Help.... Donnybrook is a 1975 CD28 and I have a question concerning the rudder post. I'm starting to notice a little excessive play in the fore and aft movement of the tiller. Also, today in somewhat heavy seas, the rudder seemed to slap around on it's own without any movement of the tiller. Is the rudder post a solid post from the rudder to the tiller attach point? Where is the bearing for the rudder post located and how difficult is it to replace? Thanx for any input.
Ben
Rudder post on CD 28
Moderator: Jim Walsh
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Ben schifano
- Posts: 34
- Joined: Apr 25th, '05, 20:05
- Location: 1975 Cape Dory 28, Hull#46 "Donnybrook" Rochester New York
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paul marko
- Posts: 76
- Joined: Mar 5th, '05, 21:45
- Location: CD28/77,Ixcatl/port charlotte Fl.
Play in rudder post
My 77/cd 28 has a solid bronze shaft which "seems" to go from the rudder post in the cockpit to a grougion on the heal plate which is located on the aft end of the keel. There is about 1/8" amount play between the shaft and the fiber glass tube that goes from the top of the rudder into the cockpit about the same amount of play at the heal plate.
The rudder has little to no vibration but cavitation water,when under power, does migrate up the fiber glass tube into the cockpit.
The simplest way to eliminate the water migration would be to put a grease zirk near the top of the FG tube and keep it greased. On my boat there is no bearing.
I guess if you are experiencing a lot of vibration you might want to examine the rudder shaft attachment at the heel plate, if not much play here, then examine attachment of rudder to the bronze shaft.
good luck and let me know what you find out.
Paul Marko
The rudder has little to no vibration but cavitation water,when under power, does migrate up the fiber glass tube into the cockpit.
The simplest way to eliminate the water migration would be to put a grease zirk near the top of the FG tube and keep it greased. On my boat there is no bearing.
I guess if you are experiencing a lot of vibration you might want to examine the rudder shaft attachment at the heel plate, if not much play here, then examine attachment of rudder to the bronze shaft.
good luck and let me know what you find out.
Paul Marko
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Ben schifano
- Posts: 34
- Joined: Apr 25th, '05, 20:05
- Location: 1975 Cape Dory 28, Hull#46 "Donnybrook" Rochester New York
RUDDER POST ON cd28
Thanx for the input....the water migration I can live with. My big concern is the possibility of a loss of rudder control while under way. With 6-8 weeks left in the sailing season, that is my main concern.
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S/V Necessity
- Posts: 147
- Joined: Jun 13th, '06, 23:38
- Location: 1981 CD28 #305
Columbia, MO
Rudder Construction
I've got the rudder off my cd28 right now. The shaft is stainless, and I have some serious corrosion on it... So I will probably be building another. However after pricing bronze vs stainless I'll probably go stainless again 
In the process I will be grinding and cutting into the old one to determine it's condition and construction. I'll try and post some pictures. Might be a couple of weeks though.
Mine had a bearing surface at the cockpit floor, and the heel fitting. That's it, it didn't touch anywhere else. And I dont know if it's proper to say bearing surface at the heel fitting, it's just a stainless steel pin driven into the heel fitting. The rudder rotates on this pin. I guess that it's possible that your shaft has failed internally (within the fiberglass rudder) But I'd be pulling the fitting off that sits at your cockpit floor first. It's the easiest and most likely culprit.
In the process I will be grinding and cutting into the old one to determine it's condition and construction. I'll try and post some pictures. Might be a couple of weeks though.
Mine had a bearing surface at the cockpit floor, and the heel fitting. That's it, it didn't touch anywhere else. And I dont know if it's proper to say bearing surface at the heel fitting, it's just a stainless steel pin driven into the heel fitting. The rudder rotates on this pin. I guess that it's possible that your shaft has failed internally (within the fiberglass rudder) But I'd be pulling the fitting off that sits at your cockpit floor first. It's the easiest and most likely culprit.
rudder problems
You can check out the rudder set up at http://www.capedory.org/manuals/Ty-Ty%2 ... 30-30K.pdf.
One thing to check would be the tiller strap and cap, the bronze gizmo that attaches the wooden tiller to the top of the rudder post. If that's o.k., then check the bearing sleeve/cylinder where the rudder post comes out of the rudder post tube just above the cockpit sole. Wear here could account for some play in the tiller. If the degree of wear isn't too bad, you might want to live with it since removal and replacement would probably require hauling the boat and dropping the rudder until the post drops below the bearing sleeve.
