25864Re: another Birdsmouth spar thread.....
- Jan 3, 2003
> the spars for my Micro.I have also been thinking about
this exactly, for my Micro
Navigator. I don't know if I
have the best solution, but
the solution which I am leaning
towards is as follows:
I can buy 20' Doug Fir 2x6's in my
local Home Depot, they appear
strong and cheap. I plan to
bevel both edges of two of them
using my Skil Saw with a ripping
guide. I will then sandwich two
1 1/2"+ wide pieces in between, leaving
a roughly 1 1/2" square hollow in
the center. This will give me
a crudely hexagonal spar, which I
will then trim some more with an
electric hand plane, and later
with a belt sander.
I plan to not bevel any edges for
about three feet in length right
at the mast partner, leaving the
spar with a square cross section
of 4 1/2" right where it needs
strength the most.
The middle 2/3rds of the Navigator
mast need to be untapered and round
to accomodate the 'jaws' of the boom,
gaff, and battens called for on the
sail plan. Above the top yard, I
figure the mast can be tapered
somewhat, removing mass from where
it would help the most.
I asked PCB the question: is the 4"
untapered schedule 40 aluminum mast
on the plans 'inside' or 'outside'
He responded, I quote:
4" outside diameter; 3 1/2" I.D.
or, wood stave fir etc. mast like the
original design, but not tapered. Without
taper, the stave thickness can be reduced
to 1 1/4" or 1 1/8".
I am guessing that after I trim the 1 1/2"
Home Depot lumber to a rounded cross section
I will end up with staves around 1 1/4"
I priced the aluminum tubing and it was
$20 a foot, $400 total. Fir will cost
less than $75, a no-brainer decision,
for me at least.
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