MikeG wrote:

In article ,
says...
I am building a kitchen hutch out of primavera, also known as "white
mahogany". The wood was purchased from an importer with a kiln, so it is
kiln dried. I milled the wood to 3/4", glued up a bunch of panels
roughly
16 inches wide, composed of 3 boards 5 to 6 inches wide. All was well
for a
couple of weeks. Then, when I started assembling the hutch, I discovered
my panels are cupped across the grain - roughly 3/16 of an inch across 16
inches. Not all of them are cupped, but perhaps half of 20 panels are.
The
moisture content is 12 to 14%, which seems high. I can't tell any
significant difference between cupped and uncupped panels. My genuine
mahogany and some oak, also stored in the shop, both measure around 8%.
I've noticed that the cupped panels will "uncup" over a few days, then
re-cup.

Any ideas why this is happening? Are the panels useable? I'm thinking
not.

Also, when you glue up panels, should they be stickered while stored?
I've always just stacked 'em up on some sawhorses or whatever is handy.

This is the first time I've worked with primavera, so maybe it's just not
a good species to use for furniture...

Thanks.

Bob





12% MC for furniture making is high. It should be around 8%. Just
because the importer and the wood was kiln dried doesn't mean it was
kiln dried properly. Did you check it before you bought it?

If, in fact, the wood was at around 8% when you bought it and now is at
12%, of course you should have stickered it. Then there is the
environment the panels were stored in and the environmentt that you kept
the individual boards in before working them and how long before and
after milling they sat. Were the boards stickered and allowed to
acclimate to the new environment of your shop before and after milling?

Those are just a few of the things that can go wrong and then there is
the fact that sometimes wood just takes it into it's own mind to warp no
matter what you do.

FWIW, the FPL database says of African Primavera that "movement in service
is rated as small". That is the normal commercial species. However there
are also four different South American "primavera"s, and given the amount
of wood that seems to be coming in from South America these days it could
be one of them instead. The most common is a relative of ipe and if it's
anything like ipe should be pretty stable and pretty near indestructible,
but the other two I can't find any information about.



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--John
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