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Thread: How to polish metal parts on mandolin.

  1. #1

    Default How to polish metal parts on mandolin.

    Had great advice on a previous thread, so I'll try again
    There is significant metal parts on the head covering the tuners and the cover over the tail of the strings. Appears to be tin plated?
    What would you use to clean it up with?

    In the violin world the only parts that are metal are on the bow and those are not plated but solid alloys, and clean up of oxidation and light corrosion is usually easy with Silvo, Brasso, or in the case of plain nickel alloy I use Autosol polish.

    Would any of these cause harm to the plated metal?? ... just don't want to wear away any more than absolutely necessary.

    Appreciate your thoughts!... Mat

  2. #2

    Default Re: How to polish metal parts on mandolin.

    I would guess the metal on those parts is chrome plated, in which case any of those metal polishes should be fine.

  3. #3

    Default Re: How to polish metal parts on mandolin.

    Hi Rob... I'm not convinced it is chrome... Chrome is very mirror-like and this is rather satiny looking... or does chrome come with a soft texture? .. or is that softness all dirt can't imagine its silver!
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  4. #4

    Default Re: How to polish metal parts on mandolin.

    Matt, the metal part covering the tuners implies that it is an old mandolin, so what you see is very likely nickel electroplate over steel. Because it it has engraving, there may be a (thicker) plating of copper underneath. In any case, see if a magnet sticks, as the metal itself could even be all copper. The tailpiece is almost certainly steel, again plated with nickel. Chrome plate comes on more recent items. Nickel plate tends to be less shiny and darkens with time.
    Every electro plate can have various appearances, from shiny to matte, and even many colors.
    All plating on this type of object is very, very thin, and you can destroy it by abrasive polishing, so you can get away only a few times. You can have any metal re-plated if you want, but you have to ask around because platers are specialized, and you don’t want someone who does automotive to buff right through your engraving! Almost always, a plater will clean to base metal, removing all old plating, because it can get uneven or not work if they try to overcoat.
    You could get silver, but I think this is unusual, and you would have to keep after it.
    Some people are very concerned with cosmetic details on their instruments, and like the appearance to be exactly the same as original, or as if the instrument has naturally aged. Others like to make changes. If an antique is very valuable, it’s best to leave the finish alone, but that’s just the marketplace talking.

  5. #5

    Default Re: How to polish metal parts on mandolin.

    Hi Richard... Thanks for your thoughts... All three plates are non-magnetic... only all screws and the plates that hold the tuning gears are magnetic. The shafts and tuning gears are also non-magnetic... there does seem to be a hue of brass color coming thru... so maybe the base material is brass.

    I do want to keep the original material as authentic possible. Is there a decent non abrasive cleaner that could work? Maybe even use Brasso without a hard rub?
    Thanks for your thoughts!... Mat

  6. #6
    Registered User Greg Mirken's Avatar
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    Default Re: How to polish metal parts on mandolin.

    No, chrome plating would not have been used on an instrument of that vintage. It's nickel plating over brass, which is easy to engrave. Avoid liquid or paste polishes because they are going to leave residue in all that nice engraving. It looks appropriate as is, but you could spiff it up just a little with Nevr-Dull. This is a cotton wadding that comes in a can [lifetime supply] impregnated with petroleum-based solvents. It is not abrasive, so it's never going to make these parts look new, but that's not the goal anyway.
    Shade Tree Fretted Instrument Repair, retired
    Nevada City, California

  7. #7
    Moderator MikeEdgerton's Avatar
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    Default Re: How to polish metal parts on mandolin.

    +1 for Nevr-Dull.

    https://www.amazon.com/BASCH-GEORGE-...36037600&psc=1

    If you want to see how it works find a dull penny and start rubbing it with Nevr-Dull. It won't take out the scratches it will remove the corrosion.

    It's generally available at some Lowes, Home Depot and Wal-Mart stores.
    "It's comparable to playing a cheese slicer."
    --M. Stillion

    "Bargain instruments are no bargains if you can't play them"
    --J. Garber

  8. #8

    Default Re: How to polish metal parts on mandolin.

    Nevrdull and Brasso are similar- petroleum solvents, mild abrasive (clay), and some ammonium hydroxide to reduce oxides. Which one is more abrasive depends on how much each has evaporated and likely batch to batch. Wear gloves. A toothbrush is good on details. Rinse with clean solvents. You can protect with wax afterward. Then you can start thinking about the buttons and other stuff; lots to read on this forum! Since the gears are hidden with the plate on, clean and lube them.

  9. #9
    Moderator MikeEdgerton's Avatar
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    Default Re: How to polish metal parts on mandolin.

    It's apparent you don't have a history with Nevr-Dull. You should try it.
    Attached Thumbnails Attached Thumbnails nevrdull_polish_SDS.pdf   Brasso Metal Polish EN GHS US.pdf  
    "It's comparable to playing a cheese slicer."
    --M. Stillion

    "Bargain instruments are no bargains if you can't play them"
    --J. Garber

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  11. #10

    Default Re: How to polish metal parts on mandolin.

