On Nov 23, 3:32*am, Stealth Pilot
wrote:

something for Veedubber to explore is whether epoxy saturation of the
hub area could increase the crush strength of readily available softer
woods.
laminating hard faces wont do it because they just transfer the
pressure unabated to the soft core and crush it.
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I don't know if just saturation would work. As Richard points out, on
healthy wood epoxy hardly soaks in at all. But if your hub has an
accurately made center-bore and if you make or buy drive lugs, you can
auger out the area where the drive lugs would seat and fill that area
with JB WELD or other filled epoxy. You have to wax the drive-lugs
and the bolts, and you need to get the filled epoxy deep into the
holes you've made (you don't want any of it to squeeze-out between the
prop and the hub), you'll end up with a softwood prop capable of being
torqued to hardwood specs. This is usually done as a repair
procedure. Just look at the clamping ring. If it has been drawn into
the wood by any amount you'll probably find charring between the prop
and the hub. Soaking the charred portion with epoxy will harden it
but the real problem is that the softwood prop simply lacks the
required compressive strength. That's where the filled epoxy comes
in. This also works for the valley created by the clamping ring. You
can use a WIRE BRUSH on a drill-motor to get down to clean, bare wood
then brush on a thinned coat of epoxy to act as a primer. Let it get
tacky then FILL the valley with a filled epoxy... such as JB WELD. It
will take a couple of tubes to fill a serious 'valley.' After it
cures you can sand it flush. Just make sure you keep it flat. If it
has been varnished (as opposed to epoxied) you may have to do the wire-
brush trick over the entire surface so you can apply a finish-coat of
epoxy once you've returned the surface to truth. (Tracking will tell
you if you've got it right.)

There's a lot of elderly VP's and other basic designs that, despite
their age, have accumulated relatively few hours, such as fifty hours
in fifteen years -- stuff like that. (And most of that will have been
accumulated during the first year or two.) The sale of such
airplanes is often tied to an estate sale -- the builder has died and
there's no one who can give you accurate information about the
condition of such things as the prop, engine and landing gear. And
they may not want you to go digging into it. But if you're allowed to
dig (or just remove the prop, for that matter) you'll often find
charring, especially if they've glued on a spacer to allow the prop to
clear the #3 exhaust stack.

At a real auto-parts store (as opposed to a franchise, such as Pep
Boys, et al) in the 'Dorman' trays, you will find 'drive lugs' for
about six bits as opposed to the $18 or $20 wanted for an 'aircraft'
drive lug. They don't call it a drive-lug of course -- it is a brake
part, I think for early Chrysler products.

-R.S.Hoover