Thursday, October 21, 2010
Building ‘Sharpy’ Part 11
Today I did a total of 4 hours in the garage. I worked on the forward side panels and smoothed the edges of the frames. I have now cut out the hull side panels, but not the keel box support frame, which can only be done when the side panels have been assembled to form the shape of the boat. The reason for this is that the exact dimensions for the keel box support frame cannot be known until the side panels have been joined to all four frames, and the two-part transom. When they have been glued together, including the internal stem post, the panels for the bottom of the boat can be cut to size and fitted. It is important that the chine logs and sheer strakes have first been glued to the side panels before they are assembled to form the shape of the boat.
I shall have to consider whether to thicken the three-eighths plywood frames along their edges for better adhesion and to give more bulk for the nails or screws that will hold them in place to the side panels. Mr. Anonymous, who is building a ‘Sharpy’ in the US, did thicken the sides of his frames by gluing a beading to them. There will be no need to thicken the keel box support frame because it is made from a 6 millimetres thick piece of plywood. The plans show an epoxy fillet on the forward side of frame 3 to which the forward end of the keel box is joined. That makes a lot of sense, because that is the area where most stress will be located because of the forces imposed by the keel. It would be prudent to put epoxy fillets on both sides of frame number 3 because it also takes the load of the keel where the Bowden cable runs over the top of a pulley located in a bracket at the forward end of the cockpit.
My next job will be to make the internal stem piece and the internal edge supports for the transom, because until they are in place, I cannot do a trial assembly of the side panels to find out if they fit properly to the frames. Only then, if all the edges line up can I glue the chine logs and sheer strake to the side panels before the final assembly.
Because Derek Munnion does not include a building instruction manual with the boat plans, builders have to work out the order of assembly, but if there is a problem, Derek is always pleased to offer advice over the phone, or by email.
He is currently changing his Internet Supplier; therefore his old email address is defunct. When he gives me his new email address, I’ll post it here at my Blog. Meanwhile if you want plans, please contact me, either through the Blog comments page, or by email to: firstname.lastname@example.org . I’ll put you in touch with Derek. Plans are currently £40.00 for UK residents and slightly more for those who live elsewhere in Europe, the USA or another country. Study plans are £4.00 worldwide.