Propeller Shaft question

[Peter]

Hello All,
I'm into my dry land refit and am servicing the prop/shaft/stuffing box/coupling area of my Albin Vega 27.

She used to have the old 'Combi' reversing prop and was later converted to a Yanmar with conventional gear box, etc.

I have a question regarding the junction of the shaft tube and the stuffing box. A piece of rubber hose was used as a bushing to increase the tube size to match the stuffing box. Then a larger piece of hose (old one shown) is used to connect the two together. The rubber sleeve was pushed in flush and glued with the outer hose, and clamped in the usual manner. It did not leak in the year I used the boat.

Now that I'm re-assembling things, I'd like to know if this a proper way to make this connection, or is there a better way?

Thanks!

[Tim]

Since you're redoing things, I would first look for a stuffing box assembly that incorporates the proper diameters at each end: whatever your shaft size is at the nut end, and the outside diameter of your stern tube at the other end. This way, a new hose will properly secure to both the stuffing box and the stern tube.

There is a wide variety of sizes available to match most common setups. Sometimes, though, you can't find the proper size. I had this problem with Glissando, with my 1" shaft and small 1-3/8" OD stern tube. None of the available setups fit both ends, as typically smaller shafts are used with the smaller size stern tube. The prop shop eventually supplied me with a stuffing box for a 3/4" shaft (which typically has a hose meant for 1-3/8" OD stern tube) and bored out the shaft end to allow the 1" shaft to be inserted properly. This is another option for you--the slight custom modification.

What are the ODs of your shaft and stern tube?

The bushing situation that you had seems to work, as you say, but is less than ideal. It'd be nicer to replace the stuffing box without needing the bushing, as everything would be more secure in the end. Even though your setup worked, and even though if it failed you'd still probably end up with a small, manageable leak, it would still be superior to avoid this situation. There's always another way...sometimes, the better way is more work to complete, but it may be worth it at this juncture. I wouldn't trust the extra bushing in the long run--it just seems like it might add too much "softness" in the system, and/or make it difficult to keep tightly clamped and secured. A direct connection between hose and stern tube is going to be more secure in the long run.

The final option, if you're unable to find a stuffing box to fit properly, would be to remove the old stern tube and replace it with a diameter that matches up with traditional stuffing box sizes available. Removing and replacing a stern tube isn't as much work as you might think.

Here's how I replaced an old stern tube.

[Peter]

What are the ODs of your shaft and stern tube?

The shaft is 1" and the od of the tube is about 1.275" ...approx. (it was dark and freezing out there)

I like the idea of getting a better stuffing box. I can always re-size the hole as you did, and maybe machine the tube end to match the tube exactly.

Removing the stern tube scares me a bit as everything on this boat is built better than I can ever replace!

[Tim]

The shaft is 1" and the od of the tube is about 1.275" ...approx. (it was dark and freezing out there)

I like the idea of getting a better stuffing box. I can always re-size the hole as you did...

Wow...that's a very small OD for your stern tube (probably because it's bronze pipe, rather than fiberglass, and therefore has a much thinner wall). I doubt you'll be able to find a stock stuffing box that incorporates a 1" shaft and a stern tube as small as 1-1/4". You'll probably need to bore out the shaft hole.