Wood questions - Public Lumber Company, determining species at the lumberyard

http://www.publiclumber.com/2x4sitkaspruce.html Anyone had any
dealings with them? They sell "aircraft/spar-grade" 2x4 spruce for
$4.50 / lin.ft. Their prices on marine ply are about what I can get
locally, but the price on spruce beats most I've seen. Of course,
it's only a good deal if the wood is actually high-quality. Or is the
wisest course of action to just suck it up and pay AS&S's prices for
your spars and longerons?

Some plans call for specific species in specific places. At the
lumberyard, how do you tell the difference between pine, spruce, and
fir in dimensional lumber? Are they marked somehow? Guidebooks
aren't very useful - by the time the trees get to where I can buy
them, the bark and needles are long gone. :-)

Corrie

Generally, the wood itself will be stamped or marked on one or both ends
with SOME ID, which may be a little cryptic. "Western Woods" is one common
ID here in Californis, which can be about a half dozen different species.
Luckily, they all have pretty similar mechanical properties.

For a key to wood ID, try "Wood Structure and Identification", Core, Cote,
and Day. Or "What Wood Is That - A Manual of Wood Identification.

Bring a 10X loupe, and a razor knife.

BUT IT JUST DOESN'T MATTER. Read what Veeduber has to say about wood
selection in this group and in the FLY5K yahoo group. Wood selection for
QUALITY is more important than SPECIES. If the grain is OK, the wood will
probably be OK.

Sitka Spruce has lower mechanical properties than just about any commonly
available softwood used for structures - worse than Western Hemlock, Douglas
Fire, etc. But it's lighter than they are, and it's strength/weight ratio
is very high, which is why it's often called for in aircraft work.

You can build a plane just as strong with other woods, it will just weigh a
wee bit more.
--
Ryan R Young
Oakland, CA
http://users.lmi.net/~ryoung