Lubricant for rudder bearings

[TJ D]

Hello forum,

We are getting ready for a long passage, and I would like to get some lubrication into our lower rudder bearings.

The bearings are similar to the 'Jefa' units in construction, but different materials.

The 'outer race' of the bearing is carbon fiber, and the 'inner race' is an oblate sphere made out of stainless. The bearings are not in the water when the boat is flat, but are submerged when heeled. (we have twin rudders)

I've noticed that when reaching in strong conditions, the wheel gets stiff when the rudder has a lot of side load. I would like to find some kind of a spray that I can pop the seal off at the top of the rudder tube, spray said (eco friendly) lube in, and reinstall the top seal. removing the rudders is not an option before leaving.

Any ideas? Something with Teflon? It needs to be at least somewhat waterproof, and since they're under water some of the time, We don't want any petroleum in there.

Thanks for the ideas. TJ

[UNCIVILIZED]

I'd imagine that the builder knows what make the bearings are, & could put you in touch with the company. Especially as, if it's the boat which I think it is, it's one which they get a lot of inquiries about. So the records on her should be pretty easy to access.
Ditto on contacting the designer for the specs on them.

[TJ D]

Uncivilized,

Thanks. The designer doesn't remember who made the bearings. It's been a long-standing situation on the boat, since new, actually. It's not terrible, but when we're sailing fast at tighter wind angles, the friction can make the loads on the pilot drive a bit much. I can't contact the builder, don't know where he is. This seems to happen only when we're reaching at speeds of more than 10 knots or so. Our solution at the moment is to either reef and let the pilot do the job, or hand steer if we want to go faster. Not ideal, but we can slow her down to 8 or 9 and go into normal cruising mode. It would be nice to be able to use the pilot and still be able to sail faster.

Downwind, there is no problem. We've been surfing at speeds pushing 20, and auto manages just fine. It's just a side-load friction problem.

Anyway, it's stainless rubbing on carbon submerged in seawater. This should be enough info for somebody to make a recommendation, I hope. There may not be an answer to this.

The next time we're hauled out, I'm going to try to get roller bearings made to the same specs, but this does not help us for our passage coming in a couple of weeks. We're expecting a dose of strong winds on this one, so I was hoping to find a stopgap measure to lube things up in the meantime.

Thanks for the feedback.

TJ

[mrm]

Probably a somewhat crazy idea, but.. how about lanolin?

Technical Lanolin

[TJ D]

You, sir, have won the great idea of the day award. At least in my book.

Lanolin it is! I think that it will probably stick to the bearing surfaces for long enough to be useful, it's environmentally good to use.

Thank you. Now I need to find out where to buy some lanolin with the right viscosity. I need to be able to pour it because I can't reach the bearing, but I don't want it to be too thin, either.

Time to have a look at Amazon, I guess.

TJ

[Schooner Chandlery]

Suggest you work with a naval architect or engineer to design a better bearing for this application. I am a mechanical engineer and I would never consider roller bearings as you suggest you will do. There are many engineered materials that your selected expert may spec for you. It is possible you are experiencing simple wear or movement due to something not in proper alignment.

Lanolin works short term for many things but would be an unlikely long term solution for your situation as described.

Best of luck,
Brenda


Sent from my iPhone using Cruisers Sailing Forum

[TJ D]

Hi Brenda, we are in semi-frequent touch with the designer of our boat. Of course he'll be consulted.

I think that we might be using different definitions of roller bearings, however. I am referring to the UHMW/Ertelite(sp) bearings that are found most commonly on bigger racing boats. No metal parts, of course.

I'm quite sure that we don't have an alignment issue. It's a friction situation that is generated only during times of high side loading on the rudder. As I mentioned, we have 2 rudders, so the leeward rudder is digging quite hard. They are also asymmetrical to provide lift, so this contributes to the side loading as well. I really think that it's a matter of simple friction.

We've sailed the boat about 10,000 ocean miles to this point, so this is not a major problem, but there are times when it's noticeable. When we do our next refit, we'll look at a better solution, but in the meantime, some good slick stuff to ease the friction can do nothing but help. Certainly I did not think that lanolin was a permanent solution...

