Plug and re-drill mandolin peghead

[Paul Statman]

In 1982 in England the only replacement tuners were Schaller MNI3, sold as a replacement for Gibson mandolins. A novice, I knew not of spacing and gear orientation. I drilled them (gasp) all the way through to accommodate the fat Schaller ferrules. At the time I was just desperate to have a serviceable mandolin. Please don't hate me for what I did to my 1923 snakehead. I feel bad enough.

Q: Now that Stew-Mac offer the relic replacement tuners, what is the accepted method (actually I'll hire a luthier this time) to plug and drill new holes? I've bought the Loar era jig, too, but my local repair guy says you can't drill down the grain, even with a jig. 

Is there a source for cross-grain mahogany(?) dowel for this purpose? The holes now measure ∅ 10.28mm

This is what I've come up with. Is this a good way to go? That's a 3 ⁄8"∅ tapered plug, ¼" deep.

[Grahame Myers]

Here's what I use for these kind of repairs: http://www.axminster.co.uk/plug-cutters-and-plugs-dept811900_pg1/ Scroll down the page a bit, I have the plug-cutters from Veritas, not the cheapo Axminster ones. They have a very slight taper: you can tap them into the hole after applying a small amount of glue until the're tight. After the glue has set, saw the rest off with a flexible razor saw, and they are almost invisible.

Grahame

[Paul Statman]

Thanks, Grahame~

I used a plug-cutter that looks like the Veritas ones. Scraping the excess glue today..photos later.

[Paul Statman]

Drilled, fitted, and strung up.

[Grahame Myers]

Nice job, it's turned out well! maybe you should fill the two screwholes that are still visible, and then it'd be perfect. Plug them with toothpicks glued in with a drop of CA, saw them off flush, and then disguise them with stain to match the rest of the wood.

Grahame

[Paul Statman]

Thanks, Grahame ~ I had thought of doing that. I may get around to it later. I don't have easy access to a workshop. I bum the use of a friend's garage workbench, when I can. I am very pleased with the way this turned out. If I ever do this operation again in the future, I'll use end grain dowel.

[Paul Statman]

Thanks to everyone who contributed to this discussion. I didn't get them at first - until I found them in my SPAM box (thanks to yahoo!). Big thanks to Frank Ford, who took my call (when I thought this board had rejected me), and was so generous with his time and expertise on the phone.

Best wishes to you all,
Paul Statman

[Paul Statman]

I took some better shots yesterday (because they didn't show up when I clicked on this thread..because they're on page two), and no, I haven't filled the holes yet..

I'm about to tackle a very similar situation on a (Paul) Newson I just got with Waverly tuners. The holes are drilled per Paul Hostetter's #3 diagram, I.E. the hole is the diameter (or slightly larger for a somewhat less-than-snug fit) of the collar (bushing). Waverly tuners don't like this, for some reason, so I'm going back to square one in hopes of getting the post gear to mesh properly with the worm gear. Several of them under tension are pulled apart, creating a full 90° of play. Tuning is a nightmare. Maybe if I replaced the tuners with a less 'engineered' Gotoh set, they would be more forgiving, and I could avoid surgery altogether?

[Ned Knepp]

Hi Paul.

  I don't know if this was already discussed in the thread because I can't remember that far back but I want to point out that compared to my snakehead, your tuners are mounted on the wrong sides. The gear should be down so that the string tensions pulls the shaft gear into the worm gear. It may clear up your tuning issue if you switch the heads around so the gears are below the knob.

[Paul Hostetter]

Snakeheads have worm-under machines. I think he did the right thing.

[Paul Statman]

Thanks, Paul.

I had previously reamed out the original holes to fit the later post spacing required to accommodate the Schallers I was fitting to replace the originals. In my opinion, no gears in this 'modern' (from around late 1924) configuration of 'worm over gear' can 

a) look right on a '20s snakehead, or

b) work right when reversed. They turn backwards. 

They are also too heavy for the balance of the instrument. The new 'vintage replacement' are the almost perfect weight and almost perfect fit (- see the original wiggle end marks in the wood).

[Ned Knepp]

Paul, I recognize and appreciate that you have much greater experience than I do and normally I'd bow to that but the pictures Paul S. posted shows screw holes in the backs of the head above the existing machine plate which seem to indicate that there were tuners on it that were mounted the other way around at some point.  Beside that, my snakehead is the other way around and it hasn't been modified.  I don't know how to reconcile what you are saying with that I see.

I'm editing this to say that a quick search on the internet netted me pictures of snakeheads with tuners mounted both ways. I found three on the Elderly site with tuners mounted like mine. All have the (cheap) square steel plate and steel gears. 

I understand that Gibson has been known to mix up thing a bit on productions runs. Some of these instruments have no script on the head, some have it at an angle and some have it squared up on the head. I suggest that perhaps Gibson sometime mounted the tuners with the peg up and sometimes down. If that is the case Paul can still switch the heads around which should help his tuning problem and still be original.