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Thread: Removing lubricant from gears (Guitar, non-Mando content)

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    Registered User foldedpath's Avatar
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    Default Removing lubricant from gears (Guitar, non-Mando content)

    Okay, so this is the reverse of "my tuning gears are too stiff," and it's about a guitar not a mandolin, but the tuners are similar, so maybe it will help someone else avoid this problem.

    I made a boo-boo recently. I was doing some other restoration/setup work on one of my late 1930's metal body Dobros. The tuning gears are stock, separately mounted open-gear tuners, just whatever were available back then at a low price. The tuners are so cheap that the knobs look like they might be pot metal, or maybe pewter?

    Anyway, here's where I messed up. As part of the cleanup, I added a dab of "liquid Teflon" lube to the gears, just on general principle, even though the gears were moving smoothly. I just used a tiny amount, and was careful not to let it get into the mounting screws on the tuner plate.

    Bad idea! Now at least one of the strings doesn't want to hold pitch (the 2nd highest string, currently tuned to B for an open E tuning with a fairly heavy .017 string). I'll tune it to pitch, and immediately the gear rotates down to a lower pitch. After a few days it's not as bad... but I think it's holding mostly on friction in the nut. I have a gig next week where I'd like to use this guitar, and I can imagine a mid-tune disaster if it releases. One or two of the other strings may be a little dicey too, for holding pitch.

    So, how does one deal with an over-lubricated gear using one of these modern Teflon lubes?

    My first thought (which I haven't tried yet) was to clean it as much as possible with a Q-tip dipped in acetone... trying to remove as much of the lube as I could. Then what? Maybe a little beeswax in the gears? I'm not up for pulling the whole gear plate and soaking it, because the mounting screws are original and not all that tight to begin with. I'd rather not mess with removing and re-installing the tuning gear.
    Lebeda F-5 mandolin, redwood top
    Weber Yellowstone F-5 octave mandolin

  2. #2

    Default Re: Removing lubricant from gears (Guitar, non-Mando content)

    This is a common problem with the 6:1 open Grovers that were used up until 1938. I remove the tuners and soak them in acetone. Any loose mounting screws can be addressed by gluing in a sliver of wood with Titebond. As you probably know, any acetone on the nitro lacquer will melt it.
    A tiny amount of beeswax is all you need for lubrication.
    Grovers had pot metal (diecast) beveled buttons and square-tipped baseplates through 1934 (6:1 ratio). They were reintroduced with similar buttons after WWII, though the later ones had pointed baseplates and a 12:1 ratio.
    John

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    Default Re: Removing lubricant from gears (Guitar, non-Mando content)

    I agree with John on how to clean the tuners (naptha also works). However, I am not so sure that your problem is the lube job. Vintage open tuners are notorious for having problems with backlash from a bad fit between the worm and the gear. In time they just get worse from wear. You may have removed some crud that was helping them stay in tune. It is also possible that the gear is a bit loose. Try tightening the screw holding it in.

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    Registered User foldedpath's Avatar
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    Default Re: Removing lubricant from gears (Guitar, non-Mando content)

    John and Nevin, thanks for the info. I'll try a little acetone in-place first (beng careful of the surrounding finish), and then remove the tuners if that doesn't work.

    Nevin, you may be right about how a little crud was helping the gears hold. The cloth came away pretty black, when I wiped the gears after a dab of the Teflon lube. Maybe I should pack a little dirt from the yard in there.... (kidding). BTW, I did try tightening the gear screw, but it was already tight. Might have had some travel left, but I didn't want to force it.
    Lebeda F-5 mandolin, redwood top
    Weber Yellowstone F-5 octave mandolin

  5. #5
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    Default Re: Removing lubricant from gears (Guitar, non-Mando content)

    Violin rosin can be used to increase friction on the tuners and the tuner shaft. it is hardened tree sap so will do no harm. I suspect it would create a bit more friction than bees wax but either will likely work.
    Bart McNeil

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