Shaft Replacement or…

[JimC]

Hi Folks

We have Lily D up on the ways and have pulled the prop shaft out as we had to have the cutlass bearings replaced and the shaft had not been out for inspection for 15 years or likely more.
The inconel shaft is in decent shape, but there is wear at the two cutlass bearing locations and at the stuffing box, enough that the new cutlass bearings will not be tight to the shaft.
We cruise about 2000 nm each summer up the BC mid coast area and want the drive system in top shape, repair facilities are few and far between, so are thinking we should replace the shaft.
Another possibility might be to reverse the shaft end for end to have the cutlass bearings on unworn parts of the shaft.
I am not sure if this is possible, or if it is possible, if it is a good idea?
Any thoughts or comments would be appreciated
The shaft is 1 3/4 in dia. and we run a 4-71 with 130 hp

 

[Insequent]

The ends of the shaft are likely different with respect to having a keyway and possibly a taper at the prop end. If so the it would not be simple to end-for-end the shaft.

You may be able to get the worn areas on the shaft repaired. I think it starts with plasma arc welding to fill the area, followed by machining back to correct diameter.

 

[RT Firefly]

Greetings,
Mr. JC. The late, great Mr. FF (Fast Fred) used to recommend some sort of sleeve to clad the worn part of the shaft. It is a real repair and not a band-aid as one might assume. Of course, my non existent memory can't recall the name or brand(s). Perhaps another TF member can provide that information.

 

[twistedtree]

With a 1-3/4" shaft, I'd probably just replace it and move on. That's what shaft people and boat builders know how to do in their sleep, so higher probability that they will actually do it, and do it in a timely manner.


Any sort of shaft repair is getting into more specialist work. Unless you already know someone who is a known-expert, I think there are many, many ways for the project to skip the rails, all on your time and your expense.

 

[C lectric]

There is a company in VANCOUVER CALLED V.M. Dafoe on Powell St. Link below.

https://vmdafoe.com/duramax-marine/


Email and/or phone them. They are a long standing, expert shaft machine shop specializing in marine work.
It may be possible to repair your shaft. They should KNOW.
Inconel is not a cheap material and is virtually corrosion proof but of course not wear proof. THey may be able to do as mentioned above, spray weld and then machine the welded area or suggest a good alternative.
But contact them.

I have no knowledge about what is available in Prince Rupert but have you looked there? I know the fishing industry has waned in P.R. but there is other industry there so maybe a good marine shafting shop there also.
Some of the larger repair yards for the fishing boats could do this kind of work which is what Celtic Shipyard did for me many years ago. Celtic is gone now for 20+ years.

If the shaft is not repairable then likely they will suggest SS replacement. My now 45 yr old boat has its SS original shaft. It was just in at Dafoe and I asked about a rough price for replacement and the guy looked at the shaft and simply said " you don't need a new shaft". They tweaked it for a slight bend which is why it was in there. Keep SS of the right alloy anoded [zinced] properly and it too should last and give good service if that is the way you go.

Just my thoughts.

 

[RT Firefly]

Greetings,
Mr. JC. It was something like this...https://www.globaloring.com/shaft-repair-sleeves/ or this... https://www.mcmaster.com/shaft-repair-sleeves/

 

[JimC]

Shaft replacement

Hi Folks
Thanks for the prompt help and suggestions
Insequent , thanks for pointing out that the prop end has a machined taper, I missed that.
RT Firely, thanks for the sleeve suggestion, haven’t managed to track that down for anything but big ship’s shafts.
Twisted Tree, I suspect you are right about replacement being the simplest and safest option, Lily D is hauled out in Sidney BC and unless there is someone with the facilities and knowledge there, the shaft would likely have to be shipped to Vancouver to VM Dafoe Machine for weld buildup and machining. To further complicate matters, I have no proof that the old shaft is inconel , that info is only based on the survey when we purchased the boat.
C lectric , thanks for the info on VM Dafoe, that is where the yard has gone to for a quote on a new shaft and I will request that they ask about the possibility of repair, but can also see that shipping and buildup/machining and reshipping may spiral past the cost of a new shaft and may also lengthen the haulout time which adds up quickly and is tough on wooden hulls

 

[Jeff F]

I went through a similar process last year and had a new shaft made. Mine is 2" and about 11 ft long. Cost was about $3600 IIRC. Something like $250/ft material plus machining.

Restorative work makes sense on larger shafts, but for smaller ones you can order them on the internet and do a swap. It's an easy choice.

 

[koliver]

You don't say how deep the scoring "wear" is.
I had new cutlesses a few years ago. My yard guy pointed out some scoring on my shaft, but cautioned me about getting excited about it. his experience (orders of magnitude above my own) led him to say that this amount of scoring would be expected in a boat that was 40 odd years old, but that it would go another 40 or so years before it was a problem.

 

[JimC]

The pictures that the yard sent show some scoring but also a visible reduction in diameter. The shipwright said he could put the old shaft back in but there would be significant slop even with new cutlass bearings and recommended replacement. Dafoe has quoted $2900 for a new Aquimet 22 shaft so that looks like the best option for cost and schedule. The old shaft is likely original and Lily D is pushing 60

 

[jimdavi]

I’d replace it. I would also add a new transmission/shaft coupler.

 

[jleonard]

I’d replace it. I would also add a new transmission/shaft coupler.

And have the shaft maker face off the surface of the coupler while it's mounted to the shaft.
Whether you go with a new coupler or not.

 

[PM]

There is a specialized process called "Spray Welding". Investigate it. It might be a process which could help you.

pete

 

[garbler]

Pete is correct. Spray welding tail shafts is quite common on commercial vessels and has been for years. Lloyd’s specs for propeller shafting is pretty tough but they will accept metal or thermal sprayed shaft restoration depending on the depth and nature of the problem.

Rick

 

[JimC]

Shaft Replacement

Thanks for all the assistance on the shaft question
We are having a new shaft fabricated, the costs of buildup weld and machining were estimated to equal or exceed the cost of the new shaft and then we would still have had an old shaft.
The coupling is in good shape and the parts have been sent to the fabricator to fit to the new shaft.
It should be complete and shipped about mid week.

 

[jimdavi]

I would replace the coupler if able and new bolts/hardware.

 

[Choices]

I would replace the coupler and make it push the shaft back 3-4". If you have room. Then I might add a shaft saver.

If there is room at the prop end, you are good to go. If not, shorten and taper it.

You just need to get a new wear service.

 

[Comodave]

With a drive saver you can’t do a proper alignment. We had them in our last boat and took them out and had custom spacers made to fill the gap. Then we could do a proper alignment.

 

[Crux]

Consider a 'clamp fit' coupler....then you're not just dependent on setscrews to hold the shaft in reverse....take a look at Walter Couplers.....