Chemical quantities in 12x16 trays

Discussion in 'B&W: Film, Paper, Chemistry' started by FrankB, Nov 18, 2005.

  1. FrankB

    FrankB Member

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    I normally work in 8x10 but on the run up to Christmas I'm going to be making some 12x16 prints for my wall. Some of these are going to be toned in gold.

    As gold toner is just a bit pricey(!), do you think I can get away with using 1 litre of gold toner in a 12x16 tray if I keep it moving, or am I going to be forced to frighten the moths in my wallet again?

    Thanks in advance,

    Frank
     
  2. Kevin Caulfield

    Kevin Caulfield Subscriber

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    I think you can just about get away with it. I use 600ml of dev, etc. in 8 x 10, and triple it for 12 x 16, so that would be 1.8 l. One litre will be stretching it, but should be do-able.
     
  3. srs5694

    srs5694 Member

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    You might also consider buying a print drum, as are commonly used for developing color prints. They require much less liquid volume than trays. Of course, this won't get around any capacity issues with the toner, if that's an important factor.
     
  4. Monophoto

    Monophoto Member

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    There are two issues here. The first is whether there will be sufficient depth of chemical to cover the print. A liter of any liquid is a volume of 1000 cubit centimeters, or 61.0234 cubic inches. If that amount of chemical is placed in a 12x16 inch tray, the resulting depth will be 0.3174 inches if the tray is level. (If your trays are in a sink, the bottom of the sink may be sloped with the result that the trays aren't level. In that case, the depth of liquid won't be constant across the tray.) Therefore, there should be no difficulty in covering a 12x16 inch print with a liter of chemical in a 12x16 inch tray.

    Incidentally, when paper is taken out of the package, it has a slight curl (toward the emulsion). As dry paper starts to soak up developer, the curl initially increases, and then as the emulsion becomes soaked, it eventually flattens out. The time for this to occur varies between papers, but can be as long as 15-30 seconds. If you simply place the print in the developer with the emulsion side up, the edges will tend to rise out of the devloper during these first few seconds. If the development time is, say, 2 minutes, it is possible that it might be necessary to fight to get those edges to remain submersed in the developer for as much as 25% of the total development time, and this could result in a perceptable difference in image density along the edges. For this reason, I prefer to initially place the print in the developer face down so that the edges of the print come in contact with the developer during this initial "soak up" period, and then filp the print over to complete development with the emulstion side up. Obviously, this concern is greater when the liquid volume in the tray is small. Note, however, that once the print is wet, all that is necessary is that the liquid depth be enough to cover the print, so as a practical matter this concern is limited to developers.

    The second concern is whether the volume of chemical is sufficient to process the number of prints that you expect to produce in the session without exhaustion. In this case, you need to know the manufacturer's recommendation for the number of prints that can be processed in a given volume of his product. The data I have seen has been specified in one of two ways. Kodak used to specify usage rates in terms of the number of 8x10 prints that could be processed per unit of volume, while other manufacturer's have specified the total area (square inches, square meters, hectares, whatever) for a volume. You need to research the specifications for the materials you will be using, and then do the math.

    I suspect that manufacturer's specifications are conservative and that you could actually squeeze a few more prints through the process. Obviously, if you process sequentially, the earlier prints will have the benefit of fresh chemistry while the prints at the end of the run will be working against partially exhausted liquids and it is possible that the difference could be perceptable. One approach to addressing this is to increase the processing time as the chemical becomes exhausted, but that's a pretty experimental approach. Alternatively, you can compensate for this by processing all of the prints at the same time - but then you have to revisit the issue of the depth of the liquid in the tray and the fact that it can be a pain try to shuffle a bunch of prints in tray that is the same size as the prints you are processing.
     
  5. Carol

    Carol Member

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    Frank have you tried putting a litre of water in a 12x16 tray to see how shallow it is? I use 12x16's with 2 litres of chemicals for everything as that is all I have. I'd be a bit concerned a litre wouldn't be deep enough as when I've been low on chemicals and had to use less, the print is hard to manage, it sticks to the bottom. I don't know how expensive gold toner is, but it would be a shame to mess up something special you're working on. Good luck whatever you decide. :smile:
     
  6. Dave Miller

    Dave Miller Member

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    The answer is yes. Keep the toner swirling around the tray. I use Tetenal Gold Toner this way. Provided you keep a tray just for the toner and are very careful not to contaminate it, then it will last a longtime. I use times from 30 seconds to 10 minutes depending on the effect required. Bye the way, Arem sell the stuff for £15.00 a bottle, which is about £10 cheaper than anyone else.
     
  7. Dave Miller

    Dave Miller Member

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    Forgot to add, soak the paper first, and slide it under the toner just as you would when putting it in the developer.
    I must emphasise the clean bit. If you get the slightest trace of any other chemical in it; it's dead. So dedicate a tray, and equipment, and make sure your prints are very well washed prior to putting them in it.
    Other than that, enjoy the experiance.
     
  8. dancqu

    dancqu Member

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    I don't know which Gold Toner you have in mind
    but there is a good article at www.unblinkingeye.com
    where GP-1 is detailed. At 100 8 x 10s per gram Gold
    can't be all that pricey.

    As for volume of solution you may wish to conduct
    some dress-save-for-the-toner rehearsals.

    When agitating I for the most part move the print
    rather than the tray. The print is folded upon
    itself far to near then right to left. Twixt
    those moves I give the tray a bit of
    sliding to and fro, back and forth.

    Wet the paper first, empty, then add whatever.
    A solution volume of 250ml for an 8 x 10 is more
    than enough. With only a little practice I think
    you'll find 125ml very easy to work with. Dan
     
  9. FrankB

    FrankB Member

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    Many thanks for all the replies!

    Jay - Outstanding idea. Why the hell didn't I think of that?! :smile: I'll give it a shot, but it won't be for a little while yet.

    Monophoto - Many thanks for all the calculations. Like yours, my prints spend the first thirty seconds face down then are turned to reveal all their glory (ahem, yes well...! :rolleyes: ).

    Dave - Thank you. You mentioned the Tetenal brew at the Gathering. ATM, I'm using Fotospeed AU20 and it has quite a lot of life left in it. When it runs out I'll have a look round.

    Thanks again, one and all.

    Frank