Although my original clamps were working well on the topsides, it became apparent that I was going to have to cut angles on the face against which the wedges were inserted as the angle between the formers and the strips increased. Also, repeated drilling through the same holes for the holding nails enlarged the holes in the timber, so that the clamps were not too stable. I therefore designed a new improved version, using aluminium U section. A small T piece which is free to rotate about 30 degrees in either direction takes care of the different strip angles, and a small block of aluminium epoxied to one side acts as a drill guide.
In the first trial of these new clamps, I tapped the holes through which the holding nails slide. I hoped to be able to lock the clamps to the formers with thumb screws, but this was not a success, as clamps moved when the toggle exerted pressure on the strips, so I fell back on using nails. Hence the above photos are the Mark 2 B clamp!