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Reinforcing bulkhead 3

After reading the forums for a while, I started to get nervous about how big I had made my hatch openings in bulkhead 3. Compared to even the “big” openings other poeple put on the forums, mine seem larger. I started to worry a bit about how much lateral stress the mast and mast box would put on this bulkhead.

Now in reality, I probably had nothing to worry about here, as the holes I cut out have pretty hefty plywood backer plates, and I imagine almost all of the load is applied through bulkhead 3 to the surrounding cabin and deck which actually take the strain, so it’s probably just fine.

But I decided I’d retroactively add a layer of fibreglass to bulkhead 3 just in case. This would have been way easier to do before I even installed it in the boat, at the same time I cut out the access hatches in the first place, but oh well, this worked ok.

First you have to tape off the backing plate surfaces
Starboard side all taped

Then I cut out some 6oz fibreglass to size.

Clamped in place for now
Here playing with the idea of reattaching the sides (I won't)

And applied a coat of epoxy

Ready to trim
Another view

After it dried I trimmed away the extra fibreglass.

Starting to trim away excess
The tape did it's job - very little excess epoxy

Eventually three coats of epoxy were applied to fill the weave and sanded smooth. There were a couple of bubbles in the overall coat that got sanded through, but overall I think this was a success for adding a ton more strength to the bulkhead, and after paint it’ll look great.