Wood for fingerboard extension piece

[testore]

I've used maple, macasar ebony, alder, and now poplar. Anyone notice much tonal difference? I'd like to think there's am acoustic property to them but can't tell. Anyone?

[sunburst]

I use spruce to keep mass down. I don't hear any difference in the woods I've used before.

[Bill Halsey]

For me, it's about stability of the elevated extension: ebony/ebony. I imagine that's why the added note at the bottom of the 1923 spec. sheet, after having been at it for a while. (Not in Loar's hand, BTW.)

[Dave Cohen]

In all of the interferometry I have done, I have never seen any motion in the extension that wasn't part of one of the whole-instrument bending motions anyway. So, as pointed out by John and Bill, low mass or density and stability are the two criteria. Ebony meets the stability criterion if is has been well dried and seasoned, but is about as dense as woods come. Spruce does better re the low density criterion, and is not bad in the stability department either. I don't know about alder, but I have found some Macassar ebony samples to be even denser than the average for W. African ebony. Poplar should be be OK too.

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[Eddie Blevins]

Is mahogany strong enough?

[Dale Ludewig]

Mahogany is plenty strong. I've heard they make guitar necks from the stuff.

[Bill Halsey]

Most anything can be used to hold up a fingerboard extension. My point is more about matching dimensional instabilities to achieve a more directionally stable f/b extension. For all its hardness and density, ebony is quite hygroscopic and tends to move a lot. Thus, even though maple and particularly mahogany can be more stable by themselves, pairing of dissimilar woods in this application seems to act a bit like a bimetallic strip.

For me, most important is to saw full-width fret slots and glue in the frets, to avoid downward pressure at the extension. However, no info on the o/p question of tonality.

[sunburst]

Through similar reasoning, I decided a spruce extender glued to a spruce top was a good stability match. We have to have a dissimilar wood on one side or the other of the extender, so I went with lower mass.

[austin]

I like mahogany though I use maple, too. Like Bill, I widen the last few frets, though it seems to me that the extender being quartersawn as opposed to flatsawn makes the biggest stability difference. We don't want that little guy going up and down with the weather, no matter what it is made of.

As far as an effect on the sound, I think it is important that the footprint of the extender not go beyond the head block. I can't imagine it has much sonic influence otherwise.