Question about plugging holes

[mandobassman]

I know there have been quite a few guitar to octave conversions talked about lately and I'm about to start my second. My first one came out better than I anticipated but it has a pretty chunky neck and is somewhat difficult to play. The one I'm doing now has a 1-1/2" nut width instead of 1-3/4" and I think that will make it much easier to play, along with a 1-1/2" shorter scale length. The biggest difference between the first one I did and this one is the first one had a slotted headstock, which made it much easier to install standard mandolin tuners. This one has a standard flat headstock, which means I will have to plug the holes and re-drill for the mandolin tuners. What is the best way to plug the holes? I know this might seem simple, but I've never done that before and I don't want to mess it up. Is it simply a matter of finding wood dowels to fit the holes and sanding down to the headstock level or is there more to it? I know I'll have to install a veneer over the top to hide the previous holes. Any help would be greatly appreciated.

[MikeEdgerton]

Is it simply a matter of finding wood dowels to fit the holes and sanding down to the headstock level or is there more to it?

You'll either have to find dowels that fit the existing holes or bore the holes larger to accept the size dowel that you can get. That's the only way I know of to heal those holes. I would attempt to cut them as close as possible to the correct thickness to avoid excessive sanding.

[mandobassman]

Thanks Mike. That's what I figured. I'm going out tomorrow to see if I can find some dowels that will fit.

[michaelcj]

If it is drilled for "standard" gotho, grover, schaller, knockoff, closed machines the holes are probably 3/8". A 3/8" plug cutter is real cheap and a scrap of mahogany [or what ever wood the neck is made of] will allow you to cut plugs that have the same grain direction as the headstock. Better looking than end grain of hardware store dowels. Easier to touch-up and match existing finish. And if there is a headstock veneer [ebony/ rosewood etc] you can cut plugs and match that as well.

You can also buy plug cutters for other diameter holes, check woodworkers supply outlets.

[bratsche]

Ha ha, I was a glutton for punishment, and cut thin rectangular pieces off a block of mahogany (same as headstock wood), and shaped each one into a tapered dowel by putting it in my drill chuck, and running it against a sandpaper block for interminable amounts of time, removing, carefully measuring, re-inserting, sanding off more wood, etc. ad nauseum until the dowels fit. Yikes.

bratsche

[mandobassman]

Wow! I do not have the patience for that. Wood dowels will work just fine. I'm sure it looked good though.

[acousticphd]

I plugged my former tuner post holes with wood dowels. I think they were 1/4", or in any case just slightly larger than the holes.
What I did was first cut several lengths of about 1-1/2" or 2" long. Then I secured these in the chuck of my hand drill so that I could turn them (at low speed), like a "lathe". Wrapping some coarse sandpaper wrapped around the dowel, you can incrementally sand it down to a perfect, smoothly-fitting diameter. Then I cut the sized pieces carefully to length so they could be glued into the holes without any necessity for sanding down (I was not concerned with the looks).

Using a hand drill, by far the most challenging step is measuring, marking, centering, and drilling the new post holes, because you have to be within mm precision (post-to-post, and overall spacing). I made it work with some enlarging of the holes, but it was not so pretty.. I would recommend trying to make a plastic template of the tuner strip footprint, with the post centers correctly marked, and using this to mark the positions on the peghead. Or hopefully someone can suggest a more reliable and precise approach.