Centerboard Edge Filler

Today I got some more work in on the centerboard (CB).  Below you can see the centerboard glued together and all clamps removed.  You can also see that I have cut a rabbet or groove in the leading edge of the board.  The rabbet also goes around the trailing edge of the board, which you cannot see (the trailing edge is on the rightmost end of the board).

Centerboard, Glued and Rabbeted

Router Table

This is my trusty router table I used for cutting the rabbet.  It is clamped to the Black & Decker Workmate folding bench my dad gave me about 40 years ago.  There are a couple spots in the rabbet that are wider because I wiggled the board a bit.  I might have been able to do a better job with the router hand-held and a fence mounted on it--but then again I  might have done a worse job!  Well, I decided on the router table and I think it was a good decision.  The rabbet is OK and any wobbles will be filled with epoxy.

CB Rabbet Filled

This is the rabbet right after the first application of thickened epoxy filler along the leading edge.  I thickened the epoxy with approximately two parts wood flour to one part colloidal silica.  The filler looks a little rough here.  After a couple hours I went back and smoothed it down some with a gloved finger dipped in denatured alcohol.

Filler Smoothed

Here's the filler after some smoothing with denatured alcohol.  It's not perfect, but this will save me a lot of sanding.  Getting the epoxy as smooth as possible while it is pliable saves many hours of sanding or chiseling later.  The edges of the centerboard will be ground down to a somewhat airfoil shape, bullet-nosed in front with a longer taper in back--so the edges of the tapers will be all epoxy.  The epoxy will make it much less susceptible to damage by underwater objects.  I plan to also add dynel cloth and an epoxy/graphite mixture to the leading edge.  (Graphite/epoxy will also be used in the final coat on the entire board to make it slide more smoothly in the trunk.)  Why am I being so "anal" about protecting the centerboard?  It is going to always be inside the trunk and next to impossible to get to without a crane to lift the boat off the trailer (I have some other ideas about how to raise the boat but they may or may not work).  So you can see why I am doing all I can to protect the centerboard and its trunk from damage.  I may not even know about any damage until it is too late and water has infiltrated the board.  Besides the obvious problems, this can make it swell and become permanently stuck inside the trunk--not a good thing.