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Hi,

I've been given some very old gabon ebony, since it's often difficult to see the grain orientation on ebony, my question is: in general is it really important for an ebony fingerboard to be perfectly quartersawn?





Thank you

Q.

In general, yes. Flatsawn Ebony can have a nasty tendency to cup, and at 1/4 thick has quite a bit of power behind it, so it can cause problems.

The good news is, with the log half in your picture, you should be able to easily identify the grain orientation and cut accordingly. Hope it's nice on the inside!

Wow! You're lucky to have that billet. Many years ago I bought two logs from Gilmer Hardwoods in Portland, Oregon of Madagascar Ebony and sawed them myself. The dust turned the whole shop black even though I had dust collection on the resaw. It's the best ebony I've ever used and I still have several fingerboards of that lovely stuff that I've hoarded for special builds. Why are you worried about "flat sawn" just be careful setting up your bandsaw and if necessary saw in radial passes. You'll end up with beautiful quartered fingerboards. What a find! That stuff is like gold.

I too have wondered about this.I see more and more flat sawn gabon boards from the smaller factory brands as time goes by.

I thought that movement in gabon would be minor because of the density of the wood itself,as long as it's well dried.

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"Practice enough till the results aren't hopes but expectations" forum member Peter Havriluk

Gabon Ebony Shrinkage - Radial: 8.3%, Tangential: 11.2%, Volumetric: 19.6%, T/R Ratio: 1.3
For comparison, the neck wood perhaps is Hog - Radial: 2.9%, Tangential: 4.3%, Volumetric: 7.5%,
EIR - Radial: 2.7%, Tangential: 5.9%, Volumetric: 8.5%
African Black Wood - Radial: 2.9%, Tangential: 4.8%, Volumetric: 7.7%.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Looks like ABW is a near perfect match for mahogany, at least on paper, Colin.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

African Blackwood is imo the perfect fingerboard wood. Except that it's expensive and hard on tool edges.

I guess most ebony blanks that end up as fingerboard are far from quartered and folks use it all the same. In my last guitar I had a better quartered piece of ebony (easier to see because it was not jet black, more of a grey black) and the pores were larger than usual. I wonder if QSawn ebony shows the pores more effectively?

Great find!

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member of the guild of professional dilettantes

I'm uncertain of the meaning of shrinkage data. As I understand it, it is done by measuring a block of green wood, then drying it and re-measuring.

What I don't know is are the stated shrinkage values indicative to what happens when a dry piece of wood is moved from a 40% RH to say, a 60% RH?

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Joe Beaver
Maker of Sawdust

I've never liked ABW for fingerboards as it is terribly stringy when routing for inlays, but loved using it for bridges. Rings like a bell when dropped on a saw table. Ebony goes "thud".

IME, the expansion rates do remain similar after drying. Ebony will always move much more than mahogany when the humidity changes. That's why fret ends poking out and cracks along the edges of the fingerboard extension are common with ebony... and why the popsicle brace was invented, to try and stop them.

But since African ebony's quartersawn rate is so high already, and flatsawn isn't that much worse, it's probably ok to use it flatsawn. You're going to have to put up with the problems it causes either way.

Some builders glue the fingerboard with epoxy rather than typical water-based glue. On a large area joint like that, the wood will absorb water from the glue and swell up, then stick in place, and then shrink after the glue dries. And since the ebony swells and shrinks more than the stuff it's being glued to, you get built-in stress. Cupping is also a problem with water-based glues, unless you spread water on the outer face to counteract it. But then you get even more expansion, and more built-in stress.

What they said...
And I like it for FB's and bridges, can't afford B & S!

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Turning squares can be a cheaper source for ABW bridges. I bought three at 1 1/2" square by 9" long that were 2nds for 50 cents/inch. Only one had a crack in one end, so 9 FB's for $13.50. I'll be getting more on Saturday.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I can't afford back and sides either Colin lol

But I do love the smell of it when I worked a few bridges in the past

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"Practice enough till the results aren't hopes but expectations" forum member Peter Havriluk

the shrinkage percents may be very similar between mahogany and ABW but I would expect ABW to gain and lose mosisture much, much more slowly than hog. I wouldn't count on them moving "together."

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.