Re: hollow mast progress reponse

--- Inbolger@egroups.com, fraser.howell@n... wrote:
snip I cannot easily increase the bearing surface of the
> partner, as the mast is intended to be easily stepped/unstepped.
Not sure I understand this part. How does it make it harder to
unstep?
Do you tilt the mast first? Maybe you could have a removable wedge to
spread load?

snip
>
> How about carbon fibre roving let into epoxy in a saw kerf in the
base
> of each birdsmouth?
If you use carbon, you had better use enough to take the whole load,
and it won't help if you're problem is the mast got crushed at the
partners. Carbon is MUCH stiffer than wood and will load up and fail
long before the wood can help it. Think of a rubber band reinforced
with thread.

> At least for the high stess area. Or maybe
> increasing wall thickness to 1 in.?
If you can do this, I bet it will help.

snip
> As for the increased stiffness, I think it may be that since each
of
the
> staves is quartersawn, the resulting grain pattern is nothing like
that
> of a tree. And epoxy glue lines, and less stress to hold upright.
snip
If you increased the diameter a little over the stock mast, stiffness
would have been significantly increased with the same wood. I don't
think the orientation of the grain woiuld have made much difference
to
the stiffness, though it might make it more or less vulnerable to
local loadings.

I regret that I didn't express more sympathy, I'm sure it was a very
sick feeling when it all came down.