I managed to cast the lead weight in the trailing edge of the rudder today.
Before casting the lead I had to cut out the shape from the profiled rudder according to the plan; then I screwed in 6 screws as retainers for the lead. I made a mould from a piece of oak plank and a strip of soft wood. The rudder was laid on its side and the mould was clamped under the cavity to form a reservoir for the lead. Where the trailing edge was rounded I filled the gaps between it and the mould with wooden wedges. Before pouring the molten lead I supported the blade so that the upper side was horizontal by using a spirit level.
The designer, Matt Layden, calculated I would need 3 kilos of lead, which proved to be accurate.
My lead was melted by the flame of a painter’s Butane torch placed under a saucepan which was supported on two bricks; the lead was ready to pour after 15 minutes.
Tomorrow I may be able to shape the lead to follow the blade’s profile and touch up any irregularities by using thickened epoxy.
That would bring me to the stage where I’d be able to sheath the blade and its stock with GRP in the form of 6 ounce woven roving and epoxy filler.