That was the view from inside the boat this morning. A bit jarring, considering we'd been keenly looking forward to the fall sailing all this year. However, events dictated that we pull the boat. NOW.
We had been observing a patina develop on the brand-new through hull for the galley sink, which was a bit concerning to us. Then we spotted the far more worrisome image below.
That's our propellor shaft. With something on it that looked like -- and felt like -- serious corrosion.
???
My own big boat sailing experience from my youth is utterly devoid of this knowledge; our Tylercraft 26 had no through hulls below the waterline and our motor was a 10 horsepower outboard that we pulled from the water after every use, so the cause and effect of marine corrosion like this is completely foreign to me. Cindy dove into the cruising forums and quickly determined we probably had galvanic corrosion taking place. And given how quickly it can eat up metals on a boat, we needed to address the issue pronto. So last Monday I called Jake with the service crew at the marina and scheduled Shearwater to be put on the hard Tuesday morning.
Our worst fear was that the prop shaft would have to be completely replaced and would cost beaucoup bucks. At a minimum. Our dockmate, Jason, checked on Shearwater after she was pulled and confirmed part of our fears with the following text:
She is high and dry and your zinc is 99.9% gone. The paint is still on, but it's not adhering very well.Oh, man... That's all either of us could think about for the rest of the week.
Cindy decided to stay home and try killing her lingering cold with lots of sleep, liquids and lots of sleep. Did I mention lots of sleep? So I proceeded down to the boat on my own Friday night, arriving too late to give everything a thorough check due to the lack of decent light. This morning I popped out of the cabin bright and early and observed the following vista...
Right. Enough dilly-dallying around -- there's work to be done.
Sure enough, our zinc is GONE. As in, the only thing left is the screw. Wow.
I gave the rest of the bottom of the hull a careful inspection. Per Jason's observation, the bottom paint is indeed shot, with lots of shallow craters, barnacles and chunks of delamination from the hull.
But the through hull fittings all looked good, and none of them appeared to have the dreaded pink color indicating that they were being eaten up by galvanic corrosion. Note in the image below that the bronze is really a warm bronze color; the camera has a rough time with color correcting accurately due to all the surrounding blue.
And below is what the propellor shaft really looked like after the service crew carefully cleaned it. No corrosion after all. What we had spotted earlier and thought was corrosion was simply scale build up, and it could be scraped off with a knife blade.
The close-up shows no micro pitting.
Whew! The relief was palpable... No shaft or engine damage after all. All we need now is to have a new zinc installed, the packing nut reassembled and she's ready to be put back in the water -- ready for the rest of the fall sailing season.
The rest of the morning I spent on checking the interior side of all the through hulls. To my eye, everything looks normal, like it should.
Below is the rudder assembly at the stern of the boat.
Below is the through hull for the sink in the head.
Below is the through hull for the depth sounder in the bow, just ahead of the keel.
And below is the through hull for the air conditioner. As you can see, everything looks good and there doesn't appear to be any adverse corrosion on any of them.
I'm set for the rest of the weekend. I have plenty to read, work on, photograph and otherwise keep me occupied for the rest of the time I'm down here.
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