My friend Chris bought a 33′ fiberglass sailboat, a Cal 33, to use as his family cruiser. Because it was an older boat, he knew he had a few projects ahead—including drying out the wet rudder. Here in Michigan, we haul our boats out of the water for the winter and it gives us a chance to do repairs and inspect under the waterline. Continue reading
Above: The two foam halves of the rebuilt rudder, with the plywood core, are dry fit around the post before bonding.
What started out to be a relatively easy job of replacing the motor mounts and cutlass bearing on my 1983 Nelson/Marek 36 turned into building a completely new rudder. Once I removed the rudder, I had planned on fairing it and applying a WEST SYSTEM® Epoxy with 422 Barrier Coat Additive. barrier coat. However, upon closer inspection, I noticed that the rudder appeared to be bent.
A typical spade rudder for sailboats is made up of two fiberglass skins that define the shape of the rudder, a metal mandrel that is an extension of the rudder post, and foam core which bridges the space between the skins and mandrel. In order for a rudder like this to work properly, its fiberglass skins must be attached to the core and the core must be attached to the metal mandrel. Side loads on a rudder exert compression loads on the core which transfer into the mandrel. If the components become detached, the rudder can deflect excessively and eventually develop cracks in the fiberglass skins. Continue reading