End of Bilge Board Saga ..... For Now

Boards are done and installed in the boat.  As an experiment, I decided to foil shape just one board and leave the other flat and square edged.  The plan is to record a bunch of GPS tracks of Egret's tacking angles using each board and compare the results.  It will be interesting to see if there is any measurable advantage to the shaped board.

 Trailing edge epoxy pour.  Since the volume was pretty high I filled the trailing edges in two pours to prevent a runaway exothermal disaster.  Even so, the epoxy was too hot to touch.

The pivot pin and pennant holes got filled and re-drilled.

In the spirit of gettin'er done, the board pivots remain as originally designed with new 3/4" bolts.  This is what $40 of 316 SS looks like.

I used ply templates to get a consistent shape to the leading and trailing edges.  The templates are based on the shapes I used when building the Goat Island Skiff.  Since water flows diagonally across the boards I marked off guide lines and aligned the template parallel to the water flow, in theory...

After laying out appropriate guidelines I used the plunge router and fence to cut progressively deeper grooves in the leading edge.  These grooves act as guides for the belt sander.

When the grooves disappear you are done sanding.  Takes a bit of finesse with the 36grit belt.  Minor imperfections were filled with a final skim coat of thickened epoxy.

  Same deal on the trailing edge except the guide grooves are further apart.

Almost there.

Not too shabby.

Done except for final skim coat.

Comparison of shaped and unshaped boards just before installation.  The leading edges are facing up.

Looking down on the trailing edges.

Bilge Board Gets a New Core

The hideous bilge board, dried out and getting ready for a shave.

After some scraping, chiseling and 36 grit belt sanding it looks a whole lot better.

Tracing outline onto new ply core.

Ply core cut out and lead weight holes drilled.  I bought a Lenox hole saw to match the size of the lead biscuits.  This is by far the best designed hole saw I have ever used.  Super sharp and coupled with the Bosh arm breaker drill motor it blew through the 3/4" ply in a couple seconds.  The best part is Lenox has cleverly shaped slots in the saw for clearing the cut plug with a screw driver or some-such.  They really, really work.

 I set up the ply core on edge to route a groove around the perimeter.

This groove will help key the epoxy and glass filler that will run the entire perimeter of the board.  The ply core is smaller than the skins so there will be a big fat chunk of epoxy protecting the core.

Core, lead and first skin being epoxied together.  You can see how much smaller the core is than the skin.  This  is the trailing edge so the glass-epoxy band will be deep to allow for shaping down to a relatively thin edge. 

A few hours later the second skin goes on.  It was a little warped so I had to persuade it flat with some weights and extra clamps.  The only advantage of using epoxy in Florida summer is you get things glued together pronto.....or create a huge mess if your'e too slow!  Tomorrow we seal the perimeter.