We got back to the daggerboard reshaping this morning by digging out a bag of foam core scraps. This would take longer, piecing together odd bits. But it’s better than waiting days for a new shipment, and that stuff is expensive. So with the little tabletop bandsaw we got busy.

I’d forgotten that the 5lb density foam core is difficult to shape with sanders. For anyone else doing this, these abrasive wheels on an angle grinder so a nice job without leaving bad gouges. Easily found at Harbor Freight, etc.

Here after rough shaping.

Then we cut off the last trailing 1″, which will get rebuilt later with solid glass and putty so as to achieve a sharp knife-edge for smooth water exit.

After lunch we ran down to Napa Autoparts for some body filler. Since this will be buried under the fiberglass, we’re not worried about exposing bondo to the sea. And it has the huge benefit of hardening in 20 minutes. So the afternoon was spent flipping the board over, sanding one side while the other had its next skim coat hardening up. It took four passes to get where we’re happy this new core will give a fair fiberglass’s surface.

Ok, the tail end is ready; now we need a plan for bulking up the forward portions. Here’s how much it needs to grow:

Anyone have a clever idea of what to use for bulking up the board? Jeanne thinks craft-shop balsa that come in thin strips, adhered to flexible matting. Or we could rip very thin cedar strips on the table saw. I’ve heard of “core mat” but don’t know anything about it. Any good experience is most welcome.

When we built the big daggerboard from the same cedar stock as the hulls, there were a couple of days where the workshop smelled like Christmas and the forest as every plane stroke during the board shaping released more cedar aroma. And then it all got sealed up with epoxy, glass and carbon, never to be seen or smelled again. Until today. It was major surgery, but at least it smelled great.

Recall the prior post where you saw how “high aspect” the foil shape was. Over 12:1, and that’s likely causing some stalling, and contributing to the howling noises when Ravenswing got up to speed. The experts agreed, it needs a more aggressive rounding shape up front and more severe taper. So we pulled out the original plans, did some tracing, resulting in some fattening and shortening fore/aft.

The board is a bit under 2-3/4″ at its widest. The exit slot at the bottom of the hull is 3-5/8″. So the new shape is going up to 3-1/3″ and 28-1/2 wide, for a 9:1 ratio. The last 11″ wide aft are too thick, so that has to go. The front 18″ or so are too narrow, so that area will be augmented over the existing shape.

Step 1, saw in to one’s well built, but poorly shaped big ass board.

Then we cut 1-1/4″ off the aft edge of the rectangular head of the board so it will fit in front of a new shock-absorbing heavy rubber insert we’ll add to the back edge inside the daggerboard trunk on the boat. Great idea from Keith!!!

Got the board level and plumb up on a makeshift table, ready for a new tail end. This feels like we’re building an airplane wing – fun.

Now we need to transfer the skinny pattern into wood and foam core. We had the off-cut from the shape-checking guide board to use in transferring the angle to the table saw. Note the light piece of wood against the saw fence is the same as what was on the dining table earlier.

So while the rest of you were out partying Friday night, we played with string and wood blocks in the tiny shed.

And in this final photo, see how the new shape will butt up against the rectangular head section. It’s those little sharp triangular areas on each side that sit on the exit slot block at the bottom of the boat when the board is deployed. This weekend we’ll fill in between these wood blocks with foam core and get this new tail shaped and ready for fiberglass. I have a feeling adding the right shape to the board on the front half will be much trickier than this aft-half job.

For those Farrier builders reading this, fear not, this surgery did not touch the super-strong area of the board (embedded hardwood insert and 6 layers of carbon uni the full length of the board). Thankfully the surgery started about 4″ aft of all that.

And while on the subject of good smelling wood, here’s a gratuitous shot of last weekend’s homework. This time the missus didn’t just hand over a photo, it was a whole how-to book of iron pipe projects. This is marital bliss – Jeanne gets to display her treasures and Greg gets to see all her treasures find a nice consolidated home. Win win, and the vacuum glides along like the shelves aren’t even there!