This is one of the last big jobs to tackle. The problem I faced was that before I could get the tank painted I needed to do something about the interior. Twenty odd years ago I had put a Petseal tank sealer solution into it, but this had split and cracked. I didn't think pouring in more on top of it would be satisfactory and there was no way to completely remove the old stuff because of the limited access.
So I had no real choice but to cut it open. Before I did so I found a local boat repair man who specialises in fibreglass and gelcoat repairs. He's going to glass it back together for me and we'll find the best product for recoating the interior.
It was a dusty job but not too difficult to open it up. I cut in to it with a thin disc about half an inch from the edge then went round the curved tunnel with a hacksaw blade. Once open the old petseal came off in big pieces, only here and there was it well attached.