Shutter blades cleaning instruction

Discussion in 'Camera Building, Repairs & Modification' started by SalveSlog, Feb 8, 2018.

  1. SalveSlog

    SalveSlog Subscriber

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    I read in INSTRUCTIONS FOR REPAIRING PRONTOR-PHOTOGRAPHIC SHUTTERS at sheet(/page) No. 14:

    "Remove shutter blades from shutter, place blades on PLANE surface and wipe with a DRY cloth. Be sure to avoid fingerprints on shutter blades, as perspiration will destroy protective finish and thus give rise to rust formation."

    "wipe with a DRY cloth.." and "protective finish" makes me a little worried. Any comments, anyone?
     
  2. E. von Hoegh

    E. von Hoegh Member

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    Some blades are coated with a protectant, lacquer, perhaps. A solvent (moistened cloth) might remove this, leaving the blades more susceptible to rust.
    Also, it's a good plan to degauss the blades, a wee bit of magnetic attraction between the blades can slow the higher speeds by a stop, easily.
     
  3. shutterfinger

    shutterfinger Subscriber

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    The shutter blades I've encountered in Prontor shutters are .002 inch steel with a blue coating like firearms. It will wash off with some solvents which will require them to be reblued. Search engine Metal Bluing
    90% alcohol is safe to use on them provided you use it no warmer than room temperature.
    Rub with a cotton swab dipped in the alcohol. Coat the blades with extra fine powdered graphite or Teflon dry lube after cleaning.
     
  4. AgX

    AgX Member

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    Good idea.

    (Though I must be quite imaginative to think of ways how they could have got magnetized.)
     
  5. BrianShaw

    BrianShaw Member

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    Hi... would you please expound... bluing can be either chemical blued (as on firearms) or heat-blued (as on watch hands). Which technique is used on shutter blades? I, personally, have never experienced either to wash off by chemicals. I know hot-blue is more enduring than the cold-blue techniques used to "re-blue" or touch up wear marks on firearms, but still thought that both were quite safe from being washed off except by abrasion. Certainly by abrasion but not by chemical flush or ultrasonic agitation. What chemicals do you know that washes off either chemical or heat bluing? I certainly interested to learn something new!
     
  6. AgX

    AgX Member

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    In general blueing steel may have two aims:

    -) reducing hardening again (can only be achieved thermically)
    -) giving some anti-corrosive coating (thermically or chemically)
     
  7. E. von Hoegh

    E. von Hoegh Member

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    Me too, but I have seen it. Also with watches, I've found magnetised parts in watches I use, for no apparent reason.
     
  8. E. von Hoegh

    E. von Hoegh Member

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    I'm pretty sure most of the blue colored shutter blades are blued thermally (think blue tempered spring or shim stock) and then sometimes coated. I can't imagine them being hot blued as guns would be. The only common substance I know of that removes the blue coloring (from whichever method) is muriatic acid, and I'm pretty sure that it isn't a common cleaning agent.
     
  9. ic-racer

    ic-racer Member

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    Just don't mess with them using sweaty fingers. I use fine pickups to hold them and move them around. Frequently, if I'm at the point where the blades are free in a repair, a stray fingerprint is the least of my worries. That is, the less manipulations of the blades, the better.
    flipping shutter blades.jpg
     
  10. E. von Hoegh

    E. von Hoegh Member

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    A good basic rule is "Don't handle anything with your fingers".
     
  11. shutterfinger

    shutterfinger Subscriber

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    I haven't a clue which process was used when the blades were made. I've had bluing come off or weaken in hot alcohol and lacquer thinner will definitely take the bluing off. I use cold chemical bluing when rebluing is needed on the shutters I work on. A dry finger print can be rubbed off with a cotton swab.
    It is best to handle shutter blades with tweezers. Kinks/bends in the blades can be rubbed out by laying the blade on a hard flat surface and rubbing with the rounded end of a plastic screwdriver handle or similar then flip the blade over and repeat the rubbing.
    It may not be possible to remove all the kink/bend but it can be brought back flat enough that it will pass the other blades in operation and be light tight in the closed position. I have encountered kinked edges on shutters that have never been opened before.
     
  12. OP
    OP
    SalveSlog

    SalveSlog Subscriber

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    shutterfinger,
    could you actually see blue on the cotton/paper?
     
  13. shutterfinger

    shutterfinger Subscriber

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    I wash the blades in the ultrasonic cleaner, previously in a wide mouth jar with solvent. It washes off and looks black in solution or sludge that settles.
    The bluish color does not occur until the metal has been treated.
    If you use a solvent such as lacquer thinner on a swab or cloth to wipe the blued surface it will look black or a very dark blue under very bright light.
     
  14. AgX

    AgX Member

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    That would be abrasion stuff that you wiped off, or dry lubricant as MoS2. A thermically induced blueing would not be wiped off just by cotton ball or any organic solvent.
     
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