Thanks, TJ

[Paul L]

This sounds more like the shafts are bending under load rather than friction.

You can heat the lanolin to soften it for application. I doubt it will last very long.

[TJ D]

Hi Paul,

That's not correct, there is no bending of the rudder shaft. The wall thickness is nearly an inch on the shafts constructed of carbon fiber, and the load is carried top and bottom. If there were bending happening, it would be apparent at the lip seal at the top of the stern tubes. It's just not happening.

I've been down there watching the shafts with the boat doing 12-14 knots, and it's rock solid, no deflection. The lip seals are basically right at the middle of the point between bearings, so it would be obvious.

As I mentioned, the rudders are designed to provide lift to a degree not found in conventional rudders, so high speed reaching generates a lot of side force. I'm 100% sure it's friction in the lower bearing.

Thanks for the suggestion, though.

TJ

[Schooner Chandlery]

Originally Posted by TJ D

Hi Brenda, we are in semi-frequent touch with the designer of our boat. Of course he'll be consulted.

I think that we might be using different definitions of roller bearings, however. I am referring to the UHMW/Ertelite(sp) bearings that are found most commonly on bigger racing boats. No metal parts, of course.

I'm quite sure that we don't have an alignment issue. It's a friction situation that is generated only during times of high side loading on the rudder. As I mentioned, we have 2 rudders, so the leeward rudder is digging quite hard. They are also asymmetrical to provide lift, so this contributes to the side loading as well. I really think that it's a matter of simple friction.

We've sailed the boat about 10,000 ocean miles to this point, so this is not a major problem, but there are times when it's noticeable. When we do our next refit, we'll look at a better solution, but in the meantime, some good slick stuff to ease the friction can do nothing but help. Certainly I did not think that lanolin was a permanent solution...

Thanks, TJ

Element 1.2 of wiki here is what I refer to as roller bearings https://en.wikipedia.org/wiki/Rolling-element_bearing

A sleeve is not what I thought you meant.

If you are overloading the water lubricated steel and cf bearing surface it will have a great deal of friction--and wear--so I wish you luck in getting it all sorted out. There is really no film thickness to speak of when something is water lubricated so everything should be smooth operating and not worn or it will have more and more problems.

If you are in touch with your designer, you can get the specs from him/her for the design, load calcs, and expected service life. You may be able to get drawings of it as well depending on the timeframe the boat was designed. Recently, it should be on cad and available. I have never designed a system or repair for a client that I didn't document the method, materials, and at least have a sketch in my notebook of it, so your designer probably has similar.

There can very well be bending and/or flex that you wouldn't expect nor be able to see visually even while loaded. It takes very, very little movement out of the proper alignment for something like a rudder to cause a good deal of friction when highly loaded.

10K miles is nothing. You should ask your designer what the design life was for your rudder bearing surfaces.

Have a great time with your boat.

[model 10]

If you can afford 2 rudders you could get some nice aerospace grease. I don't have the mil-spec # on hand but it's available in 3.5oz tubes for about $250

[petter5]

Originally Posted by TJ D

Hello forum,

We are getting ready for a long passage, and I would like to get some lubrication into our lower rudder bearings.

The bearings are similar to the 'Jefa' units in construction, but different materials.

The 'outer race' of the bearing is carbon fiber, and the 'inner race' is an oblate sphere made out of stainless. The bearings are not in the water when the boat is flat, but are submerged when heeled. (we have twin rudders)

I've noticed that when reaching in strong conditions, the wheel gets stiff when the rudder has a lot of side load. I would like to find some kind of a spray that I can pop the seal off at the top of the rudder tube, spray said (eco friendly) lube in, and reinstall the top seal. removing the rudders is not an option before leaving.

Any ideas? Something with Teflon? It needs to be at least somewhat waterproof, and since they're under water some of the time, We don't want any petroleum in there.

Thanks for the ideas. TJ

Mercruiser "Spline Grease" is excellent for this type of use. Will stay on the rudder shaft "for ever" and gives good lubrication in salt water exposed areas. Also east to purchase manty places. Mercruiser High Performance Extreme Grease Lube Spline Coupler 92 8M0071841 | eBay

[TJ D]

Originally Posted by Schooner Chandlery

Element 1.2 of wiki here is what I refer to as roller bearings https://en.wikipedia.org/wiki/Rolling-element_bearing

A sleeve is not what I thought you meant.

