Friday, January 1, 2010
Its been raining here and the humidity is about 80% so I decided to investigate building a dory in aluminum. So where do you start? The bottom , This is to be an sixteen footer and four feet at the bottom. Here is a good starting point to give good lines. Start with a sheet of ply or alloy 14' 8" x 48" get the middle and draw a line across the centre both ways, from front to back and side to side. Where the lines meet the edges of the sheet draw a line to shape the bottom. "Put on the pointy bits and make them the same". You should have something like the bottom shape in the photo above.
Then the sides are made from a piece of ply or alloy cut from a sheet four feet wide and sixteen feet long sheet, cut the sheet in half length wise and here is the tricky bit. You have to measure the bottom sheet and find the exact measurement around the curved sheet. This is the only precise measurement in the whole job. With this measurement mark it on the side sheet equal distance from both ends. "In the middle on the edge" Now from these points draw a line to the corner of the sheet and this will give you the shape of the bow and stern. Dry run the side to the bottom before you cut just to make shore they are the same length. Clamp the two side sheets together and cut and they will be the same mark the sheets bow and stern so they don't go on the wrong way round. They are now ready to assemble start by tying the stems together. Now the sterns are tied together. The bottom is tied to one side at the bow and the the opposite side at the stern and work your way to the ends. When this is done the sides are forced out and this puts rocker in the bottom, the further you force them apart the more rocker you will get this is up to you. The model has 3/4" packing in the centre to bend the bottom down and the sides go out at the same time.