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My sailboat is a C&C 29, 1983. Yesterday I was swimming under it and noticed, I think for the first time, that there is a bronze, bullet-shaped collar on the prop shaft forward of the strut/bearing. This collar is free-spinning/sliding on the shaft and naturally rests on the strut due to gravity. The prop is a folding/racing prop, not sure if that is pertinent. What's the collar for and is it supposed to be free or is it supposed to be pinned to the shaft?

Also, the shaft didn't feel loose in the cutless bearing but it was easy to spin by hand. My memory is that they are typically hard to spin by hand, at least on the '68 ski boat I used to have. Is that a sign of a cutless bearing on it's way out or is that to be expected when it's in the water/lubricated?

Thanks,

Jeff

Give the shaft a good shake. If you can feel it move it is time to replace it. My buddies cutlass in his sailboat seems to have lasted 30 plus years. On my fishing boat they only lasted a couple of years but I was running in very nasty water a lot of the time. Are you sure the the collar is bronze? My first thought is it is a shaft zink that has come lose.

Fuzz wrote: ↑Fri Aug 07, 2020 12:53 pm Give the shaft a good shake. If you can feel it move it is time to replace it. My buddies cutlass in his sailboat seems to have lasted 30 plus years. On my fishing boat they only lasted a couple of years but I was running in very nasty water a lot of the time. Are you sure the the collar is bronze? My first thought is it is a shaft zink that has come lose.

Zinc! I didn't even think of that. It could be, I was looking at it through goggles underwater. I'll take another look and see if there is a zinc elsewhere on the shaft, otherwise, that could be it. I will say that if it is the zinc, it's untouched by galvanic corrosion, was not rough at all, maybe why zinc didn't occur to me.

The boat will be out of the water in another few weeks/month and I can tend to whatever so it's not a big deal, just made me scratch my head a bit.

It is good you are planning on hauling it soon. If the zinc is loose it is not doing its job and something else may be getting eat up. Look close at all the other under water gear. If any looks sort of pink it has been leaching the zinc out of it. When you pull the boat post pictures.

Fuzz wrote: ↑Fri Aug 07, 2020 12:53 pm My first thought is it is a shaft zink that has come lose.

Took another look and I'm sure this is correct. There was a set screw that we tightened. Here's what baffles me though: due to the style and the location, the only way to change it is by pulling the shaft! I had to pull the shaft on my ski boat once and it was a royal PITA, as I recall. The previous owner was a racing nut, hence the folding prop and probably this style of low drag anode. But that seems like a lot of hassle to pick up a 1/10 second around the buoys.

In any case, appears there is some movement with the shaft so I'm going to plan a swap on the cutlass this off-season, unsure if I'll tackle it myself or let the marina guy do it. The anode, as I said, appears perfect, which either means something else is being sacrificed or there's just not a lot of corrosion going on when the boat is on a mooring for 4 months a year in freshwater. I'm guessing/hoping it's the latter.

I'll check the other stuff when it's pulled. There's not a ton of other metallic gear underwater but I'll look for any pink, great tip.

Being in fresh water will make a difference with the corrosion. I think there are different anodes for fresh water. Maybe one of the guys who boats in fresh water will chip in. I will be surprised if you do not find the anode is spilt when you get it out of the water.

I looked online and see you have a fin keel boat. I saw a collar zinc ahead of the strut on them also so that is normal.
I have never had a strut hung shaft so it might be easier to change the cutlass for you but all of them I have done involved pulling the shaft. I will be helping a good friend change his cutlass this fall. The way his Downeaster is built we will be jacking up the engine and pulling the shaft out under the engine.

I missed that question.
Yes, it is a zinc anode. Those MUST be replaced regularly, they are sacrificial.
You don't have to pull the shaft.

To change the strut bearing, you must pull the shaft. I wouldn't bother unless you have vibrations.
On a boat that size, the shaft should turn by hand, it's normal.
I prefer solid bearings like Thordon.
A small portable press will help to install a bearing but I use a trick.
I buy some dry ice and put the bearing in it, It shrinks just a little bit but enough to push it in the strut with a large clamp.
I have used that trick many times.

jacquesmm wrote: ↑Sat Aug 08, 2020 2:38 pm
I wouldn't bother unless you have vibrations.
On a boat that size, the shaft should turn by hand, it's normal.

