Greg,
Bill at Forte Spars is removing my old mast track and replacing it with new
track bonded with Plexus. He said the removal of the old track is easy
compared to removing the 5200 from the old track. He also recommended plain
old
marine varnish on the spars for UV protection after a light sanding with
Scotch-Bite pads. He showed me an example that looked great. This solution is
cheaper
and easier than 2 part polyurethane.
Regarding the adhesive-backed HMW sheet for the vang shim, I could not figure
out which part number/section of the McMaster Carr web site to locate the
stock and thickness that I need. If you could point me to the right page, that
would help. Based on your suggestions and Bram's second, the vang
sleeve/collar setup is the way to go.
Thanks,
Bill Scheumann
In a message dated 7/13/2006 11:40:26 PM Eastern Daylight Time,
gregoryrryan@xxxxxxxxxxx writes:
> Bill, before you take the mast to Tony DeLima, if you have removed the
> track, sand the bugger with your ROS and 80 grit and get that outer epoxy
> coating
> down to the Carbon. You will not regret it. Coat later with 2pt LPU, I have
> some I can share with you, if you need, in either clear or white. You
> willonly use a small part of a can.
>
Its not even hard to make. Just wrap the sleeve slightly big in diameter and
length (wrap 3-5 layers of Mylar under the carbon windings using the actual
mast tube as a mandrill), measure the gap of the fit and order the adhesive
back
HMW sheet of the appropriate thickness from McMaster Carr (comes in 2 days).
Make the two collars (in one piece) by winding several to quite a few layers
of 3" carbon uni around with only a thin layer of Mylar windings over the
sleeve as a mandrill. On those windings put your nylon bushes (or use a bit of
SS tube from me) and a few more outer windings to bind it all in, check
alignment of the bushes is parallel to axis. The collars seem aesthetically a
bit
thick in my diagram to allow a bit of meat to thread the spring pull pin into.
Fill in any vacuoles with epoxy 410 peanut butter. When the epoxy is set,
table saw the sleeve ends and the collars into two and make the ends neat.
Then
run the sleeve through the table saw longitudinally to make the keyway. Epoxy
the collars on the ends of the newly slit sleeve, without twist (by lying
sideways on the bench), at the correct spacing of course - based on the height
of
your vang pivot piece. Just use a small hand file to remove some of the
material from the collars over the keyway so that the keyway is clear from top
to
bottom and you are done. The ring pull pin can be screwed into a 3/8 #16
course
thread hole tapped in the front.
To make the key, use your oldest kitchen HMWPE cutting board put through the
table saw to make material of the right width and height. I drilled the rivet
holes in the key and then used a forstner bit to countersink the pop rivet
heads. Make a few extras to hand out to your mates.
I'd suggest you don't drill any locating holes in your mast untill the boat
is rigged with mainsail up and mainsheet on. Set the vang lever to the
middle of its throw and remove the spring pull pin and drill your 1/4 inch hole
in the
mast face for a perfect fit. Add locating holes as required for more vang
throw.
Good luck with it, however you decide to build it!
Greg
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