Fabricating Coaming Boards, Part 1

October 7, 2015

For some reason the fabrication of the new coaming boards had been giving me a bit of anxiety, so I decided to face the task head-on and knock it out.  I pulled the 10' mahogany boards from the shop rafters and laid them out on the lawn, set up the planer so as to have room behind and in front of it to allow the boards to pass through the planer unobstructed, and then began to take measurements.  My first task was to decide which end of the boards and which side of the boards to use for the finished surface of the coaming boards.  One of the boards had some checking on an end, and another board had some minor imperfections along the edge about mid-way down.  So having decided how to use the blanks, I set each of the original coaming boards along the blanks (more or less in their position) and used a framing square to draw a cut line across the boards.  The cut line allowed for 2 to 3 inches of additional material on either side of the original coaming board (the pattern), as the planer inevitably causing some "cupping" in the board as the board exits the planer.  Any cupping would be eliminated as I removed the new coaming board from the blank.

I then used a caliper to take a measurement of the original coaming boards to know how much material to remove from the blanks in the planing process.

Once I was happy with the measure of thickness, I set out to plane the blanks down to that desired thickness.  Each board required approximately 7 to 8 passes, while I lowered the planing cutters a bit at a time to control the removal of material.

I checked each boards' thickness with the calipers after each pass - once I had about 5 passes through the planer.  Ultimately, I left the blanks slightly thicker than the originals as I planned to sanded all surfaces smooth and needed to allow for material to be removed in the sanding process.

The boards are laid out in the shop, ready for the next step.  Sorry for the head-tilting shot.

I clamped each of the original coaming boards onto their respective blank, and then used a pencil to transfer the shape onto the blank.  I was careful to replicate any angled cuts in the original onto the blank - with notes for me to follow in the final shaping process.

With both boards traced onto the blanks, I removed the "new" coaming boards from their blanks with a jigsaw.  Happy with this task completed, I cleaned up the shop and generally prepped for the shaping process - which will occur mostly whilst sitting in the boat's cockpit.  I am not sure why I felt intimated with this step as it was rather easy and straightforward.

Total Time: 2.5 Hrs.