Since I got the boat, about 6 years ago, there has been a "vibration" at lower rpms, but once I get it up to about 2400, my normal operating rpm, it smoothed out completely, and that is still the case. I was led to understand that the vibration at lower rpm was due to resonant hull frequency. The pre-purchase inspection report indicated that the cutlass bearing was fine at the time of purchase. I've only gone through maybe 4 or 5 20 gallon tanks of diesel since I've owned it so there hasn't been a ton of engine use.

The vibration could be normal for your engine. Lots of small engines do that until they are up to speed.
My buddy can find no evidence that the cutlass has ever been changed in his forty year old boat. Yours could be the same. The good news if you do need to change it out you will likely not own it long enough to need to do it again.
When you put a new shaft zinc on it make sure it is a two part one that can be changed out easily.

Fuzz wrote: ↑Sun Aug 09, 2020 2:33 pm The vibration could be normal for your engine. Lots of small engines do that until they are up to speed.
My buddy can find no evidence that the cutlass has ever been changed in his forty year old boat. Yours could be the same. The good news if you do need to change it out you will likely not own it long enough to need to do it again.
When you put a new shaft zinc on it make sure it is a two part one that can be changed out easily.

Appreciate the input Fuzz, that's reassuring.

I'll have my marina guy give his opinion on the cutlass once it's on the hard and he can shake it. He maintains a number of similar boats at the marina and doesnt recommend work if its not needed.

Occurs to me that I can probably just add a 2 piece anode if/when its needed and either leave the existing or just cut it off. The one-piece on there looks perfect right now.

Finally got a chance to see this thing without being underwater. Definitely not a zinc. There is no zinc, should not be an issue in freshwater on a mooring.

My marina guy is guessing it's a line cutter that has lost its blade. I think it's just a drag reducer and is supposed to go just ahead of the strut.

Shaft movement not warranting a cutlass replacement, apparently, so I'm not gonna worry about it. Weather was too crappy to put my mooring ball on so splash postponed till next saturday.

Here's the whole sh'bang:

I am with you, that is to reduce drag. Someone was trying to get the boat to go as fast as possible. If it were a line cutter it would not work there, too far from the prop. Is there screw holes on the back of it to bolt something to it?
Be very happy you do not need to change the cuttless. It would not be too bad with your set up but still a pain. I am in the middle of helping my buddy change his. It is a real pain in the butt To get the shaft out we had to pull the engine. And from all I have seen blow boat builders give no thought to needing to work on the engine

Fuzz wrote: ↑Sun May 30, 2021 1:55 pm from all I have seen blow boat builders give no thought to needing to work on the engine

sure they do. You lower the sail and sew on a patch.

Fuzz wrote: ↑Sun May 30, 2021 1:55 pm I am with you, that is to reduce drag. Someone was trying to get the boat to go as fast as possible. If it were a line cutter it would not work there, too far from the prop. Is there screw holes on the back of it to bolt something to it?
Be very happy you do not need to change the cuttless. It would not be too bad with your set up but still a pain. I am in the middle of helping my buddy change his. It is a real pain in the butt To get the shaft out we had to pull the engine. And from all I have seen blow boat builders give no thought to needing to work on the engine

I dont think there are any screwholes, the line cutter theory didnt hold water with me either. As I said, the previous owner was really competitive so no doubt he could have added it to reduce drag.

I pulled the shaft on my 68 century once and it was hellish. Seemed like hours with a slide hammer screwed on the shaft to get it to budge out of the mating plate, whatever that's called. On the sailboat, access to the shaft is excellent if you happen to be sub 3' tall, otherwise it takes a contortionist, which I am not. Luckily this boat gets pretty light use, the engine may get 10-20 hours in a season, so the maintenance is pretty reasonable. All told, this boat probably costs me <$2000/season for storage, mooring, maintenance, it's pretty amazing.

