Puzzler

[Frank Emerson]

I'll give you "where there's no joint," but I have to take exception to
"hardly ever cross grain" splitting.  Any wood will split across the grain
before it will split with the grain,  Take a 1" cube of maple, or any
species of wood, oriented with the grain as near as possible to parallel to
one face of the cube.  Drill a small hole in an end-grain face of the cube.
Chuck a center punch in a drill press, or press arbor.  Press the punch
(without turning on the spindle) into the hole.  Which direction will the
wood split, with the grain or across the grain?  I guarantee you, it will
split across the grain!

Now, we can "stack the deck" to make it more likely to split with the
grain.  We make soundboards with the grain vertically oriented, nearly 1/4"
thick, by roughly 48" wide and 48" long.  Of course it will split with the
grain, when the ratio of its thickness to either other dimensions is 1 to
192.  We can also change the odds of the direction of splitting by drilling
88 holes in the wood and inserting 88 screws (wedges) in each hole to
encourage splitting with the grain.  We can also put sandpaper on either
side of the 88 holes on a hammer flange rail to further add stress on the
rail to defy the odds, and force splitting along the grain, rather than
across the grain.  In any of these cases, reverse the grain orientation,
and the risk of splitting the wood would be radically increased.  

My point is this: Don't associate the problem to be with grain orientation,
which is a part of the solution, not a part of the problem.

Frank Emerson


> [Original Message]
> From: Ron Nossaman <rnossaman at cox.net>
> To: Pianotech List <pianotech at ptg.org>
> Date: 10/7/2007 11:32:38 PM
> Subject: Re: Puzzler
>
>
> > I've never seen a split action rail. Where and how does it split?
>
> Hardly ever cross grain, or where there's no joint...
> Ron N
>