Cutting Out Coaming Board Cubby Access and Fitting Coaming Blocks

February 17, 2020

I began by finishing up the two fasteners that I overlooked the day previous; the second to last pair of fasteners to the aft end of the port coaming board.  

With the fasteners installed, I moved on to the task of opening up the winch cubby in the port coaming board.  The small Barlow winches are mounted on a teak pad on top of these cubbing, just outboard of the coaming boards.  I began by drilling through the coaming board with a 1" forstner bit...trusting that my measurements were correct so that I would punch through in the center, more or less, of the cubby.  Success.  I gradually opened up the access hole with a jigsaw, slowly removing as much material as I could while still keeping a sufficient lip to then route a clean edge. 

My goal was to hot-glue tongue depressors (aka my epoxy, paint, and varnish stir sticks) onto the fiberglass flange of the cubby itself, and around the inside of the opening.

This effort created a fairly smooth ledge all the way around the interior of the opening; but most important, it allowed a flat surface for the router's flush cutting bit bearing to ride upon.

The result was a uniformly cut opening that mirrored the dimensions of the fiberglass opening.  I then used a round over bit on the trim router to ease the exterior edges of the opening.  By hand, I sanded the interior edges of the opening to soften things up on hands going in and out of the stowage space.

I cleaned up the edges further with 120 and then 180 grit paper.

Next, I transitioned over to the starboard coaming and repeated the process of using a forstner bit to gain access for the jigsaw, and then to rough out the opening for the router.

Again, I hot-glued the tongue depressors onto the interior fiberglass flange, and proceeded to flush cut the teak to its final dimension.

With the round over bit, I eased the exterior edge.  Finally, I sanded the interior edges and the exterior with 120 and 180 paper to finish things off.  The coamings are now to final dimension, and after taking some measurements with the coaming blocks I will be removing them for final shaping on the forward and aft ends and varnishing.

I started with the port coaming block, placing it into position on the coaming board.  There was a consistent 3/8" gap between the inboard edge of the coaming block and the exterior surface of the coachroof.  Other than this gap, the fit of the coaming block was good.  To solve for this, I will be building up this inboard edge of the coaming block with a slab of teak 3/8" thick.

I carefully measured several points on the port coaming block fit, and made notes for work back in the shop.

The starboard coaming block was a snug fit - really happy to see that.  There would be some trimming and final shaping, as would be necessary on the port coaming, but all was good here.

Pads on top of the coaming blocks will complete the installation.  Back in the shop, I prepared four thin pieces of teak by solvent-washing the surfaces, and then applied epoxy resin to the surfaces to be glued up.  I then mixed a small amount of 406 (West System, colloidal silica), and spread a thin layer onto each surface to be glued.  After assembling the teak-epoxy sandwich, I placed a layer of plastic on top and then weighted the teak sufficiently to ensure a flat product.  The next step here will be to clean up the teak assembly, and then glue it to the port coaming board. 

Total Time Today: 3 hrs