Prop Shaft Half Installed

I cleaned up the old (probably the 35 year-old original) stuffing box on the wire wheel. Although it’s scared, it still works. The threads are still good, and it assembles/disassembles easily. Also, it appears that the new flax/stuffing I used two years ago is virtually still new.

Pre-clean up. Pretty gnarly.

Clean and reassembled.

Fuzzy photo of the packing. Four rings of packing material. . . looks nearly new.

Mounted on a new length of Buck-Algonquin stuffing box hose.

I am so impressed with any boat part I’ve used that was bronze. This stuffing box would have been a mass of corrosion beyond renewal if it had been stainless.

When replacing a stuffing box hose, the Buck-Algonquin 5-ply non-wire-reenforced hose is the stuff to use. Lots of folks use reenforced exhaust hose, but there are problems with it. First of all, it will torque (twist) as the prop shaft turns – meaning it’s pretty flexible, after all, even though it’s wire-reenforced. Second, the wire itself is problematic. At the ends where it is cut to length, water is allowed to enter along the length of the wire. In salt water, this eventually results in rust, which compromises the integrity of the hose. The Buck-Algonquin hose (available at Jamestown Distributors), having several additional plies of material, is more rigid and resists twisting under torque, and there is no internal wire.

I spent a few minutes polishing the new shaft with a wire wheel, and similarly polished the inside of shaft coupling. Then I liberally applied water-proof grease to the key, keyways, shaft and coupling. I test-assembled the shaft and coupling to ensure they would go together without a lot of force (they did). When assembling the shaft and coupling at the boat, there is no other way to fit the pieces together besides using the transmission end of the coupling as a back-stop, so the components have to fit together as easily- with as little force -as possible. Banging away on the shaft from outside the boat, using the transmission/coupling to absorb the shock, is a quick route to transmission failure. While assembling the shaft, I positioned a block of wood between the two halves of the coupling, started the shaft into the coupling by hand, then climbed down outside the boat and gently tapped on the end of the prop shaft with a 5# hammer buffered with another block of wood to seat coupling and shaft. After 7-8 trips up and down the ladder to check the progress of the shaft into the coupling, I determined that the shaft and set screw dimple were exactly aligned. I cleaned the set screw threads and greased them well, then screwed it firmly into place.

But there was an unexpected misalignment between the coupling halves.

Wasn’t it aligned when I removed the old shaft? Well. . .  I honestly don’t remember. I know it was aligned two years ago – the result of an entire afternoon of labor. I did some reading though, sitting at the picnic table at the boat yard, and discovered that “experts” don’t attempt coupling alignment with the shaft log hose installed rigidly, or the stuffing box installed. Okay, that makes sense. Earlier, when I was installing the hose onto the stuffing box, I discovered that the hose would easily go off-center as I torqued the hose clamps. Undoubtedly, this is what happened when I got the hose/stuffing box/shaft log joined together. But by this time, I was ready to do something else. I had enough of crouching over the engine for one day. Tomorrow is soon enough to disassemble the shaft log stuff and address engine/coupling alignment.

My last item of the day was to install the prop on the shaft. I set the key into the keyway, slid the prop up the shaft, and turned the larger of the two nuts down onto it. After spinning on the smaller locking nut, I tightened the larger nut, then held it in place with a wrench and tightened the locking nut against it. I slid the split pin in place and spread the ends back on themselves.

Ready for antifouling. Might try liquified lanolin on it this year for antifouling.

We’ve had these toddler-sized chairs since our kids were tiny. They are perfect for working on projects that are close to the ground, cutting down the mileage on my back and knees.

• Buck Algonquin Stuffing Box Hose
• sailboat shaft coupling
• stuffing box
• stuffing box hose