Official Luthiers Forum!

I've often wondered about this. Seems that it's got to do something. Spanish makers have traditionally thinned the sides out to 'weaken' them where they join the rims. And while like the Japanese master metallurgists who made superior swords by folding metal, they didn't really have the physics to back up as to why it made it better but intuitively they were very wise. I think Trevor Gore had some pages dedicated to thinning the edges.

I've always thinned out the edges of the lower bout.

I've done this purfling scheme a few times and indeed have one guitar made in the 1920's where the inlay no doubt even goes past the kerfed lining. But here there is barely .09in or so fully attached to the lining and the rest of the way the top is thinned quite a bit to the binding.

I wonder if this does indeed loosen the top and have some sort of affect on tone.

Thoughts?

A related question might be how much does gluing the purfling into that routed channel restore the stiffness.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I'm not an expert, but If you are using a glue like Tightbond and solid wood perfling strips that aren't pre-layered, I would suspect most of the strength returns in the long grain areas where it would matter most.

I too thin my tops significantly around the edges, but my binding is thinner than my sides, and the stacked perflings are .08" total with Kerfing strips that are .22" so I don't come close to the edge of the kerfing strips.

I would be worried about going more than about 1/2 way into the kerfings, but guys must do it with their shell bindings all the time. Would scare me quite a bit personally, unless I left the top full thickness and had really thin inlay.

And do you tuck the braces? Should that combination be considered?

B

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My memory is so good, sometimes I remember things that never happened.

Ah yes should have mentioned - like the rosette in this one it's individual abalone shell glued in place within a black/white black/white channel. The binding is Ivoroid.

Arthur Benade writes about clamped boundaries and hinged boundries, and in one of his "digressions" how old violins can get their purflings "stuck" and require vigorous playing to loosen things up and improve their tone. Guitar purflings may make the edge work a little more like a hinged boundry and a little less like a clamped boundry.