Fixing: single vs double bath

[wiggywag]

How important is double bath fixing compared to a single bath?

I use only FB papers. I have a nice Archival washer, so my washing should be good :-)

[mts]

You can test the result of your fixing with a silver nitrate solution. Details are in Kodak publications. If the test shows fixing is complete, it does not matter whether you use one or two baths. Two baths are used mostly for production environments to obtain maximum life from the fixers before discarding. The second bath is discarded and the first one becomes the second bath with new fixer for the first one. Fixing is either complete or not so if your present method works there is no need to change it. If you are not re-using fixer you are unlikely to exhaust the one bath.

[Anscojohn]

How important is double bath fixing compared to a single bath?

I use only FB papers. I have a nice Archival washer, so my washing should be good :-)

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I won't know how archival my fb processing is for another 125 years or so. In the meantime I use the standard two-bath approach, with a third straight hypo bath before dilute selenium toner. So far, so good (ca 50 years).

[CuS]

The second bath is discarded and the first one becomes the second bath with new fixer for the first one.

should it actually be the other way around - discard the first and move up the second?

[Rich Ullsmith]

Yes.

[jeffreyg]

I also use a two bath technique. Kodak Rapid Fix with no hardener. I believe if you use an acid stop bath before fixing the first fixer will become quite acid by the end of your session. I follow fixing with Rapid Selenium Toner with some hypo clear and the hypo clear before washing. I've used this for over thirty years with no apparent change in the prints having used a variety of FB papers. I say if the prints are important to be made, go with archival process.

[wiggywag]

I also use a two bath technique. Kodak Rapid Fix with no hardener. I believe if you use an acid stop bath before fixing the first fixer will become quite acid by the end of your session. I follow fixing with Rapid Selenium Toner with some hypo clear and the hypo clear before washing. I've used this for over thirty years with no apparent change in the prints having used a variety of FB papers. I say if the prints are important to be made, go with archival process.

What stop bath do you recommend?

[timk]

i use 2 bath fixing for FB paper. It's good insurance against under-fixing and you do tend to get more mileage out of the fixer

[jeffreyg]

Kodak Indicator Stop Bath @ 16ml/liter

[nworth]

Two bath fixing has some advantages if you are doing a lot of printing. The method makes the most out of the fixer's capacity and assures adequate fixation throughout the session. You fix your prints for half the recommended time, with agitation, inthe first bath, then transfer them to the second bath for the remaining time. Most of the fixing happens in the first bath, which become loaded with silver complexes. After it is exhausted (Kodak says 200 8X10 prints per gallon, roughly 50 per liter), you discard the first bath, start start using the second bath as the first bath, and prepare a new second bath. Discard both baths after the equivalent of 1000 8X10 prints per gallon (250 per liter) have been fixed. If you only process 10 or 12 prints in a session and are not in the darkroom every day, the two bath method makes less sense. You would do better by mixing up a single fresh batch of fixer for each session.