Once the sides of the hull start closing up at the bow and stern, it becomes easier to install a pair of strips along the keel line and then fill in the remaining area. The first keel strip was beveled so that its edge that is along the keel line is angled to match the plane of symmetry of the kayak. I installed it much like the shear strip, simply hot glued to the stations and glued to the internal stems at the front and rear. I spent quite a bit of time adjusting its position, sighting down to make sure it was perfectly straight.
The second keel strip was planed to fit against the first on the other side of the keel line. If it’s done right, they should end up being perfectly symmetrical. Once I shaped the second strip, I glued it to the first strip and used clamps and tape to hold the joint tight.