This blog is devoted to my John Welsford designed 15' Navigator yawl Ellie. I built her in my garage over a period of 18 months and launched her in 2011. She sports a sliding gunter main, roller furled jib and sprit-boomed mizzen. Her construction is glued-lapstrake over permanent bulkheads and stringers. This blog is a record of her construction and her voyages here in the Puget Sound area and (hopefully) a useful resource for fellow Navigator builders.

Monday, September 6, 2010

Chapter 2: The Centerboard

Next, I decided to tackle the centerboard. I found an excellent guide on building centerboards and rudders on the web here:

I tried my best to follow it closely. First I ripped strips of clear Alaskan yellow cedar.

Laminated them making sure to alternate the grain direction to prevent warping.
Because Alaskan yellow cedar is fairly soft, I used mahogany on the leading and trailing edges of the board for extra strength.

I don't have a thickness planer, but I use a device called a Wagner Safe-T-Planer that works very well. It fits into a drill press and it's kinda like a 2 3/4" wide router bit. Here is a youtube video showing how it works:

I mounted the planer in the Shopsmith and wheeled the Shopsmith over my workbench. I mounted the centerboard blank on wheels and rolled it around under the planer until it was flat. Then flipped it over to do the other side. After checking it with a micrometer I was amazed at how flat it turned out.

To do the airfoil portion, I made a paper template of the airfoil shape and glued it to the bottom end of the blank.
Then I mounted the blank back on the wheels, but this time I tilted the blank so that the cutter was cutting the material outside of the template. I had to hand-carve the blend between the airfoil and the top flat section. I used a forstner bit to hollow out a section to hold the lead, filled it with lead scraps, then topped it off with epoxy & wood flour mix.  Here is the completed centerboard.

1 comment:

  1. Just wanted to say that I love your blog. I very much appreciate these details on the centerboard build, as I've read the same article and was contemplating building my centerboard the same way. I will begin my attempt at building of a SCAMP in the near future (I'm shooting to start by June), so this post has been especially helpful for me.

    Ellie is gorgeous, you must be very proud!