On Dec 14, 9:14*pm, "Capt. Geoffrey Thorpe" The Sea Hawk @See My
Sig.com wrote:
wrote in message

... To All:

...*Maple laminae a quarter of an inch thick is the
goal to shoot for but few amateurs are lucky enough to have access to
such material. *In fact, most amateurs are stuck with using whatever
is available from the local Borg -- typically birch in 3/4" thickness.

I've never seen solid birch lumber in a Borg, nor can I recall
a Borg that did not carry solid maple. But what they carry will
depend a lot on what grows locally. Doug Fir is scarce out here too.
Poplar is as cheap as pine.'

Regardless, select straight-grained wood. Avoid any wood with a
wavy or quilted surface or wild grain.

Near any big city you will find one or more hardwood lumber dealers
who will carry or can order any common North American hardwood --
for a price.


Ask around. Likely you know _someone_ with a thickness planer that would be
willing to run a couple dozen feet of lumber for you. Not all of them may
get you down to 1/4 inch, but you can get down below 1/2...

(I never knew how handy one could be until I got one)


With any planer I have ever used you can get down to 1/8" by
fastening the workpiece to a thicker board using double sticky
(not foam backed) carpet tape. The trick is getting it apart after
planing. Use a LOT less tape than you think you'll need.
Lacquer thinner will soften the glue on the tape if you can't
get it apart any other way.

That works well for planing short pieces too.

Resawing is the practice of cutting a thick board into two
or more thinner boards, as opposed to ripping which makes
narrower boards from wider ones.

With a good bandsaw and a little practice you can resaw 3/4"
lumber to get two pieces each near 5/16 and then plane it
down from there, rather than planing all the way down from
3/4" to 1/4" or so wasting most of the wood.

You can also resaw on a table saw if the board isn't too
wide, here's how:

You raise the blade up until it will cut about one half inch shy
of the middle of the board and make one pass against the
rip fence. Then flip the board so that the same side is against
the fence and cut from the other side. Then finish with a
hand saw. Leaving an inch or so in the middle to cut by hand
prevents the kerf from pinching the blade.

Resawn Borg lumber will often cup due to residual stresses
left over from rapid kiln drying. If it does, try repeatedly
moistening and heating the the concave side until it is
the convex side and then let it dry for several days.

You don't want residual stresses in your propeller. If you
eschew resawing and plane all the way down from full
thickness, plane equal amounts from each side to
minimize cupping.

You can also get more (and probably better) advice
from rec.woowdorking, er, rec.woodworking.

--

FF