Hi Roy,

We have two plywood boats, and on the rear beams the bolts come up from the bottom and the nuts are inside the beam. (Can't have bolt heads on the top of the rear beam because of the traveller track).

Having nuts inside the beam is problematic as the inside ones are almost impossible to hold with a spanner. So I welded nuts onto pieces of square 3mm ss so that the nuts can't turn inside the beam. I also ground the ends of the bolts to a point, so as to make it easy to locate the bolts into the nuts.

The bolts on the rear beam of 1434 had 1" square Aluminium washers under the heads of them, but years of tightening had caused the washers to crush into the timber. (No doubt the holes in the timber are also elongated, like yours.) So I replaced the 1" square Al washers with large rectangular 3mm ss washers, (about 40mm x 75mm) so as to spread the load on the timber, and did them up really tight. I suppose I should fix up the elongated holes like you did, but maybe I won't.

Regards,
Greg.

PS If you are having trouble getting you arm stuck in the hatches, try using a lubricant.