shaft log with dripless seals for centurion boat

Once the sharp circular edge at the tip is flattened, it won’t properly bite.

The two holes in the rotor call for four setscrews-two against the shaft and two to lock the bottom screws in place. Larger shafts or troublesome seals require a bit more. Mark this neutral position with tape or a Sharpie and then push the rotor farther against the springiness of the bellows-for shafts smaller than 1½ inches, an extra three quarters of an inch typically develops the right pressure. Now replace both O-rings inside the bore of the rotor, lubricate them with dish soap-never grease-and slide it back onto the shaft until it touches the carbon seal. If you must also lap the carbon seal, go easy it’s much softer than stainless. With the boat out of the water, remove the shaft from the transmission coupling (you may have to remove the prop as well in order to slide the shaft far enough astern to get adequate clearance), slide the rotor off, and work it in a figure-eight motion on 600-grit sandpaper-a piece of glass ensures that sandpaper lays perfectly flat. Worst case, you may have to lap a badly neglected stainless-steel rotor. If they don’t, fold a sheet of 600-grit wet sandpaper in half, slip it between the carbon and stainless faces, and pull the sandpaper around the circumference of the shaft a few times. Technically, the surfaces should self-polish with use. If either the carbon face or stainless rotor loses its polish, your seal will leak, and once leaking, the steady drip of seawater will leave residue behind, worsening the leak. It’s simply pressed against a stationary ultra-smooth carbon surface by the bellows that attaches to your shaft log. The stainless steel rotor on face seals like PYI’s Packless Shaft Seal ( rotates with the shaft.

Shaft log with dripless seals for centurion boat