Re-installing the shaft coupling

[dlochner]

The article posted earlier is by Steve D'Antonio a well respected and knowledgeable marine professional and is published in Professional Boatbuilder. His advice is to insert the shaft into the coupling dry, no lubricants. As I mentioned earlier, it is the friction between the shaft and the coupling that is important, anything that reduces friction in the connection will make the energy transfer less efficient. Also mentioned earlier was the effect of shifting between forward and reverse, with a lubricant any small play in the connection will be magnified and induce wear on the shaft and key.

As for allowing the shaft and coupling corrode together, well that's a bad idea. Sooner or later all shafts have to be removed from the coupling for various reasons. Allowing them to corrode just makes the job harder and corrosion never made a metal stronger. To prevent or reduce corrosion spray the flange with a corrosion inhibitor after the flange is reattached to the transmission. This will prevent corrosion on the flange and make future service much easier.

If you are unfamiliar with Professional Boatbuilder, check their website, it is an excellent publication with valuable information by industry leaders. I've been a subscriber for decades.

Also check out Steve D'Antonio's website. Many of his articles published in Pro Boat, Cruising World, and other publications are available on his site. He does publish a monthly newsletter with articles on boating issues. He also publishes his work schedule which includes frequent trips to the Far East to oversee boat builds and boat surveys all over the world. I think he spends a lot of time in airports.

 

[American_Mainsail]

The article posted earlier is by Steve D'Antonio a well respected and knowledgeable marine professional and is published in Professional Boatbuilder. His advice is to insert the shaft into the coupling dry, no lubricants. As I mentioned earlier, it is the friction between the shaft and the coupling that is important, anything that reduces friction in the connection will make the energy transfer less efficient. Also mentioned earlier was the effect of shifting between forward and reverse, with a lubricant any small play in the connection will be magnified and induce wear on the shaft and key.

As for allowing the shaft and coupling corrode together, well that's a bad idea. Sooner or later all shafts have to be removed from the coupling for various reasons. Allowing them to corrode just makes the job harder and corrosion never made a metal stronger. To prevent or reduce corrosion spray the flange with a corrosion inhibitor after the flange is reattached to the transmission. This will prevent corrosion on the flange and make future service much easier.

If you are unfamiliar with Professional Boatbuilder, check their website, it is an excellent publication with valuable information by industry leaders. I've been a subscriber for decades.

Also check out Steve D'Antonio's website. Many of his articles published in Pro Boat, Cruising World, and other publications are available on his site. He does publish a monthly newsletter with articles on boating issues. He also publishes his work schedule which includes frequent trips to the Far East to oversee boat builds and boat surveys all over the world. I think he spends a lot of time in airports.

Thanks for chiming in, Dave. I agree with most of what you're saying here. I am a big fan of Steve D'Antonio's work and visit his site often.

As for allowing the coupling and shaft to corrode together, I don't want what I'm suggesting to be taken out of context too much. The interface between the coupling and the shaft is generally going to seize together if it's put together without anti-seize. The flange is usually made out of some kind of mild steel and the shaft is probably/usually either 316 stainless or a duplex stainless. In the humid, salty environment these live in, there's going to be some level of seizing of those parts together - which is what I'm suggesting it is that you want.

I'm not suggesting that you let the flange turn into a rust pile. I spray the outside of the connection with Fluid Film (I'm a huge fan of that stuff) to inhibit corrosion on the outer surfaces.

 

[Straycat22296]

Post Update:
I am adding information that I should have given on the first post.
I have a 1” shaft that is unfortunately bronze(?). It was equiped this way new.
Approximately 2 years ago I removed the shaft flange using a coupling puller purchased through Catalina Direct. It took me about 10 hours total time to get it off due to stripped nuts and bolts and limited working space. I used several types of recommended sprays weeks in advance.
I am now thinking of adding a no-drip stuffing box but will need to remove the shaft coupling again to do this work. I am hoping that I will not have the same experience if I decide to do it.
Due to the possible future maintenance that may be needed for the new stuffing box, I do not want to spend another hellish 10 hours every time removing the coupling. This is why I am asking the question.
I have worked on my own pleasure craft and commercial vessels for about 45 years, so my skills are not limited but I have never had to address this issue before.

Thank you for your advice.

 

[American_Mainsail]

Post Update:
I am adding information that I should have given on the first post.
I have a 1” shaft that is unfortunately bronze(?). It was equiped this way new.
Approximately 2 years ago I removed the shaft flange using a coupling puller purchased through Catalina Direct. It took me about 10 hours total time to get it off due to stripped nuts and bolts and limited working space. I used several types of recommended sprays weeks in advance.
I am now thinking of adding a no-drip stuffing box but will need to remove the shaft coupling again to do this work. I am hoping that I will not have the same experience if I decide to do it.
Due to the possible future maintenance that may be needed for the new stuffing box, I do not want to spend another hellish 10 hours every time removing the coupling. This is why I am asking the question.
I have worked on my own pleasure craft and commercial vessels for about 45 years, so my skills are not limited but I have never had to address this issue before.

Thank you for your advice.

Sorry to hear about how difficult it was to get your flange off. I am not familiar with bronze prop shafts, so I don't know if that's contributing to your problem. I think we've thoroughly debated the merits of anti-seize on the connection, so I think you have all the info you need to make the right decision for yourself. One thought I'm having is maybe that connection is machined too tightly. They're a finicky system. After a long time without coming off, these tend to get very stuck. I've heard of people having to cut them off at times.

