well me and my gran stuck the spine together today, we used the same carbon as the panels had, with a little reinforcement on the end bit of the join. to fill any gaps left by our dubious cutting yesterday, we used a mainly silica based bog to fill the gaps, then laminated each side. The process seems to have gone well, but we shall see how strong it is tommorrow. we are trying to help the curing along with some floodlights before we get a fan heater, pictures below