If you are overloading the water lubricated steel and cf bearing surface it will have a great deal of friction--and wear--so I wish you luck in getting it all sorted out. There is really no film thickness to speak of when something is water lubricated so everything should be smooth operating and not worn or it will have more and more problems.

If you are in touch with your designer, you can get the specs from him/her for the design, load calcs, and expected service life. You may be able to get drawings of it as well depending on the timeframe the boat was designed. Recently, it should be on cad and available. I have never designed a system or repair for a client that I didn't document the method, materials, and at least have a sketch in my notebook of it, so your designer probably has similar.

There can very well be bending and/or flex that you wouldn't expect nor be able to see visually even while loaded. It takes very, very little movement out of the proper alignment for something like a rudder to cause a good deal of friction when highly loaded.

10K miles is nothing. You should ask your designer what the design life was for your rudder bearing surfaces.

Have a great time with your boat.

Hi Brenda,

The bearings have been replaced in the time I have owned the boat. The life of them is known, and it is considered a maintenance item with this type. The boat came with several spares, and a set has recently gone in. That's not the issue.

Binding due to flex/misalignment is also not an issue. I am confident of that. The bearings will tolerate a deflection of more than 10 degrees or so and will still work. It's a 'ball and socket' setup, and will allow for this.

Anyway, CF is not really known for it's flexibility. The rudder posts would have long since broken in half for them to create enough misalignment to be an issue.

I think that it's really just an issue of design. It's been a (minor) issue since the boat was new, and is still a minor issue. She has sailed more than just the 10k I've put on her. I believe she's done 2 transpacs, another recreational Hawaii trip, 2 transatlantics, and much more in between. All with the same rudder bearing setup. I just want to make it better. In the meantime, as we get ready to do another transatlantic, I want to find a suitable lubricant to make it a bit smoother until we do our next refit.

Now, if we can get back to the immediate topic at hand, thanks to the previous two of you for the suggestions. Really, the problem with grease is that I don't have access to the bearing insides without taking the rudders out of the boat, which I'm not going to do. I really need to find a spray or a liquid.

I'm not quite sure how 2 rudders makes one's grease budget bigger, however...


Thanks to all. TJ

[deblen]

Originally Posted by TJ D

Hello forum,

We are getting ready for a long passage, and I would like to get some lubrication into our lower rudder bearings.

The bearings are similar to the 'Jefa' units in construction, but different materials.

The 'outer race' of the bearing is carbon fiber, and the 'inner race' is an oblate sphere made out of stainless. The bearings are not in the water when the boat is flat, but are submerged when heeled. (we have twin rudders)

I've noticed that when reaching in strong conditions, the wheel gets stiff when the rudder has a lot of side load. I would like to find some kind of a spray that I can pop the seal off at the top of the rudder tube, spray said (eco friendly) lube in, and reinstall the top seal. removing the rudders is not an option before leaving.

Any ideas? Something with Teflon? It needs to be at least somewhat waterproof, and since they're under water some of the time, We don't want any petroleum in there.

Thanks for the ideas. TJ

Fluid Film is lanolin in a spray can. Sticks well in water.
https://www.amazon.com/Fluid-Corrosi.../dp/B008N3J4PS

[Jim Cate]

TJ, I can't quite visualize your setup, so this may be of little use... but, macLube seems like it might fill the bill. Spray application, good high pressure film strength, easy to source.

And re lanolin: I believe that that wonderful stuff is not a good high pressure lubricant, and might not do much good in your application even if you could work out a means of applying it. I'm curious as to the source of your antipathy towards petroleum based lubricants. The environmental insult resulting from a few grams of such applied to your rudder bearings, and then perhaps released into the sea over months of sailing... well, that is beyond immeasurably small. The trace amounts of oil and unburned diesel that are in your engine exhaust are orders of magnitude greater. I'm all for environmental sensitivity in our actions, but some idea of scale is required in our decisions. But, perhaps I have misunderstood your post on that aspect.

Good luck in finding a useful solution, and have a good passage.

Jim