now I know I said earlier that I was going to cut / scarf in some new bits ply...... but I decided against that for a couple of reasons.
1/
time restraints: after I'd cut the first bit I figured this was going to take ages and I wanted a simple solid quick fix, simply because I won't know what's going in there until I tear the decks off in the off season.... the rot may be far worse than I know about at the moment

2/
strength issue: scarfing in is the traditional method BUT it lacks some strength, there was also the problem of curving the ply to better suit the hull shape, that meant time being spent of pre-curving the replacement ply aswell as the scarfing.

So I decided to do something an old sailor from way back when taught me at a regatta when my old mozzie was damaged....
a hole from a another mozzie just after the morning race was fixed during lunch and I was back on the water for the afternoon races, although the fresh resin was covered by that trusty old best friend..... gaffa tape


cut a ply plate that's just a bit bigger than the hole

bang a staple right in the middle of the plate then remove the staple

thread a fine wire through the 2 holes left by the staple

coat the ply plate in resin and slip into the hole

slip in a short dowel and twitch the wire around it then twitch the dowel so it pulls the plate up against the hull

with the remaining resin add sawdust till its like play-dough in its consistency

trowel the mix into the 'cavity'

let it set..... sand back .... paint as required or if needed


now I've used this old trick many times over, even Jurassic Karp has a few dabs of this in in, specifically where the old stringer slots were.
Its as light as you want it to be, use balsa-wood / cedar / pine etc.
Want it a bit heavier then use harder woods or as I've found plywood itself saved from the band saw works a treat

the big advantage is the strength, all the fine chips of sawdust are not all spread out but mixed up and tightly compacted. It sets super fast and can be sanded easily, I laid it down on Sunday with 7day resin, it was sanded back Monday night, micro filled on Tuesday night and finished tonight.
The process could have been done far quicker had I used a rapid set resin, the whole job would have been done in less than ~4hours

As it stands now, I have structural strength WITH a ply backing plate, the repair can easily be finished off once the decks are removed ..... flap disk on the 4" grinder, "grind" off the ply backing plate, add resin and cloth.... all done


the dark patches are the sawdust/resin mix





happy with the end result, it smoothed out really well and the microballon filler made it a perfect flush finish

centreboard case's are next on the agenda.....