how do you get liquid light to coat evenly?

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by zrh21, Apr 1, 2011.

  1. zrh21

    zrh21 Member

    Messages:
    5
    Joined:
    Apr 1, 2011
    Shooter:
    35mm
    I have a plate of glass thats about 8X10 and I entend to print an image on it useing liquid light. I used polyurathine as a subber (spray can of polyurathine) since I am limited in resources. The spray can seems to coat more evenly then applying the liquid version. After that I apply the liquid light, now I have tried a screen, useing a Lowes card, and just poring the liquid on the glass in a tray and with agitation, it still dosen't seem to coat evenly. Whatever way I get it applied, I let it dry (in a lightsafe box in darkroom). When its dry I use an ortho negitive and use the method of contact printing. The image is ethier to light or way to dark and since Its not coated evenly the emultion seems to come off in developer or fixer. I am just useing D76-dveloper one-to one and just a little bit of fixer which is applied only for a brief time then poured out. This is my first project with liquid light and i curtinly want to expirament with it in the future. If anyone has any Idea as to what I am doing wrong please let me know. Thanks:smile: I also am sorry for my spelling.
     
  2. jnanian

    jnanian Advertiser

    Messages:
    19,116
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    i use a haki brush and paint the emulsion on, and for years i used a foamy paint brush, and it worked just fine.
    i never used urethane because it yellows in time instead i use store-bought gelatin for a binder.
    sometimes more than one coat of the emulsion works best.
    look on alternativephotography.com under dry plates
    and also look for the book - silver gelatin, they are both great resources.

    good luck !
    john
     
  3. zrh21

    zrh21 Member

    Messages:
    5
    Joined:
    Apr 1, 2011
    Shooter:
    35mm
    type of liquid emultion

    what kind of liquid emultion do you prefer? thinks
     
  4. jnanian

    jnanian Advertiser

    Messages:
    19,116
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    i have only used liquid light ( rockland colloid ) i am sure others are similar ...
     
  5. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    hand pouring

    Cleaning glass is with Calcium Carbonate and EverClear which is a 155 proof vodka. I use a paint brush and scrub the glass and alcohol mix. After a warm tap water rinse the glass is sprayed with the Everclear and wiped with a paper towel while it sits on a rubber mat.
    My 4x5 plates take 15ml of Liquid Light so an 8x10 would need 60 but I'd have more so 75ml at least. I like to hand pour and thick. Temperature is 100 degrees F or a little less. It is carefully placed onto a marble slab that is warm on one end and cold on the other, just a little warm, it helps the emulsion to even out if it got too cold. 30 sec and it is slid to the cold end. It takes a few days to dry. It sticks all the way to the edges and never comes off.
    Dektol 1:3 develops in about 2 min. Fixing can take a long time, I use a black tray and inspect it after something starts to happen.
    I've been coating with Formazo lately and just started using a puddle pusher and glass edge pieces. It was actually easier than hand pouring.
     
  6. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    Last edited by a moderator: Apr 4, 2011
  7. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,102
    Joined:
    Apr 19, 2005
    Location:
    Rochester, N
    Shooter:
    Multi Format
    I have posted pictures here made by Mark Osterman of George Eastman House. He gave me the series as a demo on how to coat glass plates for use of the APUG members wanting to do this. I also recommend the use of a small amount of alcohol (everclear) to assist in even spreading, or the use of a surfactant to help even spreading. Chrome Alum is recommended as a hardener to assist in making the gelatin adhere to the glass.

    PE
     
  8. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    My efforts at hand pouring plates in the air didn't result in acceptable plates until I used a warm leveling stone. Revisiting that first hand pouring technique may result in better plates. There are questions I have about it. I bet the room was hot. My darkroom is in the cellar and cold. His plates may have already been warm, mine were not pre-warmed at first. The tea pot was dry in the photo so a warm cabinet may have been used, also, several pots could have been used. My method was to use a water bath to heat emulsion in a film canister. I wonder how emulsion was warmed 130 years ago. What temperature is best to have emulsion at? I'd settled on 100. Is Everclear and a surfactant the same thing? I'd tried a couple times to spray the glass once with Everclear then pour and that wasn't so good; perhaps on a larger sheet. Black Magic directions told to add the alcohol into the emulsion at some dilute proportion. There is a lot for me to work on to achieve acceptable flat even fully coated plates. I tried to keep as much emulsion on the plate as I could late in my first experiments and the photos show it being dumped back into the pot, making a thin layer.
     
  9. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,102
    Joined:
    Apr 19, 2005
    Location:
    Rochester, N
    Shooter:
    Multi Format
    Pouring emulsion on glass is an art. I had it dripping from my elbow the first time I tried, and Mark was trying hard to stop laughing. You pour at between 100 and 110 deg F onto a slightly warm plate, say 75 F. The room we have coated in varied from 68 to 75 deg F. The emulsion was kept warm in a warm water bath but not hot. Heating causes increased fog.

    Alcohol is a spreading aid and decreases bubbles but is not a surfactant. A surfactant would be Photo Flo 200 or Foma Flo, or something like that. They usually contain propylene glycol and polymeric ethers. They are usually nonionic or have negative charged Sulfonic acid groups on them, and so they are usually sold as Sodium salts of the ionic material.

    PE
     
  10. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    So, you put alcohol into emulsion and you put Photo Flo onto emulsion?

    MAC
     
  11. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,102
    Joined:
    Apr 19, 2005
    Location:
    Rochester, N
    Shooter:
    Multi Format
    You can use either or both, whichever one or combination gives good spreading on the plate. It differs with emulsion and plate cleanliness (cleaner used I suspect) and also with the hardener used. Mark uses Everclear and Chrome Alum hardener, I use Glyoxal and Photo Flo 200, but then I preharden during processing with Chrome Alum.

    PE
     
  12. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    Let me get this right, you are saying that either one may be put into the emulsion, then poured?
     
  13. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,102
    Joined:
    Apr 19, 2005
    Location:
    Rochester, N
    Shooter:
    Multi Format
    Either one or BOTH of them may be used as long as you get the desired effect. So, you can add Everclear (Ethanol) or Photo Flo 200 or both of them to your emulsion just before you coat.

    PE
     
  14. zrh21

    zrh21 Member

    Messages:
    5
    Joined:
    Apr 1, 2011
    Shooter:
    35mm
    Can the liquid emultion be applied under a red light or dose it have to be in the complete darkness? Thanks for all you help. Your images are awesome.
     
  15. studiocarter

    studiocarter Member

    Messages:
    185
    Joined:
    Dec 19, 2008
    Location:
    Pittsburgh
    Shooter:
    ULarge Format
    Red or dark orange are both in my studio. One is enough. It does not need to be totally dark. Instructions for Black Magic say to make a fog test; expose a plate to your safe light in 30 min incriments or something like that and then develop and see if you got any fog.