I got an old double canoe that had a big split in the white grp bottom. I've managed to fix the split with fibreglass and resin so the white hull is watertight again. I took the flaky paint blue top deck off by undoing loads of copper wires twisted together through small holes. Once the wires were removed the top and bottom came away easily. I'm looking at fittingt the top deck with outriggers, thats stabilisers each side so I can fish from the canoe. I found two plastic carpet centres that used to have a roll of carpet on them, thrown away and am using them as floats. The float bouyancy is created by using some long tgubular floats called "Noodles" in the seaside shops and sold for a quid each. They are closed cell foam and ideal for the floats.
I'm shaping some oak to match the top deck profile and connecting the floats to the end of the oak outriggers. There will be two, one front and one back.
I've added bouyancy to the canow by gluing in closed cell foam blocks and I've checked the in built bouyanct tanks front and back and they seem watertight. I was thinking of putting a circular cap on them for inspection purposes.