I saw yard today, it really looks like they can’t pull me out and get back me in the water at a time scale to suit. Ho hum. Wiebe asked if I would be on board during the day; nope I said I’ve done just about everything. Visited ship and ran up engine, straight towards red! This after she has behaved all winter during periodical engine runs and after much work… S**t. OK, have to sort it out so got my pain head on and stripped heat exchanger, exhaust and manifold, back to house to clean up. Hello, I can hear something rattling in heat exchanger. Poking, torch, hammer and screwdriver to break up the lump and get it out resulted in the below image.
I’ve ordered some acid and will treat the heat exchanger to a descale whilst it’s off. Checked thermostat (again) perfect. I’ll build it back up again as soon as acid arrives, clean electric impeller (again, it picks up metal particles from primary cooling water and this can degrade capacity). Then raw water pump (again). Buy a boat and work to death. Fun tho!