Re: Wood Duck redux

Ron,

Hardwoods aren't a good choice because wood is hygroscopic; it moves
with changing water levels in the air. The grain structure adds to
this as wood's tangential movement is double what it has radially.
(That's why quarter sawn wood is used for drawer sides) This will
lead to warping and inconsistency ina product such as this. add to
this that the exposed endgrain will absorb water from the air to a
greater degree than the face and edges.

OTOH, The homogenous and binder filled structure of MDF, and to some
degree ply minimise this movement and create a stable functional
material from a raw material which is generally unsuitable for this
use. (Though some folks HAVE made successful machines from hardwood)

When you add a tensile face to the ply--as is the case with the
phenolic faced material; you gain a reduction in water absorption
surfaces--as Graham mentioned--and actually gain some stiffness from
what now is a composite stress-skin panel. The down side is
increased cost, and a huge increase in the care required during mfr.
and assembly because phenolic seems to scratch when you look at it
sideways<G> We're testing melamine faced MDF as well. Melamine faced
PB is not up to the task based on our tests.

Wood composites are a viable alternative to metal for many technical
items; it just needs to be approached from an engineering standpoint
with its pluses and minuses considered.

Thank you for your reply,

Ballendo

>In CCED, R Rogers <rogersmach@...> wrote:
>An MDF machine for a $1000, A plywood machine for $1500 ??? How
>much in hardwoods? Say Mahogany :-)
>If you can sell these, that will be good to know..
>
>ballendo <ballendo@...> wrote:
>Folks,
>If you're interested in any of the machines I described; I'd TRULY
>appreciate it if you'd let me know which of the three mentioned
>price/material options would best suit your needs and resources.
>
>And If having another size available would make you a buyer, please
>let me know that as well...
>
>Thank you,
>
>Ballendo