The stems on the original boat were natural-grown crooks, which is a nice way to go for strength and simplicity. We're a little short on crooks, so the choices are either to build up the stems from multiple pieces, or to make them from bent laminations. We opted for bending them.
We made templates for inner and outer stems, taking the shape from the lofting. Using the templates, we next made a laminating fixture for the forward and aft stems. The stems vary greatly in width as they turn the corner to the keelson so at the widest point the aft inner stem has 19 laminations. The high number of laminations prevents the lamination from straightening out as it is removed from the fixture, and it makes bending the wood over the fixture easier. Besides being tremendously strong, the laminated stems are a good match for the plywood planking, since both are relatively stable dimensionally. On the down side, laminating doesn't make the most efficient use of time or materials. There is a fixture to be made, as well.
The first photo shows the forward inner stem being glued up. Plastic is used to isolate the stem from the fixture. The templates for the aft inner and outer stems are shown also.
This shows the aft inner stem planed to the final thickness (1 3/8"), and ready for trimming to profile. The lofting will be used to ensure that it mates correctly with the keelson.
We're down to the final nudges of the ribbands in the process of lining off the planking. This is fussy work. It involves moving the ribbands a fraction of an inch, sighting along the hull, and deciding if it looks better than it did.
There are some general guidelines:
1. The widest planks will be the two nearest the keel (garboard and broadstake).
2. The next plank will be a little narrower.
3. The next ones, up to the sheerstrake, will be about the same width as each other.
4. The sheerstrake will be the same as the other topside strakes, but add width equal to the gunwale so the sheerstrake doesn't look too narrow.
Now, juggle everything until it looks right.
John Gardener said something like "If it looks right, it's right. The trouble is it depends on who is doing the looking, and how much looking they have done". Amen.
A lot of the beauty of a lapstrake hull is in the determination of the lines of the plank edges. The plans sometimes (rarely) show the width of the planks at the various stations. Most of the time, the job is purely the result of the builder's eye.
In this case, the plank widths are shown on the plans. We lined off the seven planks per the plans, and attached ribbands to show the edges of the planks. We then decided that eight planks per side would better fit the sharp turn of the bilge for the given thickness of the material we are using (5mm Shelmarine® Okoume Marine Plywood)
We have almost finished the lining off with eight strakes. The additional strake improves the look of the boat, adding a little more interest, and in theory adds a little strength. But mostly it allows us to fit tight joints, and take a little more pride in our work.