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  1. #21
    JG Motamedi's Avatar
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    Quote Originally Posted by TheFlyingCamera
    I do know someone who has had glass plates burst into flame and shatter in his hands while coating... it happened when he was trying to keep a plate warm enough for the collodion to stay fluid while photographing in the field in Montana in the fall. He was coating it over a gas jet.
    This is a new one to me. Coating over a flame. Hmmm, not very smart. There would be better ways of keeping the collodion warm, like keeping the bottle in warm water. Anyhow, there are different recipes for summer and winter collodions; changing the ratio between ether and alcohol.

    But I have dragged the thread from from its origin. Sorry Wayne!

  2. #22

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    I have never prepared collodion, but I used to make nitrocellulose lacquer - which apparently is the same thing - by the ton. The solvents used for it are all highly flammable, yet I never used ether (too flammable, explosive and expensive). Is there any advantage of ether over the usual solvents for NC ? (ethyl acetate, butyl acetate and cellosolve). My only variations of the lacquer formulations were usually related to balancing solvents for a drying rate that would avoid whitening of the coating (due to water condensation in the film while drying).
    Photos are made four inches behind the camera

  3. #23
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    Different solvents are required for different nitration levels on the nitrocellulose spectrum. This was the original distinction between guncotton, collodion, and celluloid. The more nitration, the "hotter" solvent is needed. The ether-alcohol mix used for collodion will work with NC lacquer (which is collodion/celluloid), but there's enough celluloid in the mix that toluene, xylene, and the acetates you mention will work, with greater safety. Straight collodion won't dissolve in toluene (the strongest solvent normally used in NC lacquer), only in ether/alcohol (or nitroglycerine, but that's not really an improvement in safety, is it?).

    Why won't your tintypes ignite? Most likely because the plate conducts off enough heat to keep the collodion from reaching a self-sustaining reaction rate before you give up. Possibly also because the bitumen or asphaltum (or modern equivalent) used to japan the plate acts as what explosives chemists call a "phlegmatizer" and reduces the sensitivity and/or reaction rate of the collodion. Or just possibly the lacquer admixes with the collodion in some fashion that makes it act more like modern thermoplastics than collodion; if the lacquer is strongly endothermal it might prevent the reaction becoming self-sustaining.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  4. #24

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    Theoretically you can prepare cellulose mononitrate, cellulose dinitrate, and cellulose trinitrate. Practically when you react cellulose with nitric acid you get a mixture of at least two of the nitrates. The actual composition depending on the nitrating mixture and the length of time for the reaction. Collodion is primarily cellulose dinitrate. It is still sold to cover wounds.

    Glass for photographic plates may be slightly etched on one side with hydrofluoric acid. The etching is slight but provides a better tooth for the emulsion to bind to it. The plate may then be coated with egg white and dried before the collodion or gelatin emulsion is applied.

    Using hydrofluoric acid requires rubber gloves as it can cause serious burns which are slow to heal.

  5. #25

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    Quote Originally Posted by Gerald Koch

    Glass for photographic plates may be slightly etched on one side with hydrofluoric acid. The etching is slight but provides a better tooth for the emulsion to bind to it. The plate may then be coated with egg white and dried before the collodion or gelatin emulsion is applied.
    Ok, asking as a novice, will the gelatin stick to the plate by itself without using egg white (do you just use plain ol egg's?) and is there any tint to the gelatin. If using egg white does it impart a color? I'm leaning towards buying some photographic gelatin and trying it.

    On the topic of hydroflouric acid, I know it's sold thru various art and crafts stores. Does the roughened glass surface cause problems when printing?

  6. #26
    JG Motamedi's Avatar
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    Wayne,

    Before etching your plates with nasty acid, try the gelatin alone. As long as your plates are clean you shouldn't need to worry. I have never had a problem with collodion adhering to regular window-pane glass, and I know that gelatin is used as a sub, so I can't imagine that you would actually have a problem.

    Gelatin should not have a color cast. Albumen adds a very slight yellow color to collodion (I don't know about its affect on gelatin, but again, I don' think you need it). Albumen used as a sub is highly diluted, generally one egg white to 500 ml of water, whipped, allowed to settle, and then filtered.

  7. #27
    Ole
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    Strong alkali will also roughen the glass, which is why the old instructions call for washing the plates in strong ammonia. Nasty stuff, but nowhere near as nasty as hydrofluoric acid!
    -- Ole Tjugen, Luddite Elitist
    Norway

  8. #28

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    Quote Originally Posted by JG Motamedi
    John,

    jason

    ps: I think the "dangers" of collodion are overstated. Cutting glass is very easy as long as you spend the $20 on a good oil-type cutter (Toyo makes a great one). Also, the set-up isn't likely to blow up, since collodion is only dangerous at one stage of its production, and very few people make their own collodion; it is commercially available. Lastly, there is no reason to use potassium cyanide as a fixer, regular hypo works just fine.
    The glass is easy to get precut to size and simply polish the edges. I do both wet and dry plate collodion in 5 x 7 and 4 x 5 sizes. Have the glass precut at the local building supply outlet that also seels gals and polish the edges on a cheap belt sander.

    Collodion does use a lot of chemicals as almost everything ends up being mixed from scratch, but I don't know who if anybody makes their own collodion these days and that is where the real explosive risk comes in. A lot of other chemicals are hazardous all right, but not any more than most of us use doing alternative processes in general. Proper use and awareness of the nature and risks involved and there shouldn't be the issue it gets made. If a person can't take the time to learn to use the chemicals proper, there's always digital!

    I've found using collodion dry plates really makes collodion full of endless possibilities as you can do collodion photography any where and under basically any weather condition, and not be stuck having to have all the regular chemical, a dark box or dark tent hauled everywhere -- just a camera, a light tight box for the plates, and a changing bag. Develop later at home in the darkroom.

    The old Silver Sunbeam available on line has some good formulas and instruction for collodion dry plates. http://albumen.stanford.edu/library/...am/chap37.html

    Here's a URL for a good run down on using liquid light for glass plates, much faster and easier than collodion dry plates. http://www.alternativephotography.co..._dryplate.html

    As always;

    J Truman

  9. #29

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    Here is a link to the Wet Plate Collodion forum via JT Szabo's web site:http://www.cwreenactors.com/collodion/

    I am pretty sure that guys like Szabo, John Coffer, and the Ostermans who really started the revival in wet plate through photographing Civil War re-enactments mix their own collodion from scratch.

    Both Coffer and Osterman have manuals about wet plate but I don't know if you can just buy them or you need to attend a workshop to get them. These guys are a pretty clubby group and I think they derive a good amount of income from the workshops. From what I gather the workshops are excellent and well worth the cost and effort to attend.
    "Fundamentally I think we need to rediscover a non-ironic world"
    Robert Adams

  10. #30

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    they used to also suggest washing the side of the plate you want to coat in strong stop bath. i never did this, just laundry detergent and then lighter fluid, then see if the water "sheets off" the glass, then just plain old non-flavored jello (knox) gelatin. i never used albumen first, and never really had troubles to speak of. it is really pretty simple wayne
    it only sounds hard because of the cleaning of the glass, but it is a lot easier than it sounds.
    if you are in the hot florida sun, you might want to add hardener to the gelatin + later, the emulsion. i have read about extreme heat (re)liquifying either the gelatine or emulsion. up here in new england it gets king of hot, but not *that* hot.

    - john

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