Finally it looks like the temperature will rise above 10C and stay there for a few days, so I can stop fiddling with small imperfections which are endless and get on with 'boat soup' and hope it will make the canoe waterproof.
The outwales had been broken at the stern, maybe from rot, having been stored upside down or maybe from an impact. I tried steaming the final original piece, to be scarphed to a 6" insert, also steamed. I used a plastic bag, of the kind books come in the post, so a bit tougher. It worked well but 30 minutes steaming, although it allowed the 1/2"x1/2"x6" pieces of oak to be bent between two formers, they didn't keep their bend, so I cut pieces to shape instead. It's hard work cutting oak without power tools.
So, the soup... as recommended, I got 500ml of Tung oil and 500ml of boiled linseed oil. I had a tin of varnish and plenty of white spirit (mineral spirit in the US/Canada?). There happened to be 300ml of varnish left in the tin, so that was my unit - 1 unit tung, 1 unit linseed, 1 unit varnish and 3 units white spirit = 1.8litres, which seems to be about right for a 14ft cedar strip. I've done the inside and the decks and wales and there's 600ml left, with just the smooth outside to do, when this lot has dried in three days.
As you can see from the photo, it turns the old wood quite dark, while the new wood shines out white. In the other photo, you can see the soup doing it's stuff and leaking into the untight joints.
