Rundgatting Snipa in Sweden

Monday, November 9, 2015

Building a Birds Mouth Mast

Work on the coaming continues.  Each strip is clamped and glued in place.  It takes three pieces of oak to complete one strip and there are a total of three layers with five strips stacked together.  I think I have been working on the coaming for over a month.

Time to start on the hollow birds mouth mast.  As you can see finding straight wood is a problem.  I am using #2 pine with a scarf joint to get 18' pieces.  Each piece will be nailed to the jig to keep it straight as it is fed into the saw.

Here is a close up on the blade set to 45 degrees and the jig clamped down to the table saw.  On the first pass I notice the jig had a tendency to lift off the table as the end began to reach the far side of the out feed table.  I realized the rear end of the saw guide was lifting up allowing the jig to float above the saw table and distorting the saw cut.  I clamped the saw guide to the table and used hand pressure to keep the jig tight against the saw table.

Once the V-cut was complete the next step was to reset the jig to taper the stringer from 1 5/8"  to 1 1/4" for the top of the mast.  This is more fun than you might think as the jig is made from three pieces of 3/4" plywood. If I ever build another mast I will scarf the jig pieces together.  That should make life much simpler.

In order to get the pieces started in place I use a 6' starter banded together.  As I push a piece out the new long piece fits in place until all 8 pieces are fit together.  This is a dry fit to make sure everything fits together properly.

As clamps are added the V notch forces each piece to shoulder up to its neighbor and behold a nice straight mast begins to appear.

The glue up will consist of one coat of epoxy brushed into the V-notch only.   A second coat thickened to the consistency of mayonnaise will be brushed directly over the first coat before it has time to set up.  Then the 8 pieces will be clamped together and sighted for straightness and left to cure. 

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