uprights: Schlz-Pllmn, M&H, Petrof, Essex...

[Ron Nossaman]

>Another question: The distributor representative said that the Ciresa
>sound boards are made with "finger joints" between the different planks of
>wood in the soundboard. This supposedly reduces the possibility of cracks
>later on. I dont' know anything about sound board construction. What is a
>"finger joint", and is this a unique thing to find in a soundboard?
>
>Charles Neuman

A finger joint is a multiple tongue and groove joint (zig-zag), most useful
for gluing short lengths of wood end to end to make long ones. Like the
ribs in Kawai's lesser grands (and no, I don't think that's what makes them
lesser). In an edge to edge joint, it's overkill. It isn't significantly
stronger than a decent butt joint (if at all), though probably easier to
cut in a production setting than a tongue and groove joint. The production
"advantage" would be in the automatic alignment of the plank edges when the
panel was in the assembly clamp, but I would think that would be offset by
the added machining and glue application hassles. The only way I can see
this sort of joint minimizing later cracking is if they used to have
problems getting a decent butt joint in the past. Panels that are going to
crack will do so whether it's at a glue joint or not. It also occurs to me
that the relative incompressibility of that kind of joint could actually
increase the likelihood of a crack forming just to either side of the limit
of the joint overlap - but perhaps not. I have seen tongue and groove panel
joints before (and I don't remember where, but I do remember the panel was
cracked), but I've never noticed finger joints.

For what it's worth,

Ron N