Substitute for Edwal No-Scratch - Glycerine?

Discussion in 'B&W: Film, Paper, Chemistry' started by Smudger, Dec 21, 2007.

  1. Smudger

    Smudger Member

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    Sooner or later I'm going to run out of this stuff,which is unobtainable now in this part of the world.
    I've tried Glycerine,but it is too viscous.
    Could someone suggest a suitable dilutant ?
    I need something a little more heavy-duty than noseoil..
     
  2. PHOTOTONE

    PHOTOTONE Member

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    I think Edwal NoScratch has turpentine in it. You could try that. Its oily, but cleans off well with film cleaner.
     
  3. Snapshot

    Snapshot Member

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    Nose skin oil (yes, really) will be a good replacement. It has approximately the same refraction value as film.
     
  4. jim appleyard

    jim appleyard Member

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    Yes, nose oil does work and so does turpentine, a componant of No Scratch.
     
  5. jim appleyard

    jim appleyard Member

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    Glycerine is water soluble. Perhaps if you thinned it a bit?
     
  6. PHOTOTONE

    PHOTOTONE Member

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    You don't want to use anything that has water in it, as this will cause the emulsion to swell and become fragile. Your best bet is to use a petroleum based product, turpentine, if you can't get No Scratch.

    Any type of light mineral oil type substance should work to temporarily fill in the scratches, and then can be removed with film cleaner, which is a solvent that removes oils.
     
  7. gainer

    gainer Subscriber

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    Propylene glycol is thinner and might work alone. It certainly can be used to dilute glycerine.

    I don't think just anything can be used. The index of refraction must match the film base pretty well.
     
  8. Photo Engineer

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    I don't think I would suggest turpentine. It tends to get sticky with age. Glycerine sounds better, but nose oil is best.

    We used it at EK. Of course, just being a Kodak suggestion might disqualify it to many of you. :wink: My first boss had an imposing nose, source of much oil used on negatives at EK. He liberally spread it around when needed. He was head of the Negative, Positive Color Development Lab.

    PE
     
  9. George Collier

    George Collier Member

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    One more vote for nose oil. Clean it off right away with film clean.
     
  10. PHOTOTONE

    PHOTOTONE Member

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  11. gainer

    gainer Subscriber

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    We need to devise a special diet for photographers that will promote the production of nose oil.

    I think it was the people who made Omega enlargers who had an oil immersion negative transport for 35 mm photographers who have the most problems with these fine scratches. I wonder if they sold nose oil to go with it.
     
  12. Neal

    Neal Subscriber

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    Dear Smudger,

    Consider trying scanning fluid. Watch the flammability though when comparing brands.

    Neal Wydra
     
  13. jim appleyard

    jim appleyard Member

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    Or turn-signal fluid?
     
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  15. jim appleyard

    jim appleyard Member

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    Do you know of someone with this many scratched negs?
     
  16. Photo Engineer

    Photo Engineer Subscriber

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    The alternative oil to use is a type of silicone oil which does not evaporate and form a skin like turpentine. This is used in all wet gate printing.

    PE
     
  17. gainer

    gainer Subscriber

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    It could happen if its due to a scratch on the film path and you run 3 or more 36ers through before you find it. Reminds me for some reason of the "Dont you just hate it when..." skits I used to see on Saturday Night Live.
     
  18. Dave Krueger

    Dave Krueger Member

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    Luckily I have some reagent grade nose oil... :D
     
  19. AgX

    AgX Member

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    One should distinguish between scratches

    -) on the emulsion side
    -) on the base side

    (In case the base has a dulling layer refer to the first case. Antistatic surfaces on the base should be of no interest I assume.)

    The refractory index of gelatin is said to be 1.51 (with listings going from 1.465 to 1.550)
    A coating of some thickness (with the same ref.index as gelatin) on the emulsion side could reduce contrast but could also make image details visible again.

    (Tri-) Acetate has a refractory index of 1.48

    Polyester of 1.64


    a) Coatings in order to fill the scratches:

    Glycerine has a refractory index dependend on the amount of water absorbed covering the range given above.

    Tetrachlorethylene: 1.50 (very volatile though)

    A mixture of 9 parts Toluol an 1 part 1,1,2 Trichloro-1,2,2-Trifluoro-Ethane: 1.50

    Oil of cloves*l: 1.55

    Chinoline: 1.628

    Monochlornaphtaline: 1.633

    Monobromenaphtaline*: 1.656

    *could be mixed too

    (the tolerance between emulsion or base and the coating should be within 0.02 .


    b) Coatings just to give a dulle surface in order to countereact the refractory effect,

    c) dulling by another means,

    d) Smoothening the gelatin, and thus the scratches, by repeated swelling and drying


    I got all these ideas from a publication of our fellow member Gigabitfilm, who once made a factor-1000 enlargement of a pictorial negative and thus looked into film-surface problems.
     
    Last edited by a moderator: Dec 22, 2007
  20. Photo Engineer

    Photo Engineer Subscriber

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    Quinoline (Chinoline in German), Monochloronapthaline and Monobromonapthalene are all quite nasty. I would avoid them at all costs. The other mixtures or chemicals such as tetrachloro ehtylene and the Toluol are not much better and the Toluol is quite flammable. The latter two are volatile.

    No, you need a non-volatile liquid that does not absorb moisture. Nose oil, glycerine and silicone oils will fill those requirements and are also relative to the ones mentioned above, non-toxic.

    PE
     
  21. AgX

    AgX Member

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    To be fair to Gigabitfilm, he also referred to a silicone oil “Refrectasil” from the USA from 50 years ago with an refractive index of 1.46. But as I do not know whether this is still about, and for the rest silicone oils are not standardized I did not refer to silicone oils.
     
  22. Smudger

    Smudger Member

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    Turpentine,et al..

    Blimey- such a wealth of information ; my thanks to all.
    If I go the turpentine route, I assume Artists Distilled Turpentine would be preferable to the paint store variety??
     
  23. Photo Engineer

    Photo Engineer Subscriber

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    I would not do it. Turps dries into a filmy scum.

    Put some on a shiny surface and let it set for a few days. It will form something that is akin to tree sap. Well, thats what it is, really.

    PE
     
  24. gainer

    gainer Subscriber

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    I don't remember seeing a scratch in the emulsion that could be cured by nose oil or equivalent. Scratches in 35 mm are usually caused by the pressure plate. Zeiss, I believe, had a camera in which the pressure plate was lifted during transport. Leitz film cartridges for the early Leicas had no felt lips, but a gate that was opened after the back was closed. I had one of those once upon a time. It worked on an early Canon RF I had.
     
  25. Stephen Frizza

    Stephen Frizza Member

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    all the past pro labs Ive worked in have hidden scratches of that nature with nose oil its a tried and true method, just make sure to wash the negative after its printed.
     
  26. boyooso

    boyooso Member

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    silicone oil works very well. There are different viscosities to the oil... I want to say to the product is called silicone 200, but I can't remember if the 200 is the viscosity or the product.

    If you email me at prints (at) hiddenlightllc.com I can verify it for you.

    But nose grease works in most cases for sure!

    Good Luck,

    Corey