I have started marking out and cutting the bulkheads- all will be cut from 6mm ply. I am pretty busy at work at the moment, so probably wont get much more than the bulkheads cut in the next two weeks. If I am lucky, I may get some of the frames cut, which are going to be western red cedar. The frames add thickness to the plywood bulkheads, giving a much greater surface area for the side and bottom panels to be epoxied to.
The boat is a pretty simple shape - quite boxy, and has a transom, plus three bulkheads, which add to the structural strength of the hull and act as a building mould to attach the hog, chines and inwales to. The cockpit is relatively small and the boat is only 4 metres long, with bulkheads 800, 1800 and 2800mm from the transom. The cockpit is between the first two bulkheads and is only 1 metre long. This type of construction does give a lot of built in bouyancy, in two large sections - between the transom and bulkhead 1, then between bulkheads 2 and 3 (the space in front of the forward bulkhead is not actually a bouyancy tank, as it is not completely sealed, and contains the mast step).
Deciding on the shape of the bulkheads is one othe most important decisions, as the hull shape is dependant to a large degree on what I decide here.
............measure twice before cutting - I must remember that!
What space do you have to build in, Trevor? Also, what adhesives are you using? For jobs like sticking the framing to the bulkheads, I can strongly recommend a urethane glue (I've used balcotan). It's very strong, good at gap filling, single part and cheaper than epoxy (plus you waste less). Because you can use it straight out of the tube it speeds things up no end. It expands as it goes off, so you do need to rigidly clamp/nail/screw the joint together.
ReplyDeleteDave