Thursday, November 28, 2013

Lead Pour - centerboard and rudder

Thanksgiving Day in the shop - I worked today on adding lead ballast to the centerboard (22 lbs) and the rudder (2 1/2 lbs).  The latest plans addendum was published just in time.

Starting with the centerboard, I used a large calipers to verify the thickness, marking the 13mm contour so the router would not break through at a depth of 10mm.  

I calculated how much space was needed and built a template for the router out of one of the offcuts from the kit.  I fastened the the template on with 1/2" pins driven with my Cadex 23 gauge pin nailer, which worked great.  When done, the template pulled off, leaving the pins, which I pulled with a pliers.  I cut to a depth of 10mm and left an island in the middle so the router wouldn't dive in, and later put a big base on the router and removed the island.

I did the same for the rudder, but cut these only 7.5 mm deep.

I got out my little aluminum foundry and fired it up to melt the lead.

Fun to pour metal...

There must be a bit of moisture in the plywood, as the lead bubbled and boiled.  This was a much bigger issue on the centerboard pours which have a lot more metal in them.  

Due to the bubbling, there are some voids in the underside that I may fill in after I get things smoothed out and check the final weight.

So, I'm happy with this progress today!

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