Propeller Shaft Tube

[Matt sachs]

Mine was rusted out, so I cut it out and tossed it in the scrap pile. It was just a simple steel tube with what looked like a zink tube pressed inside, and that was lined with a rubber tube. The inside end had a stuffing box. This seems kinda low tech to me.
I dont want to start another "what is the best way to do _____" thread, but I need learn all I can about this before I proceed.

Opinions wanted (concerning the best way to do this part of the refit)

[capngeo]

What material is your hull made of?

[Matt sachs]

Oh, sorry. Its a steel hull.

[capngeo]

I'd weld a pipe of the right diameter, and clamp a bronze stuffing box via the correct rubber shaft coupling hose.

[Matt sachs]

Thanks for the tip.

[skipmac]

You can get the bronze stuffing box and the rubber hose to attach it from Buck Algonquin. Buck Algonquin...Quality Marine Hardware Since 1955 Also new cutlass bearings.

They also make bronze shaft logs (the pipe that the prop shaft goes through into the hull) but in your case with a steel hull I think steel shaft log makes sense.

[Matt sachs]

So.... I guess they are pretty simple. A brass cutlass bushing with rubber liner, the log itself will have sea water in it, the seal on the inside is either a dripless, or a dripper. Is that all there is to it? My machining back ground makes me want to put in seals and bearings and grease fittings and.....LOL thanks again for the tips

[skipmac]

Originally Posted by Matt sachs

So.... I guess they are pretty simple. A brass cutlass bushing with rubber liner, the log itself will have sea water in it, the seal on the inside is either a dripless, or a dripper. Is that all there is to it?

Yep. That's pretty much it.

[Boracay]

I'd be in favour of replacing the stern tube with the thickest steel tubing that you can find that will fit.

Boracay has a cutless rubber bearing in a steel strut, so I'd expect that any competent machinist could make something for you. I be in favour of something with lots of metal thickness welded on.

The bearing on Boracay is held in place with a set screw - it was probably a tight fit to start with.

Welding of thick metal is a bit of an art, so a professional welder may be worth the money.

Don't forget to leave enough room for a decent size anode, with maybe a couple welded to the hull nearby.

Finish it off with a quality stern gland (some may need water supply through the stern tube) and, apart from the occasional check, you may be able to forget all about it.

[lorenzo b]

My stuffing box has a grease fitting and I grease it regularly. Not an add-on, built right into the box.

[stillbuilding]

There is am up-market version for steel boats which includes a complete sterntube and stern glands and seals which is inserted inside an outer steel tube and held in place by welding at each end and epoxy gel in between. Vetus catalogue has one version. High class engineers make others - Poseidon/Pegasus people do this also. Or you can just use a thick tube and keep anti of grease in it like the rest of us!

[Matt sachs]

Thanks guys this has been very helpfull.

[sdowney717]

Use GFO marine packing, no drips needed, runs cool

http://www.gfopacking.com/

IMO, any other dripless configuration is obsolete and a pain to keep right.
This packing just goes into a standard packing gland and is smooth and silky feeling.