Repairs

VulcanSpirit
Richard & Alison Brunstrom
Sun 16 Sep 2012 18:11
One of the banes of a seafaring life is the constant need to repair broken equipment. The maritime environment is a harsh one to be sure, and we have lots of complicated gear on board much of which seems to be poorly designed, under-engineered, badly sited or all three together. The result is a lot of time spent fixing things which have stopped operating, usually at an inconvenient time. All our acquaintances have the same experience - a huge amount of time must necessarily be spent on repairs and maintenance, every moment of it begrudged unless you regard DIY engineering as an enjoyable pastime in its own right (which I most certainly do not).
We've actually had a fairly easy time recently, but here in Tonga a couple of things have failed. The weather here has been truly horrible (never let anyone persuade you to spend money on a holiday in Tonga!!) and our autopilot control head situated on the steering pedestal got very comprehensively soaked by rain in a tropical downpour. Despite being allegedly waterproof it has managed to absorb some water and stopped, potentially a diastrous state of affairs - we have never forgotten our 1500 miles of handsteering, 4 hours on and four hours off, from the Caribbean to New England, and never will. So this failure led to a couple of hours dismantling the pedestal to get at the control head, and a couple of days trying to dry it out, so far unsuccessfully. This is most unwelcome and inconvenient, but luckily unlike most boats we have another control head inside the boat, so we are still mobile and will be able to get some sleep on passage.
I also found a salt water leak from our generator. I was dreading it being from the salt water pump again, but examination (requiring lying on top of the running generator wearing a headtorch and using a mirror on a stick) revealed that astonishingly the end plate on the heat exchanger had fractured. The generator is fresh water cooled like a car engine, but unlike a car which has a radiator to cool the fresh water, a marine generator uses sea water in a heat exchanger to dissipate the heat from the fresh water. Fresh water runs through narrow tubes in a salt water jacket. the jacket is a large tube, each end od which is sealed by an O-ring, a rubber gasket and a metal end plate. I have spare O-rings and gaskets, but had never dreamt that it would be possible for a flat bronze plate under little pressure to crack, ever. So I have no spare. But for some reason one has cracked; the other is perfect. Of course the one that chose to go was out of sight and difficult to reach. 
So with no spares, and the generator essential, it was necessary to jury-rig. Here is my attemp under construction on the galley worksurface:
 
  
 
I have to use the smooth Corian worksurface to get a purchase for the vice, so the spoon is there to keep sharp tools from scratching it. I have cut a circle out of some rigid marineply. A hole will shortly be drilled in the centre for the fixing bolt with a variety of washers and some sealant to hold it all in place. Amazingly it works, and we have power again. We will get to Fiji and then I'll have to get some parts sent up from NZ for a proper repair.