What caused this staining on a Junghans Dial?

Discussion in 'General Clock Discussions' started by Mark SA, Jun 17, 2018.

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  1. Mark SA

    Mark SA Registered User

    Nov 28, 2012
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    I have started cleaning a Junghans box Clock from about the 1920's there are what appear to be stains or marks on the dial.
    I have seen this kind of staining before, on other clocks.
    I am aware that aggressive cleaners can remove the numbers, and metal finish.
    Were these dials anodized or plated?
    Would a slightly acidic solution work?
    Vinegar or lemon juice mixed with distilled water?
    I wonder if this is not perhaps nicotine or oil from peoples hand that has caused the problem.

    Attempt a light clean or leave as is?

    20180617_150851.jpg
     
  2. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
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    On aged silvered dials, I use cream of tartar, or potassium bitartrate. The same cream of tartar that may be in your kitchen's spice cabinet.
    Mix a teaspoon of two with a small amount of water in a small container. Stir into a paste. Wet the dial with water. Then use a rag wet with water to apply the paste on the dial. Use moderate pressure to rub the dial with the wet rag and cream of tartar paste. You will see the dirt come off the dial.
    Then after cleaning, rinse the dial with water and gently pat dry with a towel.
    After dry, apply a quality paste wax on the dial. I use Renaissance, or Behlen's blue label wax.
    It's a gentle way to clean the dial, and should be relatively safe. You may find some of the silver is already worn, but it will remove the dirt. And the dial will remain original.
     
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  3. Mark SA

    Mark SA Registered User

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    Thank you Chris. This is most helpful.
     
  4. Willie X

    Willie X Registered User

    Feb 9, 2008
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    Mark,
    Keep your fingers crossed. You never know exactly what will happen when you attempt to 'ole dial cleaning thing'. You probably can guess how I know this. Just a warning that you need to be prepared for both the better and also the worse ...
    Note, there are at least two different types of "cream of tarter".
    Willie X
     
  5. Chris Radano

    Chris Radano Registered User

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    Always do a test on a small, inconspicuous area before attempting a more widespread cleaning application.
     
  6. gleber

    gleber Registered User

    Jun 15, 2015
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    That's helpful Willie, but are you going to leave us hanging like that? I'm glad I'm not on a bomb squad with you... "See the two wires?" "Yes, I got 'em." "Okay, good, cut the different one..."
    :confused:
     
  7. Willie X

    Willie X Registered User

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    Tom,
    I don't know what the practical differences are but one is based on a Potassium molecule and the other on an Ammonia molecule.
    MacGyver :)
     
  8. claussclocks

    claussclocks Registered User
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    I did a little quick reading and it appears the potassium version might be the better for clock uses and is the more common found in kitchen cabinets. In case you did not know, ( I didn't) it is a precipitate by-product from wine fermentation. Recommended usage is mixing with vinegar or lemon juice. The ammonium based version appears a little more aggressive. Not ready to chisel this in stone, so if anyone has further insight please share. However, as cautioned above, test in a inconspicuous area or on a salvage piece first.
     
  9. Ralph B

    Ralph B Registered User

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    As the numerals appear to be printed on the dial, and not engraved, I'd go carefully when using anything that was even mildly abrasive near them.
    I've found some old printed numerals to be a little fragile/flaky.
     
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  10. dAz57

    dAz57 Registered User

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    #10 dAz57, Jun 18, 2018
    Last edited: Jun 18, 2018
    Photograph and photocopy the dial before you do anything, and be prepared to reink the dial because you will not get matching fonts.

    The dial isn't that bad, I would wipe over a soft cloth with Coleman's fuel to remove any old oil and grease and then leave it alone.

    What you have is thin lacquer applied over printed numerals, go through the lacquer and the numbers will come off, as it is the dial is in good condition, the printing is clear and not rubbed off.

    I will repeat, any attempt to clean this will make it worst, leave it alone.
     
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  11. claussclocks

    claussclocks Registered User
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    Sounds like good conservative advice to me. You could end up with a faceless clock
     
  12. Willie X

    Willie X Registered User

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    Yep, some dials are silk screened with water soluble paint. I'm talking about (sometimes) very soluble paint.
    Willie X
     
  13. gleber

    gleber Registered User

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    Does anyone know if there is/was a reason to use water soluble paint/ ink? Seems shortsighted to me.

    Tom
     
  14. claussclocks

    claussclocks Registered User
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    Too early for EPA and others to get involved like they did with water based auto paints in early 80's. After a few years it looked like you painted your car with Tempra paint. My guess would be, easily available, inexpensive, and looked good when it was put on. After all, how many of these people would have guessed we'd still be keeping and fixing these clocks after almost a century.
     
  15. Mark SA

    Mark SA Registered User

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    Thank you Willie
     
  16. Mark SA

    Mark SA Registered User

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    Will do Chris. Thank you.
     

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