Stretching Fixer.

Discussion in 'B&W: Film, Paper, Chemistry' started by lightwisps, Jun 24, 2013.

  1. lightwisps

    lightwisps Subscriber

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    I have made a big boo-boo. I thought I had an extra bottle of Ilford Fixer. I was wrong. I want to make an 11X14 but only have enough fixer to do a fair job of filling an 8X10 tray. Can I add a bit of water or will that dilute it to much to be usable. Any other tricks anyone knows of will be appreciated. Thanks, Don
     
  2. Kevin Kehler

    Kevin Kehler Member

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    You can dilute it more but then it needs to be in the fixer longer. If you add 25% more water (go from 4 liters to 5 liters), I would add 25% more time to the fix cycle and 50% more time to the wash cycle. If the paper is RC, it is not too bad but fiber paper, the longer it is in the fixer, the more it is absorbed into the paper and the greater chance of archival instability. Be sure to recalculate how much life expectancy you have as 5 liters of diluted fixer will not properly fix the same amount as 5 liters of non-diluted fixer.

    If you have a rotary drum, you could use that for fixing the print and it would require less fixer.
     
  3. MattKing

    MattKing Subscriber

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    Do you have any Beseler or Cibachrome developing tubes big enough for an 11 x 14?

    You can also use an 8 x 10 tray, and the same technique as mural printers use to develop large sheets - roll develop the print.
     
  4. lightwisps

    lightwisps Subscriber

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    Yes, I do have Ilfochrome tubes that are that large and even larger. Largest Ilfochrome I can make is 20X24.

    Thanks guys, great ideas, Don
     
  5. clayne

    clayne Member

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    Why wouldn't one be able to use a tray to achieve the same approach as a drum with less chemicals? It's not as if the surface has to be round to get liquid coverage across everything - it just won't be covered entirely at once. That doesn't seem any different than a drum.
     
  6. tkamiya

    tkamiya Member

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    I've tried this. If the chemical is *just* enough for 8x10 tray, it will be very VERY difficult to make sure all the paper surface is covered. Sloshing it around is pretty risky as one won't know if the whole surface is sufficiently fixed until it's way too late.

    I wouldn't do it. If I had to, I'd rather dilute what's available more and chance it.
     
  7. clayne

    clayne Member

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    I think it's because most trays have the gutters on the bottom. If using a flat tray (which most of us don't) it'd probably work out fine.
     
  8. Clovis Blevins

    Clovis Blevins Member

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    I think fixing silver bromide in excess sodium thiosulfate may reasonably be assumed to be a pseudo first order reaction. The concentration of unfixed silver at time (t) would = initial concentration of silver times e to the power of (-k times concentration of thiosulfate times t). So half the concentration of fixer means double the fixing time. Well, close enough, anyway.
     
  9. lightwisps

    lightwisps Subscriber

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    Good point. I really appreciate the help. I must have really had my head up where the sun don't shine to screw up this badly. Real problem is I can't blame anyone but me for this jolly bit of stupidity.
     
  10. Rudeofus

    Rudeofus Subscriber

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    Do you have any data to back this up? From what I know, fixation is anything but a first order reaction, see here, especially pages 3 and 4.
     
  11. jeffreyg

    jeffreyg Subscriber

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    Personally, I use two fixer baths but if the 11x14 print is important why not wait to print it when more fixer is available. In the meantime make a good 8x10 or at least an 8x10 work print.

    http://www.jeffreyglasser.com/
     
  12. NB23

    NB23 Member

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    1:9 + one extra minute will be plenty enough! Especially in freshly mixed fixer.

    Absolutely no worries!
     
  13. Clovis Blevins

    Clovis Blevins Member

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    A pseudo first order reaction is not a first order reaction. It just proceeds at nearly the same rate when one reactant is in large quantities compared to the other reactant and you don't have lots of reaction products forcing equilibrium in the opposite direction. The example you gave does not fit this model because fixer near exhaustion has a lower concentration of thiosulfate (reactant) and a significant concentration of reaction products.

    This is just a simplification using conditions present with fresh unused fixer so that real people who don't know how to solve second order differential equations and don't have an analytical chemistry lab to measure precise starting solution concentrations can come somewhat close. You can make it as complicated or as simple as you wish. But don't take my word for it. Clock your clearing time in fresh fixer then dilute it 1:1 and see if twice the fixing time clears your clip.
     
  14. Chris Lange

    Chris Lange Member

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    Honestly, I don't even bother producing final prints without two fixing baths, both of which are known quantities, both in volume, and usage capacity. If I am making prints for exhibition or portfolio purposes, I use two trays of film strength rapid fixer, for 45 seconds each. The first fix is discarded or put away for disposal after 3 work sessions, and the second tray becomes the first fix for the following 3 sessions, with a brand new batch of film-strength fix being made to replace it. I find with this method that I get complete, archival fixation, with very little thiosulfate actually absorbing into the fibers of the paper, meaning that I only have to do a quick rinse, a three minute soak in Permawash, Selenium toning, and then a 30 minute wash in my print washer, which is a SaltHill cross-current washer with the quick dump panel. Every 10 minutes, I dump the balance of the water in the washer, and let it refill with totally fresh water. So three or four changes of water over the course of 30-45 minutes.

    The longer the print is in fixer, especially previously used fixer, the more residual silver will seep back into the print as the paper must remain immersed for a greater amount of time. You really don't want to have your prints in fix for a combined time greater than 2-3 minutes at the most. A minute to a minute and a half is preferable.
     
  15. StoneNYC

    StoneNYC Subscriber

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    Does this effect of silver seeping into paper also happen with film emulsion? Will you actually fog film if you over-fix it?


    ~Stone | Sent w/ iPhone using Tapatalk
     
  16. Chris Lange

    Chris Lange Member

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    I suppose theoretically it could, but it I would think it is far more difficult to achieve / far less likely to happen. As you know, film and RC papers have only a shade of the absorption capacity that baryta and rag papers do, and even then they wash far more easily due to the non-porous nature of the materials. Everything I said above applies basically exclusively to FB or Cotton papers like ART300.