Day 4 - Assembling the keel, finishing fairing

Day 4 began with preparing the keel for sanding and mounting of the ballast. In preparation for sanding, I marked off the area where the ballast will be positioned so I can more easily avoid sanding aggressively in that area. It should remain flat for adhesion to the ballast pieces:

Next, I marked the areas of the planned taper for the leading and trailing edges of the rudder. Here the  leading edge [R] is marked ¾ of an inch back and the trailing edge [L] is marked 1.5 inches in. The trailing edge should slope continuously to a fine edge while the leading edge should have start with a fairly fine edge but round off into more of an arc (think about the shape of an airfoil or airplane wing). Racing regulations require that 1-1/2 inches at the top of the keel and 1" at the bottom of the keel maintain at least ¼" in thickness. This area lies a bit forward of the center line giving the rudder chord its familiar airfoil shape. I marked this area off with the hash marks and vertical lines connecting the top, wider area, with the bottom, narrower area. Overall, there will be a bit more taper toward the top:

Next, I clamped the piece to my work bench and began sanding the trailing edge. Conveniently, as you sand through the first, and ultimately second layers of the plywood, the dark intermediate layers become visible and act as contour lines helping reveal the shape and its consistency along the edge:

I started out using my belt sander, with 100 grit. I found it to be way too aggressive. Instead, I used my DA sander and found it to work at just the right rate and to be very controllable:

As the following photos show, I continued to work both sides of the trailing edge, working my way toward the middle of the plywood:

As I progressed, the contour took on the desired shape and tapered nicely as it approached the keel top and bottom. Note that I was just beginning to sand into the pencil line marking where I wanted the taper to transition to the flat area marked by the hashes:

Though not entirely visible in this photo, the layers in the plywood provide a convenient guide for working the two sides toward the middle, ensuring everything stays symmetrical:

I then moved on to the leading edge. To establish the basic profile, I started by sanding on a 45° angle to the edge, setting up a faster ramp toward the desired shape of a more bulbous front edge. I then varied the angle of sanding all along the edge and smoothed everything out nicely, following the desired shape and paying attention to the lines I establish to limit the extent of the taper:

Once I was satisfied with the shape, I moved on to hand sanding the entire surface with 220 grit sandpaper. I also cleaned up the top edge of the keel on the belt sander so it would be nice and flat and free of the little bit of epoxy that was left from the gluing process:

 Next, in preparation for mounting the ballast to the keel, I sanded the flat surfaces of the ballast pieces with 220 sandpaper until they were shiny:

I drilled out the holes with a 3/16 bit to clean them up as they were a bit tight from trace amounts of epoxy left in the holes from gluing. I also remarked the shape of the ballast on both sides as a guide for where I would apply epoxy:

I applied clear epoxy to the flat surfaces of the ballast and sanded the wet epoxy into the metal surface with 220 grit sandpaper:

I applied clear epoxy within the pencil lines and a bit outside of them to allow for the fillet I would be placing around the ballast:

Then I applied the thickened epoxy mixture to the area within the pencil lines on both sides of the keel:

The ballast pieces were then loosely bolted to the keel, the pieces aligned, the bolts tightened and then I filled the bolt holes on both sides, filled in the gap between the ballast halves, built a nice fillet around the keel as it enter the ballast halves and inserted the assembly into the boat which made a convenient way to hang the assembled keel to dry:

Again, neatness helps, but all of this will get sanded down so it is not critical:

I had mentioned previously that when I faired the hull, I did only the bottom and would leave the deck side for later. I had an area along one edge of the deck where the deck was ever so slightly above the hull walls. I want a nice square edge there, especially for the method I will use for applying a mahogany laminate deck. As previously done, I used a painter's pallet knife to apply and shape the edge. This will get sanded on the next day:

I had also mentioned previously I did not get a good result with respect to getting the bow area of the deck to be flush with the hull sides. I compensated for this in the positioning of the bow piece, but decided to come back over the top with a healthy bit of epoxy as a filler. This will help ensure that I can get everything nice and level when I sand:

I touched up the pin holes in the hull walls as well:

We'll let that all dry overnight and then on to the next steps!