If the rudder is moving back and forth and the rudder post isn't rotating---and causing the tiller to move back and forth in unison with the rudder---then a more serious problem is likely. This would be a weakening of the bond between the rudder post and the polyester adhesive/filler that was used to fill the two halves of the fiberglass rudder shell and to bond the rudder post to the rudder. The most likely culprit would be water getting inside the rudder shell and degrading the integrity of the rudder post-polyester bond. I think there have been some posts on this topic.
If it looks like it's a problem with the bond between the post and the rudder, I would be hesitant to go sailing until the issue has been resolved.
One thing to check would be the tiller strap and cap, the bronze gizmo that attaches the wooden tiller to the top of the rudder post. If that's o.k., then check the bearing sleeve/cylinder where the rudder post comes out of the rudder post tube just above the cockpit sole. Wear here could account for some play in the tiller. If the degree of wear isn't too bad, you might want to live with it since removal and replacement would probably require hauling the boat and dropping the rudder until the post drops below the bearing sleeve.
If the rudder is moving back and forth and the rudder post isn't rotating---and causing the tiller to move back and forth in unison with the rudder---then a more serious problem is likely. This would be a weakening of the bond between the rudder post and the polyester adhesive/filler that was used to fill the two halves of the fiberglass rudder shell and to bond the rudder post to the rudder. The most likely culprit would be water getting inside the rudder shell and degrading the integrity of the rudder post-polyester bond. I think there have been some posts on this topic.
If it looks like it's a problem with the bond between the post and the rudder, I would be hesitant to go sailing until the issue has been resolved.
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Ben schifano
- Posts: 34
- Joined: Apr 25th, '05, 20:05
- Location: 1975 Cape Dory 28, Hull#46 "Donnybrook" Rochester New York
Cd28 rudder post
Thanxs everyone for the valuable input. I don't know what I would do without all the knowledgeable sailors on this site. My wife and I will moor the boat near the beach tomorrow, and I will check out the integrity of the bond on the rudder. Thanks again.
Ben
Ben
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Oswego John
- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
CD 28 Rudder Post
Hi Ben,
I could be wrong, but I don't think that you will be able to check the integrity or strength of the bond between your rudder post and the rudder blade.
The fiberglass and epoxy found at the leading edge of the rudder blade helps seal the joint between the two halves of the blade. It also helps to make the joint between the two blade halves and the rudder post waterproof.
Some people shun the use of stainless under water. They prefer the use of the more expensive bronze. Metalurgists have, in the past, pointed out to us that stainless steel, when deprived of oxygen, deteriorates whereby bronze isn't affected as much. This is not to say that you shouldn't continue the use of stainless. I think more of the larger boats use SS than bronze
To my knowledge, there is no epoxy and glass bond known to man that will adhere the rudder blade to the rudder post and, at the same time, be able to transfer the torque of the post to the blade.
In order to transfer this tremendous torque into the blade, most of the CDs that I'm aware of have fingers of the same metal welded to the aft end of the post. These fingers extend well into the core of the rudder blade. The two halves of the rudder blade envelope the fingers as a sandwich and all the components are sealed with fiberglass and epoxy. When I repaired or rebuilt rudders, I substituted the use of one large, trapezoidal shaped blade rather than the use of many smaller fingers. This enhanced the ability to transfer torque and provided many more running inches of weldment.
These welded fingers have been known in the past to break away from the post. Sometimes they deteriorate from electrolysis in time after the waterproofing has been compromised.
If you, or someone that you know dives, I suggest that you have your wife gently turn the tiller/wheel as the diver holds the blade firmly. If the blade rotates as one with the post, chances are that there is not much trouble within the blade halves or the post/blade joint. After this check, visually look for any crack or delamination or failure of the fiberglass, especially at the foreward edge of the post/blade joint. Physically test to see if there is any movement in any direction between the post and the blade.
If the post turns and the blade remains stationary, it's a sign of deep trouble. Don't use the boat until the trouble has been corrected. It is possible that the entire rudder can become detached from it's post and fall off, never to be recovered.
Good luck,
O J
I could be wrong, but I don't think that you will be able to check the integrity or strength of the bond between your rudder post and the rudder blade.
The fiberglass and epoxy found at the leading edge of the rudder blade helps seal the joint between the two halves of the blade. It also helps to make the joint between the two blade halves and the rudder post waterproof.
