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Width of boards for Panel Glue Up
In article ,
reg (Gfretwell) writes:
Regardless of whether you go with narrow stock or wide to source your
panel, you still need to remember to account for seasonal expansion
and contraction across the whole panel width, however
Is there somewhere that has typical expansion rates for various types of wood?
The "rule of thumb" is 1/8" for every foot of width. A big factor is
the seasonal change of humidity in your area; another big one is
difference between working humidity and finished humidity. If you
make the furniture in an outdoor shop in August in Savannah, GA, and use
it inside in the same place, you're probably looking at a 95%
humidity environment where you worked it versus a 20% humidity
environment it'll live in. As that humidity leaves the piece, you may
end up with wood that is a significantly different size than it was
when you made it.
I don't have info available on what species expand more than others,
but I can tell you this:
Quartersawn is much better than flatsawn for all stability.
According to my _Woodworker's Guide to Wood_, these are the "Checking
and Warping Tendencies in Hardwoods:"
Low:
Alder
Basswood
Birch, paper
Cherry
Cottonwood
Elm, white
Poplar
Willow
Medium:
Apple
Ash
Birch, European or Yellow
Elm, European or rock
Hickory
Holly
Pear
Sycamore, European
Walnut
High:
Boxwood
Beech
Chestnut
Oak
Sycamore, American
-BAT
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