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  1. #11
    JG Motamedi's Avatar
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    I wish I had more uses for the word (or even the concept), but I am afraid that I am too deeply entrenched...

    jason

    ps: Pool supply stores can be a good source of very cheap hypo.

  2. #12
    Kerik's Avatar
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    Quote Originally Posted by Donald Qualls
    I think you're deeply confused -- possibly dangerously so, Kerik.
    Donald, thanks for your 'concern', but I'm not confused. You are simply ignorant of my working practices. Maybe you could have asked before you started talking out of your behind.

    I'm aware of all the hazards of working with HCN that you describe. In my day job, I've been trained in the use of PPE for handling hazardous materials. When I'm working mobile (out of my camper darkroom), I fix outside. In my home darkroom I fix in front of a 400 CFM exhaust fan and wear a respirator. The 200 ml of 1.5% HCN solution is in the tray for a total of 20 seconds, then it's back in the plastic storage bottle. And, I know full well that the plate has to be completely rinsed of the acidic developer prior to fixing. hmm-K?
    Kerik Kouklis
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  3. #13
    colrehogan's Avatar
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    Nice image, Joe. Was this the effect you were looking for? Sorry I'm not familiar enough with the process to even attempt to answer your question regarding the chemistry. I'm still trying to learn about it myself.
    Diane

    Halak 41

  4. #14
    smieglitz's Avatar
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    Quote Originally Posted by colrehogan
    Nice image, Joe. Was this the effect you were looking for?...
    Diane,

    I ran into problems with fogging the other day that I thought were related to the sensitizer and developer being at very dissimilar pH values. The attachment shows the difference between the test plate of the mannequin after I adjusted the pH and a detail of a portrait from earlier last week. Both were done on black glass with the same light, and lens.

    The gray veiling that is evident on the portrait is what I was trying to get rid of. The mannequin shot from yesterday has much better contrast and is also warmer, both effects which are desirable. The mannequin image had the sensitizer and developer at roughly the same pH and I used an ammonium thiosulphate-based fixer on that plate for the first time. It cleared and reversed the image in about 15-20 seconds which was much quicker than plain hypo and in about the same time as the KCN would act.

    So, the test plate chemistry changes did what I was hoping.

    Joe
    Attached Thumbnails Attached Thumbnails Maureen_02_crop.jpg  

  5. #15

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    Quote Originally Posted by Kerik
    Donald, thanks for your 'concern', but I'm not confused. You are simply ignorant of my working practices. Maybe you could have asked before you started talking out of your behind.

    I'm aware of all the hazards of working with HCN that you describe. In my day job, I've been trained in the use of PPE for handling hazardous materials. When I'm working mobile (out of my camper darkroom), I fix outside. In my home darkroom I fix in front of a 400 CFM exhaust fan and wear a respirator. The 200 ml of 1.5% HCN solution is in the tray for a total of 20 seconds, then it's back in the plastic storage bottle. And, I know full well that the plate has to be completely rinsed of the acidic developer prior to fixing. hmm-K?
    The problem is in your nomenclature Kerik. Hydrogen Cyanide is a gas at room temperature and it is fatal at low concentrations. You are using Cyanide salts, which if kept away from strong acids are perfectly safe to handle if you use the appropiate precautions.

    While you might think this is nitpicking, I think this is one instance where the right information and nomenclature are used. After all we dont want people trying to make Hydrogen Cyanide to fix their wet plates......

  6. #16
    Kerik's Avatar
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    Jorge,

    D'oh!!!! Thanks for pointing out my error. I now see that I made a typo in my first post, then it got perpetuated. I use POTASSIUM cyanide (KCN), NOT hydrogen cyanide (HCN). I should have spelled it out rather than fat-fingering the abbreviation. So, Donald, perhaps that's what you meant by being confused. I'm not confused, but I am a crappy typist.

    In any case, I suppose I should emphasize that no-one should delve into processes like wet plate, daguerrotype or anything involving dichromates without understanding the hazards and proper handling of these materials. I apologize for any confusion I may have induced.
    Kerik Kouklis
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  7. #17
    Kerik's Avatar
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    Quote Originally Posted by smieglitz
    So, the test plate chemistry changes did what I was hoping.
    Joe,
    Do you think it was the pH adjustments or the change in fixer that resolved your problem? I went through serious fogging and veiling issues in the fall, as you probably recall from Quinn's forum. I started making plates again this week and everything is working very well (probably just jinxed myself by saying that). No fogging and very clean plates - no oysters or other funkiness happening.
    Kerik Kouklis
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  8. #18
    colrehogan's Avatar
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    Glad you got it sorted out, Joe.
    Diane

    Halak 41

  9. #19
    smieglitz's Avatar
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    Quote Originally Posted by Kerik
    Joe,
    Do you think it was the pH adjustments or the change in fixer that resolved your problem?...
    Kerik,

    I think it was the pH adjustment that caused the improvement. The plates appear warmer than before and that might be a result of the fixer change, but I'm not sure as the silver tank and developer also were changed at the same time.

    I think the oyster problem is obviously related to the cleanliness of the plate but I also think using whiting gets some of it into the silver bath and raises the pH of that solution. I can never seem to get all the whiting off the edges of the plate and if I mess with it enough to do so, I usually end up touching the clean surface of the plate which means I have to reclean it with whiting which sticks in the edges of the glass and gets into the silver bath...

    So, I'm hoping a diffent cleaning routine along with the pH changes will alleviate most of the problems I've been having with the plates. The Rapid Fixer is just more convenient and quicker, but if it is also warmer, that would be a welcome benefit.

    The best plates I ever produced were done dripping nitric acid and potassium nitrate into the developer so I think the lower pH really does help produce more fog- or veil-free plates.

    Plese refresh my memory as to how you alleviated the fog problem you had.

    Joe

  10. #20
    Kerik's Avatar
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    Quote Originally Posted by smieglitz
    So, I'm hoping a diffent cleaning routine along with the pH changes will alleviate most of the problems I've been having with the plates. The Rapid Fixer is just more convenient and quicker, but if it is also warmer, that would be a welcome benefit.

    The best plates I ever produced were done dripping nitric acid and potassium nitrate into the developer so I think the lower pH really does help produce more fog- or veil-free plates.

    Plese refresh my memory as to how you alleviated the fog problem you had.

    Joe
    Joe,
    I've only used Rottenstone for cleaning, and it seems to work well and residue is easily removed. I got it from a local boutique woodworkers shop. I'm 90% sure after many tests that I had either a contaminated or erroneously labeled can of EE.
    Kerik Kouklis
    Platinum/Gum/Collodion
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