 3g, and bath 2 is added to bath 1. You can read about this in great detail in the black-and-white section of Mr Wollenstein’s magazine. As I understand it, I would advise against using a fixer as a single-bath process. However, I’m always happy to be proven wrong! Happy shooting Andreas

rherz

Hi Philipp, I use my fixer as a single-use fixer. It’s not the most economical solution, but it’s the most convenient. So, prepare the fixer to the highest dilution specified, determine the settling time, calculate the development time (classic films x 2, flat-crystal films x 3) and that’s it. It works quite well, and the fixer is always fresh and the fixing times are consistent. Best regards, Robert

PhilippReichmuth

Hi everyone,

what is a one-step fixer?

Well, here’s the situation: I have a rotary processor here that’s just being put back into service, a Mafina V50. The machine develops four 120-format or three 135-format films in 600ml of chemical solution and then tips the solution away. If I want to reuse the chemicals, I place buckets underneath, which I then swap out during the process. I’m a forgetful sort, and then the machine just tips everything out together. That’s why I want to use single-use chemicals, place a large bucket underneath and then dispose of the whole lot together. Single-use developer isn’t an issue. Now I’m wondering how to prepare 600 ml of fixer for a single use to fix four films, and what concentration I should use. If, like Robert, I use the lowest specified concentration, I’m wasting some capacity. I’ve just done the maths again, though, and it’s not a big deal. If I prepare Adofix at 1:9, a litre of stock solution (10 films) costs about 55 cents. If I then use 600 ml for four films, that’s less than ten cents per film that I’m wasting. I can live with that quite well. I’d initially calculated using other fixers, but that would be more expensive. I’d still be grateful for a few general pointers on how fixing and fixing capacity depend on the fixer concentration. Can I carry out further dilution of the fixer if I need less capacity, or does it eventually stop fixing altogether?