By the end of the week a plank or two may well be sprouting from the backbone of the Tammie Norrie taking shape in the shed. This time around I will be taking photos of every stage, as it took a bare four months for me to forget almost everything I had painstakingly worked out for the Guillemot.
You see the plans for both boats have a datum that is based on a building frame, the plywood version being built upside down. Everything kind of self jigs, once you get the moulds set up.
But it's not done like that when you build traditionally. I needed a datum to help me set up the centreline, and that would have been the bottom of the keel, which is straight. Trying to work out the curve of the rocker and depth of the skeg, for example, was tricky, but a string through the point where the centrelines of the moulds met the waterlines was better than nothing. And in any case I was going to cut down the depth of the skeg to make the sailing version handier.
In the end I set the moulds up with legs on the floor, braced from the roof joists, the floor then becoming the datum. Once the garboards are on it'll be turned over, set up on the strongback and the moulds braced to the ceiling.
One day Iain Oughtred says he'll get round to drawing a centreline for a traditionally built Tammie Norrie. Until then, it's a case of winging it, which is why building by hand and eye, with a glance at the plans from time to time, is so much nicer than building by numbers. Albeit a bit of a head scratch from time to time.