Rebuilding the Backstay Bulkhead (water issue)

My fall inspection of the boat revealed a leaking backstay chain plate that should have been rebedded when I did the rest of them in 2010. Water had leaked into the knee where the chainplate attaches, and with cold weather that was coming, the water surely would freeze and expand enough to delaminate the fiberglass tabbing.

I drilled weep holes to see how much water had come in

Here is the original knee

Once the weather started to get warmer in spring, it was time to cut out the old bulkhead.  I purchased the best tool in the world for this job… a Dremel Multi-Max Oscillating Kit. The flush cutting blade was awesome at getting a close cut to the hull, and it made quick work of the fiberglass and plywood.  After the old knee was out,  I used the Dremel Carbide Rasp to grind down the surrounding fiberglass to get a good surface to lay new tape.

The old waterlogged plywood was a 1″ think single sheet.  Not knowing where Sabre got this size from, I had to laminate two 1/2″ thick marine plywood pieces together to form this new 1″ replacement.  The old knee was used a template to insure the chainplate’s bolt holes would be drilled and mounted at the same angle as the OEM Sabre set.

Old and new knees… This made a great template

 

The old waterlogged laminate

After cutting out the new plywood, I used thinned epoxy to wick into the woods end grain.  Two more paintings of straight West System epoxy was enough to encapsulate the ends and prevent the water issue happening again.

Thinned Epoxy going on the laminated plywood. Do you like my fancy sawhorse?

I mixed up a large batch of epoxy thickened with colloidal silica for rounded fillets, and started the process of putting the boat back together.  Two layers of 1708 biaxial fiberglass tape went up and I was done for the weekend.  This stuff needed to set-up before I could start layering on the 22oz cloth.

Fillets of colloidal silica

1708 Biaxial cloth

 

I sanded and washed away the amine blush from the prior weekend and layered on 4 new rows of 22oz 1708 cloth.  The fiberglass cloth extended 12″ either side of the hull and wrapped the knee fully encapsulating the plywood.  After drilling the holes for the chain plate (potting those with epoxy), I measured a thickness of 3/16 of fiberglass on either side of the wood.

I used Interlux Bilgekote in white to paint the entire lazzerate…. it looks awesome!  Unfortunately, in the hurry to put the boat back in the water, I forgot to take photos of this masterpiece.  I’ll update with these photos when I get the chance.

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