    Quote Originally Posted by Richard500 View Post
    Nevrdull and Brasso are similar- petroleum solvents, mild abrasive (clay), and some ammonium hydroxide to reduce oxides. Which one is more abrasive depends on how much each has evaporated and likely batch to batch. Wear gloves. A toothbrush is good on details. Rinse with clean solvents. You can protect with wax afterward. Then you can start thinking about the buttons and other stuff; lots to read on this forum! Since the gears are hidden with the plate on, clean and lube them.
    A bit off topic but I cleaned and lubed some old tuners and the owner is quite un happy with me. his tuners no longer hold. He needs new tuners. His old ones did work before I did what I thought was going to be an improvement. I have stopped using any lube. At least until I discover if there is such a thing as a lube that does not encourage slippage?

  12. #11
    two t's and one hyphen fatt-dad's Avatar
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    Default Re: How to polish metal parts on mandolin.

    tumble in walnut shells?

    (Just something I heard.)

    f-d
    ¡papá gordo ain’t no madre flaca!

    '20 A3, '30 L-1, '97 914, 2012 Cohen A5, 2012 Muth A5, '14 OM28A

  13. #12

    Default Re: How to polish metal parts on mandolin.

    Quote Originally Posted by fatt-dad View Post
    tumble in walnut shells?
    (Just something I heard.)
    Yes. As odd as it seems, walnut shells are used for some cleanup, and also as a bead-blast medium. I have a box of the stuff for the latter, but haven’t used it on anything particularly interesting. Bought it for automotive parts cleaning. Considering how fragile old plating is (lots of voids, pits, corrosion, lifting) I wouldn’t even tumble; just gentle swabbing with one of the cleaning agents mentioned. And wax after to keep the little cracks and voids from corrosion.
    And off-topic: tuners too easy! Possible, especially if the gear ratio is low (coarser worm) I imagine there was a whole range of designs, and post diameter also a variable. These days, players like high ratios for fine tuning, and these should hold better, independent of friction. I suppose that, if a customer complained of slipping tuners, one might slip in a washer to change the engagement on the post gear as it should get ‘stickier’ as it goes to a new alignment.
    Or, as the old corrupt used car dealers once were reported as doing: put something in a trannie to keep the customer from noticing the wear and rattling for a month or two. Linseed oil and sawdust.
    Last edited by MikeEdgerton; Dec-13-2020 at 10:35am. Reason: Fixed quote syntax

  14. #13
    Teacher, repair person
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    Default Re: How to polish metal parts on mandolin.

    On most fretted instruments from the late 19th to early 20th century, the plated parts are made out of brass with nickel plating.
    This plating is often thin and delicate, so it is best to avoid abrasives as much as possible.
    It doesn't hurt to start with a little water with some dish detergent and a very soft cloth.
    On the last tailpiece that I cleaned, which was silver plated, I used just a tiny bit of rottenstone in a couple of drops of oil; very gently on a very soft rag.
    If you're not sure how the plating will react, try it on the inside surface first.
    We don't normally see chrome plating until the 1930's.

  15. #14
    Registered User mtucker's Avatar
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    Default Re: How to polish metal parts on mandolin.

    It’s your instrument so do what you wish but it’s age appropriate and I’d leave it alone.

  16. #15

    Default Re: How to polish metal parts on mandolin.

    Quote Originally Posted by MikeEdgerton View Post
    It's apparent you don't have a history with Nevr-Dull. You should try it.
    You have that right, Mike... I emailed the manufacturer for the MSDS sheet yesterday, so thanks for the speedy response!!
    I'm heading into town tomorrow and will pick some up... not cheap though... $17.99 for a 142 gm can!

    Once reasonably clean, I'll seal it with Renaissance wax which I use to polish violins. This is a special preservation wax used by museums .
    https://ardec.ca/en/p/432/renaissanc...hoC2RwQAvD_BwE ... but you all are likely aware of this already.
    Cheers!... Mat

  17. #16
    Moderator MikeEdgerton's Avatar
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    Default Re: How to polish metal parts on mandolin.

    That can will last you years if you keep it sealed. I think I'm on my second can in about 15 years.
    "It's comparable to playing a cheese slicer."
    --M. Stillion

    "Bargain instruments are no bargains if you can't play them"
    --J. Garber

  18. #17

    Default Re: How to polish metal parts on mandolin.

    Quote Originally Posted by Richard500 View Post
    ....Since the gears are hidden with the plate on, clean and lube them.
    What is the usual for lubing gears? I was planning on cleaning then a very light coat of vaseline?
    Can't imagine getting into slippage with this design... Thanks again!... Mat
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  19. #18

    Default Re: How to polish metal parts on mandolin.

    Hi Folks... for the record... here is what the mondolin looks like ready to be reassembled once the metal is cleaned up...Cheers, Mat
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  20. #19
    Moderator MikeEdgerton's Avatar
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    Default Re: How to polish metal parts on mandolin.

    Our friend the late Paul Hostetter has an excellent page on maintaining and reviving tuners that his family has been gracious enough to keep alive. It can be found here.

    Don't use Vaseline.
    "It's comparable to playing a cheese slicer."
    --M. Stillion

    "Bargain instruments are no bargains if you can't play them"
    --J. Garber

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