Jaysen wrote: ↑Sun May 30, 2021 5:31 pm

Fuzz wrote: ↑Sun May 30, 2021 1:55 pm from all I have seen blow boat builders give no thought to needing to work on the engine

sure they do. You lower the sail and sew on a patch.

YES! I have a speedy stitcher that works great for a quick patch. My furled genny is pretty old and tired but it keeps working, keeps pulling so not gonna replace it yet!

VT_Jeff that is a shaft smoother or better called an rpm equalizer. Since you have a folding prop it helps maintain an equal rpm on the shaft. Have not seen one in a long time. But my father in law's boat had one up on Lake Erie. At least that is what I recall it being, I may be wrong.

Tom

TomW1 wrote: ↑Sat Jun 05, 2021 12:14 am VT_Jeff that is a shaft smoother or better called an rpm equalizer. Since you have a folding prop it helps maintain an equal rpm on the shaft. Have not seen one in a long time. But my father in law's boat had one up on Lake Erie. At least that is what I recall it being, I may be wrong.

Tom

Interesting theory, Tom. It would not appear to have enough mass to do much in that regard but maybe it doesn't need much, I'll do some research.

Tom is correct but I called that a shaft balancer.

jacquesmm wrote: ↑Mon Jun 07, 2021 9:56 am Tom is correct but I called that a shaft balancer.

Thanks Jaques. Now when I ignore it I'll know what I'm ignoring.

VT_Jeff wrote: ↑Mon Jun 07, 2021 11:57 am

jacquesmm wrote: ↑Mon Jun 07, 2021 9:56 am Tom is correct but I called that a shaft balancer.

Thanks Jaques. Now when I ignore it I'll know what I'm ignoring.

Use caution when ignoring. A balancer is used to offset rotational masses (think wheel weights). If you have an unbalanced rotational mass you are stressing the bearings and support structure (think wheels). If you have a prop or shaft that is unbalanced you could end up with some shakes and shimmies that are unpleasant or that lead to premature wear.

Or it could be fine...

Jaysen wrote: ↑Mon Jun 07, 2021 12:31 pm

VT_Jeff wrote: ↑Mon Jun 07, 2021 11:57 am

jacquesmm wrote: ↑Mon Jun 07, 2021 9:56 am Tom is correct but I called that a shaft balancer.

Thanks Jaques. Now when I ignore it I'll know what I'm ignoring.

Use caution when ignoring. A balancer is used to offset rotational masses (think wheel weights). If you have an unbalanced rotational mass you are stressing the bearings and support structure (think wheels). If you have a prop or shaft that is unbalanced you could end up with some shakes and shimmies that are unpleasant or that lead to premature wear.

Or it could be fine...

yeah, it'll probably be fine. It's always had a vibration at certain RPM's and always been smooth at others, so I just use the smooth ones and stay away from the rough ones. Barring a real issue, it's going to remain ignored.

You could pull the prop and have it balanced. I’ve been told that most of the time it is the prop that needs tweaked.

I am now ignoring this thread...

cape man wrote: ↑Mon Jun 07, 2021 1:22 pm I am now ignoring this thread...

Seems like the right plan.

I would respond but then it would be proof that I am not totally ignoring this thread... which I am... well maybe.

cape man wrote: ↑Mon Jun 07, 2021 2:55 pm I would respond but then it would be proof that I am not totally ignoring this thread... which I am... well maybe.

Reminds of a few years back when my kids kept yelling at each other “I’M NOT TALKING TO YOU” for about 300mi non stop. Mile 301 they walked out of the Waffle House to an empty parking space. I was just as shocked as they were. When she finally came back no one was saying anything to anyone (in actual silence this time).

Oddly we’ve never had that particular problem a second time.

Did you just threaten to delete this thread? I come back here and it's gone?

Jaysen wrote: ↑Mon Jun 07, 2021 1:16 pm You could pull the prop and have it balanced. I’ve been told that most of the time it is the prop that needs tweaked.

This is a solution looking for a problem. I currently have plenty of problems without solutions, so there's no need to start working in reverse. If that changes, your advice will take priority.