I cut a hole in the bottom of my boat.

[Lone Star]

Dimensions are transferred to the keelson.

http://www.imagestation.com/picture/sraid225/p1fa2ce19010412746329d08bf931dab7/ea5871b8.jpg

The slot will be cut with a ½” spiral upcut bit.

http://www.imagestation.com/picture/sraid225/pfdb6ef8fb2b0ec6e9083bb0f991e4d44/ea39b53c.jpg

A template constructed from ¾” ply guides the router.

http://www.imagestation.com/picture/sraid225/p4682ebb346f45579288a7ac4478b480f/ea39b53b.jpg

The template had to be sprung down to follow the keelson.

http://www.imagestation.com/picture/sraid225/pd092076abe76de5d6d05b7c7e7119873/ea39b53a.jpg


Completed centerboard slot.

http://www.imagestation.com/picture/sraid225/p6f8c44e71b2128f2d1bdd5774fc6eea8/ea39b539.jpg

[Lone Star]

http://www.imagestation.com/album/pictures.html?id=4291501381

For all who are interested in the entire effort up to this point.

[Canoeyawl]

That is a nice job on the slot.
When I have done this, I wait until the case is built, fastened in place and then just go with a big flush trimmer bit…using the inside of the case for the guide.