Sunday, September 30, 2007
Saturday, September 29, 2007
The first step is to apply a fillet of wood flour thickened epoxy to the joints which will provide a smooth radius for the fiberglass tape to come. The epoxy is mixed t0 peanut butter consistency, which makes it reasonably easy to apply with a wood tongue depressor, then smooth with a rubber spatula cut to the appropriate radius. The only difficulties I ran into was the fillet on the joint between the sheer panel and the bilge panel. Near the stern, this joint had almost no angle (or a 180-degree angle), which made a clean fillet more difficult.
Tuesday, September 25, 2007
Sunday, September 23, 2007
Saturday, September 22, 2007
Wednesday, September 19, 2007
Saturday, September 15, 2007
The first order of business today was to create some more clamps that would be used in attaching sheerclamps to the sheerstrake. The length of the boat would require more clamps than I had on hand, even after building a Passagemaker dinghy. To supplement my supply, I used a tip from the CLC page, and made clamps from 4" Schedule 40 PVC pipe. The pipe was cut in 1.5" segments, which were then split to create an inexpensive yet useful clamp. In about an hour, I was able to turn out about 30 additional clamps.
The bottom panel was scarfed together, using the same technique as described yesterday for the side panels. The panel was masked on either side of the joint with clear packing tape, then the scarf joint was coated with silica-thickened epoxy. The two pieces of the panel were joined and the panel aligned before being weighted with 2-1/2 gallons of Eipersbräu minikegs.
Next, the sheerclamps were attached to the sheer panel. Careful consultation of the instruction manual was required to make sure the sheerclamp was attached to the correct edge of each panel. The edge was coated with thickened epoxy, the clamps placed and aligned, then clamped down and epoxy drips were wiped up. This completes the prep work of hull parts; stitching of the hull is the next task. Total hours 3.50.
Friday, September 14, 2007
Tonight begins the building process. As with almost all kits from Chesapeake Light Craft, the building process begins with the scarfing of some parts. Scarfing refers to the joining together of small parts to make larger ones. In this case, the side panels of the 16-foot-long boat must be comprised of smaller parts cut from 8-foot-long plywood sheets. The plywood can be joined with epoxy to which silica powder has been added to increase strength. In researching the building of a Mill Creek kayak, I read WoodenBoat magazine #136 (May/June 1997), the first in a two part series focusing on building the Mill Creek. By happy coincidence, the same issue contains an article by Greg Rössel on scarf joints.
I started by wrapping the area adjacent the beveled ends of the panels with clear packing tape, which will protect from epoxy spreading outside the joint. The bevelled ends come in the kit pre-cut, which is very convenient. These are cut at an 8:1 ratio, meaning the bevel surface is 8 times as long as the thickness of the plywood. This falls within the recommended range of the WoodenBoat article which suggests going even to 12:1. To epoxy the ends, I coated each surface with unthickened epoxy, allowing it to soak into the end grain. I then coated each joint with epoxy thickened with silica to mustard consistency. Using a sheet of plastic to separate each panel and prevent them sticking together, I stacked corresponding bilge and sheer panels on each other, and weighted down the joint. To get the correct alignment of the panel, a string was run from one end to the other, and the panels adjusted until the specified distance to the arch of the panel was achieved. The scarfing process was also repeated with the sheerclamps, which will form the attachment point for the joint between the deck and the hull. The epoxy will be allowed to cure overnight, in a shop that is now at about 80 degrees F. (Total hours: 2.00)