When we did the sea trial, the shaft seal leaked.
We have a PSS shaft seal, which is a purely mechanical seal that doesn’t require any sort of packing as in a traditional packing gland. It consists of a stainless collar that is pressed against a graphite fitting. The idea is that it’s slippery, sealed, and doesn’t heat up. Here’s a diagram from the excellent “How Boat Things Work” by Wing.
On the sea trial the shaft seal leaked slightly at an idle, and more so as the engine was brought up to operating speed. During the xmas work trip Jon tackled this job. Loosen the set screws, slide the collar up, figure out how to reach in there to clean it, push the collar back down, tighten, easy. The only tricky thing is that after many years, the rubber bellows loses it’s elasticity, so we were clueless as to how tight was tight enough. We just pushed the collar as tight as we could and locked it down. When we ran the boat in february, it didn’t leak.
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