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(Parallax) wrote in message . com...
(Parallax) wrote in message . com...
(Parallax) wrote in message om...
Got little done this weekend. The nerve of my wife thinking Mothers
Day takes precedence. However, did a little fairing of epoxy on #1
and put one side on #2. Bought a wood plane and shaped the
daggerboard of #1.

Am now leaning toward polytarp sails because I cannot get Tyvek in
great enough width and am not sure of joining pieces.

I keep finding air bubbles under the fibreglas I applied to the edges
so I keep grinding them out and filling them with epoxy. The
fibreglas seems to have been a mistake because the adhesion of the
fibreglas resin to the wood is very poor.
Found that the rudder boxes I made are twisted so I cut them apart and
reglued them between two cement blocks so they cannot twist.
No progress on #2 yesterday.

For Bookie B. You sure do things the hard way. Do ALL calculations
in metric and then convert to english units in the end. This avoids
the craziness of converting ounces to pounds and feet to furlongs etc.
At any rate, for a diameter of 2.375" and wall thickness of 1/16" vs
a diameter of 2" and wall thickness of 1/8", I get a weight ratio of
1.6X. The reccomended numbers result in a total spar weight of about
20 lbs while for my tubing I get 33 lbs.

How significant is this? Now, not all the weight is at the top and to
get an approximation I estimate the weight is centered about 6' up.
At a 30 degree angle of heel, this gives a torque of 98 foot-pounds X
sin(30) = 49 foot-lbs. difference between my tubing and reccomended.
This means my 100 lb son must sit about .5 foot further out to balance
it (I do not multiply by sin(30) cuz I assume he can adjust his body
while leaning out to make his weight vector perpendicular to the
axis.). Being 187 lbs, I would have to sit about 4" further out.
Sorry bout all this stuff, but bein an engineer/physics person, I just
luv calculating stuff.

Thanks fer yer help

Got the first coat of primer on #1. Got rudder box installed. I like
the barrel bolt idea. 4 coats of poly on rudder and centerboard. Put
mast in place and made shims for it. Assembled rigging and raised it
(without sail). Although theory says the weight of my 1/8" wall
tubing is ok, I am a little worried it is too heavy for my kids. Will
try it and see. Bought a polytarp for a sail.
No progress on #2.