This last weekend I finished sanding the remaining main frame pieces to shape as well as the breasthook parts. I still have to make gussets for frames 0 and 1 as well as initial fitting of the frames together. That will come later.
Because frame 0 (the transom) is slanted 12 degrees back from vertical, the bottom edge of the transom has to be cut at an angle. I described this in a previous post. This angle needs to be cut at 12 degrees.
So I wanted to rig up a tool for cutting these angles correctly. I accomplished this by first setting the blade on my table saw to 12 degrees using a bevel gauge. Then I lowered the blade until it was just taller than the thickness of the wood I will be cutting.
The next step was to clamp two pieces of narrow wood to the fence on the table saw. One piece rested against the fence and on the table. The other was about ¼ inch above the height of the blade. The fence was then pushed up against the blade with the top of the blade angled away.
In order to cut off the correct amount of my part, I need to control the depth it can be pushed under the second piece of wood attached to the fence. So I attached a piece of wood to a sample piece at approximately ⅝ inch using drywall screws. This piece of wood will press up against the second piece of wood on the fence and control the depth of the cut on the part.
Before I ran the practice piece through the saw, I drew a line on the bottom edge so I could see how much of this edge was lost to the saw. The goal was to have the saw just miss the bottom edge of the practice part. When I ran the part through the saw, the angle was cut perfectly and the black line on the bottom edge was still there.
The process was repeated on the actual part and the cuts were made. This is the result.
It is also necessary to cut notches in this bottom edge of the frames for the longitudinal battens that will be installed later. All of the frame bottoms except frame 6 (and possibly 5) will have similar notches. However, frame 0 sets the distance the notches are from the centerline of the boat. Frame 1 will also get the notches pre-cut. It is highly important that these notches get cut accurately so that the battens lie in them. The battens will not be able to bend side to side (nor is that desirable) so the notches have to line up.
For that reason, I am only cutting the notches in frames 0 and 1. The remaining notches will be cut in the other frames after they are mounted to the building form and when I can lay the battens down to insure the notch locations are correct. This process will be covered in a later article.
But the notches in frame 0 will have to match the angle cut on the bottom of the transom edge. So I will be rigging up something to cut those notches . That will be the subject of another article as well.