the 'fitting' of the pin is just 'compression type'; meaning the pin is held in place by how tight it fits through the shoal keel. the pin is also, somewhat, held in place with the bedding compound you used to cover the ends of the pin once it was installed. you always want to inspect the pivot pin, to assure it has not 'walked' out of the keel's pivot hole, when you trailer the boat and after removing it from the water. Jerry's tolerance for the board-to-trunk-wall was small. if your new board is narrow the 'gap' will be larger so more 'room' for clunking. if a shim makes you 'sleep better at night' go for it ... i'm assuming you know you just want a shim at the 'top' of the board ('top' in this case means the portion of the board that remains in the truck when the board is extended). you don't want shims to mess with the foil shape as this will ruin the boat's windward ability and slow it down on all points of sail. see picture attached that outlines the portions of the extended centerboard that are 'inside' and 'outside' the trunk. -- :: Dave Scobie :: former M15 owner - www.freewebs.com/m15-named-scred :: M17 #375 SWEET PEA - www.m17-375.webs.com On Tue, Sep 16, 2014 at 12:41 PM, Tyler Backman <casioqv@usermail.com> wrote:
So it's nothing to worry about? My history is with swing keel boats where people generally fix this, but a short ~40lb centerboard clunking against a large contact surface is very different than an 800lb centerboard with a 6 foot pivot arm clunking against a tiny contact surface.
I was just thinking it would be possible to use g/flex epoxy to bind some HDPE (cutting board material) strips to the centerboard, creating a tighter fit. I've had good luck binding HDPE to fiberglass if it's flame treated with a torch, and glued with g/flex (made for adhering to plastics). If done lengthwise and fitted perfectly, this could also create a sort of rigid gasket at the centerboard opening, reducing turbulence and drag. I've heard centerboard gaskets improve sailing performance.
Tyler Davis, CA M15 #157 "Defiant"
On Sep 16, 2014, at 11:28 AM, Dave Scobie wrote:
'clunking' is normal when the boat is not 'driving' (in light winds). all the boats (M15, M17, S17) do this. raise the board a few inches, putting more board in the truck, can help 'quiet the board'.
-- :: Dave Scobie :: former M15 owner - www.freewebs.com/m15-named-scred :: M17 #375 SWEET PEA - www.m17-375.webs.com
