Tag Archives: rudder

Caledonia yawl project: bevelling the stems

Today my brother Maël helped me with the beveling of the stems. This will create a bigger mating surface for the planking. This will provide a mating surface for the planks.


We did the bulk of the work with the power planer and then finished with the block plane and the spokeshave. I did notice that because the laminated stem has alternating grain, it is important to have a sharp blade to avoid ripping out any of the grain.


I also managed to do the glue up of the rudder assembly.

Next up will be setting up the station molds and getting ready to bevel the keelson. This boat will soon finally be taking shape.

Caledonia yawl project: rudder assembly 

Today with the help of my children we tackled building a couple shelves to make more room for tools. We also started working on the assembly of the retractable rudder. The plans show a little guide or sheave for the line that rudder pulls the rudder blade down. Figuring what to use for this  rather unique spot took a little creative thinking.

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Caledonia Yawl project: Carbon, Graphite and laminations

This evening was productive. 

I managed to add the Uni-directional carbon fibre to the port side of the centreboard.

  

I also laminated another knee.

  
And also covered the port side of the rudder with epoxy mixed with graphite powder (west system 423) and a little colloidal silica (west system 406). This was a big step because now I can’t see the wood grain or the Kevlar weave pattern. All that remains is the shape of the blade, which is looking good.

  

Caledonia yawl project: rudder tip and centreboard coating

This evening I was able to escape to the boat shed for a couple hours. If only I could manage on a couple hours less sleep a night I would make quick progress.

I added the last bit of Kevlar to the rudder tip

 

rudder tip gets covered with an additional layer of kevlar
 
I then started coating the centreboard with a layer of I in-thickened epoxy to seal the surface before I lay the unidirectional carbon fibre. The cedar is quite dry and sucks up most of the epoxy I painted on.

 

the wood grain really looks beautiful. (the lighter patch is where i had already coated a few weeks ago)
 
I also started to set things up to laminate the knees needed at stations 2 and 4.

the knees are a much tighter bend than the apron or stem

Caledonia Yawl Project: Rudder finishing

It is summer and quite warm in Vancouver and a now realize that I need to get my hands on some slower curing hardener. The West 205 hardener this weekend started to kick in just 15 minutes.  I’m going to go get my hands on some 206 hardener that will extend my working time in the heat.

I did manage to do one more small step in the rudder epoxy work.  I left the draped Kevlar long on the trailing edge purposefully. It was an idea I found in an article by Jim Derck called “Durable edges for centreboards and flip up rudders“.

Credit: Jim Derck in the Gougeon Brothers paper on Rudder Blades and Centerboards
Credit: Jim Derck in the Gougeon Brothers paper on Rudder Blades and Centerboards
Continue reading Caledonia Yawl Project: Rudder finishing

Caledonia Yawl project: laying Kevlar on the rudder blade

This probably lies somewhere between overkill and preventative engineering. I decided to lay some Kevlar fiber on the rudder and centreboard leading edges to deal with the wear and tear of a beach boat that will regularly come in contact with the shoreline and may at times bump up against the sand, gravel or rocks on the shoreline. In our part of the world floating or partially submerged logs and driftwood are also a concern.

Kevlar wrap over the leading edge
Kevlar wrap over the leading edge of the rudder
Continue reading Caledonia Yawl project: laying Kevlar on the rudder blade

Caledonia yawl project: final shaping of rudder and centreboard 

Experience in working on gyprock and mudding all the joints and corners and having to then sand them down to a fair blend to the straight board stock, is that it is worth spending a little more time sanding even if to the eye and to the fingers it appears to be smooth. 
  
Once I add the unidirectional carbon fibre and epoxy I will certainly discover new spots that are not quite right for the centreboard and rudder NACA profiles. Sanding down epoxy is much harder than bare cedar.

I’m feeling fairly confident about the shape now and I’m looking forward to adding the epoxy and carbon fibre.

   
 

  
This beautiful cedar will soon disappear behind layers of carbon, Kevlar and graphite. The only part of the boat I felt would benefit from additional strength beyond just wood fivers.