I'm about to build my first model racing yacht out of machined CoreCell
covered with 2 oz glass outside and 3/4 oz glass inside, using
Aerospace Composites resin. This will be a 36" LOA, 12 lb free sail
(vane steered, no radio) boat that has to be designed to take the
stress loads of hitting the side of a pond when surfing under
spinnaker.

Current plans are to hollow the hull to 1/4" wall, with a 1" wide,
full depth "keel" running down the center, and gunwales widened to 1"
where the shrouds attach. The 9+ lb bulb will be removable, with two
1/8" stainless rods running up through carbon fiber tubes set in the
CoreCell "keel" and bolted at deck level. Back of the envelope
calculations suggest that this should yield a boat a bit lighter, just
as strong, and much simpler to build than my current technique of
spruce scantlings inside a glass shell.

I am concerned about shroud/stay attachment, given the stress the rig
takes if/when it whacks the side of the pond. With the spruce
scantlings I put 1/4" thick pads of Lexan under the kingplank and sheer
strakes and screw #4 stainless sheet metal screws into them. This has
never let go on me, even under the stress of some pretty horrific
collisions.

Having never worked with this stuff before, the only thing I can think
of is to inset the Lexan into the CoreCell and cover it with a couple
of layers of heavy glass. Anybody have any better ideas?

Any other cautions or advice welcome.

(FYI: This boat will be sailed at Gosport, England in late June, in the
biennial UK/USA free sailing free sailing and hospitality
championships.)

Cheers,

Earl

You're only allowed to followup to your own posts if you're past
retirement age :-)

Forgot to mention, 5lb foam.

Cheers,

Earl

Earl,
Chainplates are the easy part. ;-)
Simply _narrow_ the core at the deckedge, and wrap glass over a tube of the
correct size for the pin you want to attach the shrouds with. Then trim out
the middle by the width of the toggle, position toggle and slide in pin from
the end. A glass chainplate totally integral with the hull.
You can do the same at the bow, since I'm assuming you will have a rubber or
balsa "bounce bow" in front of a structural flat. Just do the headstay on the
flat.
Any questions, email me and I'll draw some piccies for you ;-)

Steve "hasn't sailed a boat at Gosport since 1979..."

Stephen C. Baker - Yacht Designer
http://members.aol.com/SailDesign/pr...cbweb/home.htm