Sunday, 16 March 2014

Adding an inner forestay - Part 2

Making the bulkhead

(see Part 1) The new bulkhead is made from 12mm marine ply laminated with a layer of biaxial fiberglass cloth on each side. All structural boltholes are reinforced with solid fiberglass laminate to withstand both radial loads and axial compression. We added two watertight access hatches - you never know when the chain behind a permanent bulkhead will get tangled! Overall, making the balkhead took many tens of hours of work. Here's the "making of".
Marking, cutting holes, sanding


  • 12mm marine plywood
  • West System 205 epoxy resin (from
  • West System 105 (fast) and 106 (slow) hardener
  • 450g biaxial glass fiber cloth
  • Chopped glass strand
  • Henderson TCL4 watertight hatches


  • jig saw, hole saw
  • Dremel
  • drill, drill bits
  • hand plane, sand paper
  • brushes, mixing cups, spatulas

Step 1 - fitting & cutting

Bevelling, cutting fiberglass cloth
First, we had to cut the plywood to the right shape. We started with an mdf template, which we also used to laminate a fiberglass lip to the hull and deck. We then cut the the plywood to fit, leaving a gap of a few mm all around to be filled with epoxy putty later. We marked out the approximate position of the boltholes for the inner stay bracket, and cut oversized holes around each. Each cutout was bevelled and the board sanded for better adhesion. We then cut biaxial cloth to cover each side, plus patches to fill the cutouts and an additional reinforcement strip.

Step 2 - laminating

Fililng holes, wetting out glassfiber cloth, compression weight
After wetting out the "cabin" side of the board and the cloth, we applied the latter to the former, and used a roller to remove excess epoxy. After turning the board over, we filled the cutouts, wetting out and compressing each layer, applied the reinforcement strip and finally the outer layer to the "chain" side. To provide a smooth finish in the bracket area and squeeze out any excess epoxy, we then applied some weight on top while the laminate cured.

Step 3 - fitting the hatches

Cleaning up the edge, marking hatches, cutting, drilling holes

Filling bulkhead mounting holes, re-drilling, final layer of epoxy

Step 4 - finishing touches

Both sides were sanded, an additional layer of epoxy was applied, and the result sanded again - ready for gluing and painting. 

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