Wood to GRP Repairs

[Athene V30]

Whilst crossing the Dover Straits in my 21' Cox (Sailing boat) I fell off a wave, heard a crack and saw the join between the bulkhead about 18" forward of the mast and the deck head part company. Going to windward the deck now lifts up to 2" above the bulkhead, but returns when not on the wind.

The bulkhead is plywood, the deck head GRP. When I get her ashore in a few weeks and take the mast down (the inner shrouds went very slack) is it simply a case of gluing it back together and covering the joins with GRP tape and epoxy resin or should I get the boatyard to have a look and take out a second mortgage?

Thanks in anticipation!

 

[oldsaltoz]

G’day Peter,
If you re glass the bulkhead to the deck, the forces will be transferred to it, risking deck failure. Have you any clue as to what may have caused the failure? Apart from falling off the wave that is. Has the bulkhead been crushed near the top; is the forestay too slack or backstay too tight, have you got a lot of rake in the mast, is the foot of the mast corroded such that the load has shifted, causing the deck to deflect, has the compression post packer top or bottom moved at all.
Slack lowers should not cause this type of failure, as the cap shrouds would be taking most of the load and driving the mast down.
In any event, you should consider placing a packing timber between the bulkhead and the deck. If you make it a snug fit and a bit thinner that the bulkhead, the fibreglass and epoxy resin used will fill the undercut, add more tape to cover this fillet and run down onto the bulkhead for a strong finish. This packer should reduce the loading on the deck.
Some advice from your local yard would not be a bad idea, also contact the manufacturers to see how many others have had the same trouble and was done to rectify the situation.
Good luck, I hope this helps.

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[snowleopard]

OK for a time...

but laying polyester onto wood will fail in time as the resin is not a glue and damp will cause the bond to fail. possible answers are (a) a mechanical bond e.g. through-bolting or cutting holes through the ply and threading glass fibres through or (b) using epoxy which will stick to grp and wood as long as you abrade and de-grease with acetone. use woven roving type glass with the strands crossing the join at 45 degrees so it will take the sharp bend.