"Combi-Plan" for 8x10

Discussion in 'Darkroom Equipment' started by Nick Kanellos, Jul 10, 2010.

  1. Nick Kanellos

    Nick Kanellos Subscriber

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    This comment on another thread garnered some interest. Instead of hijacking that thread, I thought I'd answer here.

    I made this tank a few years ago because I could never trust myself to develop my 8x10 negs in a tray. Not having the patience to tray develop one neg at a time I would invariably scratch them. So I took a good look at my combi-plan and made something similar for 8x10.

    The questions from the other thread were:

    Q: Is it all metal?
    A: No. It's 1/4 inch PVC sheet. It's actually the same material that my darkroom sink is made with. I drew up a schematic and had the local plastics shop cut the pieces. I assembled it myself using PVC cement.

    Q: Do I develop my sheets back to back?
    A: I will now! :smile:

    Some other Q's and A's:

    Q: how much did it cost.
    A: About $30 for all the parts.

    Q: How do you fill and drain?
    A: Using the fill and drain spout on the side. The spout is 3/4 inch PVC pipe cemented onto the side. I open the air vent on the lid when filling and draining to avoid "glug-glugging". It takes about 15 seconds to fill and drain.

    Q: How much liquid does it hold?
    A: 3.5 Liters. A bit much, but less than other tanks for hangers.

    Q: How do you load your film?
    A: I load it onto standard Kodak hangers and insert the hangers into slots at the top of the tank.

    Q: How do you agitate?
    A: Like my Combi-Plan, I grab the two ends and invert once to the left and once to the right. I invert around an axis perpendicular to the plane of the film.

    It's also great for stand development in daylight.

    Well, hope this answers the questions. Please feel free to post more if you're curious.
     

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  2. tim k

    tim k Member

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    If your inverting, what did you do for a gasket?
     
  3. Sirius Glass

    Sirius Glass Subscriber

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    Can I get a copy of the drawings so that I can scale it down to 4x5?

    Steve
     
  4. Nick Kanellos

    Nick Kanellos Subscriber

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    OOPS, forgot to mention the gasket. I got a small sheet of gasket material from here. I just fit it into the lid and cut a hole for the air vent.
     
  5. fschifano

    fschifano Member

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    Very cool. I like it. Simple, effective, looks to be durable, and inexpensive to boot. What more can one ask for? As for the amount of chemistry, it's not excessive if you're running 4 sheets of 8x10 film.
     
  6. tim k

    tim k Member

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    Very nice, I tried to build something similar for 4x5, but gave up and bought a combi-plan. Good job.
     
  7. jon.oman

    jon.oman Member

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    Very nice!

    Jon
     
  8. fotch

    fotch Member

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    Nick, when do you go in production? :D
     
  9. M.A.Longmore

    M.A.Longmore Subscriber

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    That's a thing of beauty !


    Ron

    From The Long Island Of New York, and the
    Long Island @ Large Format Group, right here on APUG
    .
     
  10. smieglitz

    smieglitz Member

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    That would make a nice silver nitrate sensitizing bath for wetplate collodion photography as well. Half the hassle of wetplate is filling, filtering, and dumping the silver tank after each location move. A gasketed, lockable tank like this would eliminate that hassle.

    You could sell these to the wetplate crowd easily.
     
  11. Nick Kanellos

    Nick Kanellos Subscriber

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    Steve, sorry, the drawings are long gone. In any case, I don't think they'd transfer to 4x5 since the hanger proportions are different. Looking at my 4x5 hangars, the top rail extends out much further than it does for 8x10.