I have used the whole "socket wedged between the flanges and longer bolts" trick to pop off my flange using the transmission to press against. I thought this was kind of a redneck trick that risks breaking something, but I saw Nigel Calder recommending the trick in his book when I was looking at resources on this subject yesterday. Maybe with limited space that trick would serve you better than a puller.

I mentioned Sigmadrive earlier. It's a great product that solves these issues associated with traditional couplings. It's spendy - mine was a boat buck after purchasing the adapter plate that my transmission needed. There's nothing in it for me, I'm just passing on my experience.

 

[dlochner]

There are pros and cons to the dripless seals. I've had PSS Shaft seals on 2 boats. I replaced the original bronze stuffing box on one boat with a PSS because it was difficult to access the stuffing box which needs annual maintenance. The PSS seals do need maintenance every 6 or 7 years, the bellows has to be replaced, which necessitates removing the flange. If my current boat had come with a stuffing box, I would not have replaced it because it is in a very easy place to access. The big con on the PSS is the failure mode. If the bellows breaks, you're in a heap of trouble as water will pour in. Replacing the bellows periodically is necessary.

If your shaft is bronze and you are investing in a new seal, consider just cutting the shaft to remove it. There is a high probability of wear in the stuffing box area and in the cutless bearing area.

Finally, use a split coupling. The builder's don't use them because they will add $30 to $40 to the cost of the boat and they won't recoup the costs.

 

[Ralph Johnstone]

I have a 1” shaft that is unfortunately bronze(?).

A bronze shaft is a bugger to work on. I helped a friend to repack the gland on a bronze shaft and it was a thankless job indeed. Trying to clean the shaft where the new packing sits while being installed was frustrating beyond words.

If your shaft is bronze and you are investing in a new seal, consider just cutting the shaft to remove it.

......................... and then replace with a SS shaft of Aquamet 22 or similar metallurgy. Once you see how the shaft stands up to corrosion, you will immediately forget the price. Just ignore the credit card charges each month.

There are several other things you can do to ensure the shaft comes right off for that first bellows replacement : first is the liberal use of Fluid Film as previously mentioned by @American_Mainsail. This shows mine after a packing job when the boat was about 15 years old.

I give it a cleaning every other year if I'm bored. A good soaking of FF where the hub meets the shaft ensures no water gets between the shaft and hub. The packing at that time was seven years old and it didn't require a re-pack as it was still soft and pliable. Shooting for a life span of ten years this time. And that brings up the packing material. It's Western Pacific Trading teflon impregnated flax packing. You will likely have a new shaft with a mirror polished surface so you will be able to run your gland dry. But only if you start with a mirror polish.

I can heat the naysayers choking on their libations right now, here's the instructions from the manufacturer .................

TYPES OF SHAFT PACKING, Wester Pacific Trading

Western Pacific Trading in addition to their wide range of marine maintenance products also is the official supplier of Ferro Pads and related products

www.wptinc.net

They convinced me and I never looked back. I wrote this a number of years ago to piss off all of the purists :

Do We Really Need to Leak .............

............. yes, for good health, about four to five times a day is good. However, for a number of years I have been chiming in here on packing glands leaking and the fact I have run mine bone dry almost from the day I bought the boat new in late 1998 as a '99 model H310. As mentioned in...

forums.sailboatowners.com

Unfortunately I see the posting is now cut short. It ran for pages with pro's, cons, and even a few comments containing promises of disfigurement (on me). The packing keeps everything pretty dry and dusty back there.

Due to the possible future maintenance that may be needed for the new stuffing box, I do not want to spend another hellish 10 hours every time removing the coupling. This is why I am asking the question.

Lastly, I could recommend coating the shaft and hub interior (where they contact) with anti-seize but I do not want to appear biased .

 

[American_Mainsail]

I'm with you here 100%, Ralph. The Teflon packing material is really good stuff. You can put it on tight enough to barely drip, but it's still just as robust as a dripless system and without all of the downfalls.

The Fluid Film keeps everything beautiful - nice looking gear you've got there. It washes up easily too.

I undercoat my car and truck with it every winter.

 

[Ralph Johnstone]

You can put it on tight enough to barely drip,

Ah, but do you ever run it with "no drips?" Keep checking it with your hand for temperature as you tighten it 1/2 of a flat every hour or so.

That SS shaft is a fairly good conductor of heat (the Cr interferes with conduction) into the cold, cold ocean. The heat is being created on the SS surface so not too much distance to travel before it sees that relatively large shaft cross section to conduct the heat away. Using an IR gun, I always see the highest temperature on the hub and then it drops as it hits the gland nut :

 

[CYQK]

+1 for anti-seize

 

[rgranger]

This thread seems like a good candidate for the sticky posts archive. What say you @Dave

 

[Ralph Johnstone]

This thread seems like a good candidate for the sticky posts archive.

But, we never did resolve the "Great Anti-Seize Debate." IMHO, there is only one scientific way to decide this debate ....................

​

................... which is really about the same as we've been doing so far.

 

[American_Mainsail]

I think we beat it to death. I don't know if there's any truly one "right" answer to discussions like this.

 

[Ralph Johnstone]

I think we beat it to death.

I think "shooting it to death at 20 paces" has the clearer ring of finality.

 

[BigEasy]

I don't have a problem with straight/solid couplings, just keep it free of corrosion & it should separate from the shaft reasonably well with the use of a proper puller. I usually apply a bit of antisieze on the key & keyway only. Split couplers are OK but not a necessity. Have you ever seen a split propeller hub, split harmonic balancer or flywheel etc.? Point is, that if the coupler is maintained, it shouldn't be so arduous to remove.

 

[Justin_NSA]

tomayto, tomahto. Stick a fork in it, this conversation is done! Folks are going to do as they please.