Trial fitting the cases and the boards

Before I bond the centerboard cases in place, I wanted to make sure all the pieces fit and that the boards  were going to move freely.  Here, you are looking at the trailing edge of the port side centerboard which  is partially down.  The 1 inch Stainless bolts fit beautifully and the spacing between the boards and the insides of the cases will allow me to shim the upper portion of the boards with the perfect thickness of Delrin sheet to insure good solid positioning when they are fully loaded under sail.

Don't worry, that big ugly gaping square opening will be faired over to provide a streamlined opening for trailing edge flow transition.  I may even see if I can configure gap seals like the first sailboard that I had.


OK....enough of this centerboard pivot scene...

So here they are......I TIG welded the flanges to the threaded pivot bolt receivers and then roughed them up a bit with a grinder so that they will hold tight once they are epoxy bonded and glassed into the outsides of the centerboard cases.


neonate silencer


Although it's taken a little while to gather and configure the board pivots, I'm now at the point where I can bond the receivers onto the back sides of these cases and get these things bonded into the boat. If you absolutely run out of places to look for items for a project, I recommend Mc Master Carr . They pretty much have everything on the planet. 

One note that I should mentione is that in order to obtain a 1 inch bolt that has a 6 inch long smooth shank, I had to order a 9" bolt.  For what ever reason, there doesn't seem to be an absolute standard as to how much thread they will include on any particular bolt.  I anticipated this knowing that I will need to chop a part of the threaded ends of these bolts off so that they will not "bottom out" and rupture the external shell of the hull.  Incidentally,  1" bolts 9 inchs long tend to have 6 inches of shank and 3 inches of threads.  Just for the heck of it, I chucked these bolts into the lathe and given them a nice polished shank. Perhaps that will prevent my centerboard pivot holes from wearing over time.  ( I machined two delrin liners and bonded them into the pivot holes of the boards.  Since that material is so slippery, I cut grooves into the outside of the delrin "tubes" used a table saw to cut small longitudinal grooves lengthwise to create a "checkerboard" pattern so that they wouldn't come out once I boned them in with epoxy.  All this may be overkill but i want to dispel the idea that centerboards require more maintenance.

However, like Ian Farrier says they are a heck of a lot more work and I'm beginning to agree with him..

Centerboard pivot bolts

These centerboard bolts are about the size of a small cowboy.  The tow receiver nuts will be welded onto a couple of 3 in. diameter stainless disks with a couple of screw holes in them so that they can be recessed and bonded into the "outer" sides of the centerboard cases.  This will allow the centerboards to be inserted and pinned in place from the inside while the receiver nuts will be permanently blind mounted into the cases. I'm not a big fan of stainless on stainless because it is horrible about "galling" and locking itself into place so I plan on using lots of anti cease paste when I mount the boards.

A little lathe work to create the centerboard pivot bolt receivers


A larger tool

Well........sometimes a larger tool makes all the difference.  After spending a while with the little pneumatic stripping wheel,  I realized that a large, manly twisted steel wire wheel mounted to a "widow- maker" would allow me to get the job done quick. 

Wham, bam,...... thank you mam

Removing a bit of hull core foam

In order to strengthen the area around the slot in the hull where the centerboard case will be joined, the core foam must be removed and replaced with a high density filler. The forward exterior portion of the centerboard slot can be seen here in yellow. This is the natural color of the Kevlar sheathing that runs the 3/4 length of the boat. You can also see the inner skin which is 24 0z. triaxial glass. 
To remove a portion of the hull core foam, I found that a 3M paint stripping wheel works fairly well.  It is aggressive enough to make short work of the foam yet tame enough to prevent the fiberglass skins from being damaged in the process.