I do not want to make holes in the hull to fix these bilge runners.

So the only option left is to fasten them with epoxy, which is more than strong enough.

The side effect is that I have to make them the right shape before I put them on the hull. This was easily done by bending three strips of Iroco, (7 cm total thick) with the ends resting on small pieces of wood. Of course these pieces of wood are chosen sutch that the final bilge runner will match the shape of the hull.

As you can see, this worked out perfectly.

The bilge runners are 2.5 meter long, 7 cm wide and about as high.