Laminated ribs

[Delwin D Fandrich]

----- Original Message -----
From: "Ron Nossaman" <RNossaman@cox.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: August 18, 2003 8:21 AM
Subject: Re: Laminated ribs


>
> > > As long as the glue holds, it's a solid piece of wood.
> >
> >
> >Well, not quite. In a bent lamination the outside (convex) laminae are
> >under some amount of compression and the inside (concave) laminae are
under
> >some amount of tension. How much depends on the material used, the
radius,
> >the height of the bent lamination, etc. But that is what holds it in a
> >curve.
> >
> >Del
>
> But then I've cut many a solid piece of wood and watched the internal
> stresses bend what I'd cut farther than the laminations were bent to make
a
> rib.
>
> Ron N


True. Especially with maple--doesn't anybody know how to dry that stuff any
more--but spruce, at least the spruce we get, seems to be relatively
stable. The advantage of the bent laminate is that the stresses are
predictable.

Del