Stealth Pilot wrote in message . ..
On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:

Got any info on urethane glues like Gorilla glue?

They're supposed to be good for outdoor wood projects.

Also a note on varnishing:

All film finishes for wood, paint, varnish, laquer, shellac (I think
that is all) will allow water vapor diffusion so that changes in
humidity will still cause the wood to expand and contract. What
these finishes do for the structure is to SLOW the rate of
diffusion so that any moisture gradient within the wood is
minimized. This in turn minimizes warping, but not the
overall dimensional change.

The expansion and contraction of wood with moisture content is
anisotropic. Wood expands and contracts the most along the
grain boundaries. This will be accross the fact of most boards
that you get by sawing the log through and through, that is
in the direction that was tangent to the circumfrence of the
tree. Wood expands and contracts less accross the grain, that
is in the direction that was radial in the tree trunk. It
hardly expands and contracts at all in length.

I have read that Doug Fir is uniquely stable among woods in
that it expands and contracts equally in both the radial and
circumferential directions and so it is the only wood commonly
sold as dimensional lumber while still green (others will usually
be kiln dried to 12 % MC) However, I have seen Doug Fir boards
cup and uncup with variations in humidity, indicating to me
that this is not true.

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FF