- http://www.i550sportboat.com/). 80kg of lead will be cast and bolted to the bottom of the centre board. More pic as this project progresses. An interesting project, as these plugs are split in 2 halves with the recess machined out to accept the bottom of the centre board (centre board already machined!). The plugs were cut by locating the foam on dowels, machining the inside split line with the centre board recess. The blocks were then flipped over, located on the dowels again, so that the outside 3D shape could be machined.
Roughing pass to remove the bulk of the material.