Ruddery Goodness

I've finally managed to free myself from the grips of winter and got back to work on some of the projects that need to be done.  There's still a lot of snow on the ground and it's too cold to work in the boatshed so I'm confined to the shop, but at least it's warm.

I stopped in at Goosebay sawmill last week and bought a sheet of 18mm Meranti marine plywood for the new rudder build ($155.00).  I went back and forth on whether or not to go traditional with solid mahogany planks or encapsulated plywood.  Ultimately, I chose plywood because I didn't feel comfortable enough with the movements of swollen planks and how to deal with it.  I've tangled with the properties of wet/humid wood on a number of occasions with tables and cabinets I've built, and it is really tricky to get it right.  I figured I didn't want to mess around with something as important as the rudder so I went with plywood which will be dimensionally more stable (especially once encapsulated).  The design will use two pieces of 18mm Meranti epoxied together to make a thickness of just under 1.5".

I had picked up my newly fabricated rudder post back in December and it had been sitting in my shop waiting for action.  Once I had the plywood I ripped it in half (lengthwise) and used the old rudder to trace the shape onto it.  Fortunately the maximum witdth of the old rudder is only 23" or I would have needed two sheets of plywood instead of one.

Using a saber saw, I cut proud of the traced line and then screwed on a piece of plastic laminate to create a fair arc.  I mounted a flush cut bit to the router and used the laminate as a guide to make a perfectly smooth arc along the trailing edge of the first piece of plywood.

On the front edge of the rudder where the propeller aperture is located and the post attaches, I carefully cut along the line and cleaned it up with a rasp to make sure the new rudder post would attach with the proper angle.

When I was satisfied with the shape and fit of the first piece of plywood I screwed it down to the second piece and rough cut it to the basic shape of the first using the saber saw.   I broke out the router and flush cut bit again and cut out a copy of the first.

Now that I had 2 identical copies of the rudder I could focus on setting a cove into leading edge of both pieces so the rudder post can nest into the cove once the 2 pieces are epoxied together.  The router saved the day again; using a 3/4" radius cove bit I cut a cove on each half of the rudder.  I had to shape a guide board for the aperture area for the bit that took a bit of time, but overall the process went smoothly.  I temporarily screwed the pieces together to make sure both the new and the old bottom shaft fit.  It was just about perfect.  Tomorrow, I'll make a test fit on the boat just to make sure the shafts line up properly before I cut the channels for the drift pins that will be sandwiched in the rudder.