Some people shun the use of stainless under water. They prefer the use of the more expensive bronze. Metalurgists have, in the past, pointed out to us that stainless steel, when deprived of oxygen, deteriorates whereby bronze isn't affected as much. This is not to say that you shouldn't continue the use of stainless. I think more of the larger boats use SS than bronze
To my knowledge, there is no epoxy and glass bond known to man that will adhere the rudder blade to the rudder post and, at the same time, be able to transfer the torque of the post to the blade.
In order to transfer this tremendous torque into the blade, most of the CDs that I'm aware of have fingers of the same metal welded to the aft end of the post. These fingers extend well into the core of the rudder blade. The two halves of the rudder blade envelope the fingers as a sandwich and all the components are sealed with fiberglass and epoxy. When I repaired or rebuilt rudders, I substituted the use of one large, trapezoidal shaped blade rather than the use of many smaller fingers. This enhanced the ability to transfer torque and provided many more running inches of weldment.
These welded fingers have been known in the past to break away from the post. Sometimes they deteriorate from electrolysis in time after the waterproofing has been compromised.
If you, or someone that you know dives, I suggest that you have your wife gently turn the tiller/wheel as the diver holds the blade firmly. If the blade rotates as one with the post, chances are that there is not much trouble within the blade halves or the post/blade joint. After this check, visually look for any crack or delamination or failure of the fiberglass, especially at the foreward edge of the post/blade joint. Physically test to see if there is any movement in any direction between the post and the blade.
If the post turns and the blade remains stationary, it's a sign of deep trouble. Don't use the boat until the trouble has been corrected. It is possible that the entire rudder can become detached from it's post and fall off, never to be recovered.
Good luck,
O J
rudder construction follow-up
The owner's manual diagram for the rudder construction of the Typhoon rudder shows weldments on the aft of the rudder post extending back into the rudder blade, as Oswego John describes above. But the diagram for the CD27/28 rudder construction shows no such weldments. Instead, the rudder post itself is shown as having two bends, that would, it seems, provide some fore-and-aft strengthening of the rudder post to rudder blade bond similar to aft facing weldments.
http://www.capedory.org/manuals/Ty-Ty%2 ... 30-30K.pdf page 53
Is this diagram correct for the CD27/28 rudder construction, or were additional welded components left out of the diagram?
http://www.capedory.org/manuals/Ty-Ty%2 ... 30-30K.pdf page 53
Is this diagram correct for the CD27/28 rudder construction, or were additional welded components left out of the diagram?
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Oswego John
- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
There, I Did It Again
Hi SPIBob,
I'm not sure but I think that I owe you an apology of sorts.
It seems that lately, the only exercise that I'm getting is jumping to conclusions.
The art of building Cape Dories has come a long way since the time when they first went into business. The early model rudders were built of three wooden boards, tied together with long bronze bolts and nuts. This method had it's own intrinsic problems.
CD got away from the wooden, solid rudder and went to the fiberglass, two piece rudder along with the welded fingers.
I'm going to divulge a secret that I've been living with lo these many years. After CD went with the bent rudder post on the larger models, I have never had the occasion to repair any of that style. I've never seen what the inside of the larger rudders look like. It's like they never quit, a good, solid unit.
The vast majority of the rudder repairs, both wooden and fiberglass, were on the smaller CD models up to 25 feet.
So looking at the plan of the bent post rudders, I can see how the torque of the tiller is transferred to the rudder blade and I have to agree that it seems to be doing the job quite well.
BTW, The CD 25s did away with the welded fingers and, from what I notice, went to the welded fin inside of the fiberglass, two piece rudder blade.
Sorry,
O J
I'm not sure but I think that I owe you an apology of sorts.
It seems that lately, the only exercise that I'm getting is jumping to conclusions.
The art of building Cape Dories has come a long way since the time when they first went into business. The early model rudders were built of three wooden boards, tied together with long bronze bolts and nuts. This method had it's own intrinsic problems.
CD got away from the wooden, solid rudder and went to the fiberglass, two piece rudder along with the welded fingers.
I'm going to divulge a secret that I've been living with lo these many years. After CD went with the bent rudder post on the larger models, I have never had the occasion to repair any of that style. I've never seen what the inside of the larger rudders look like. It's like they never quit, a good, solid unit.
The vast majority of the rudder repairs, both wooden and fiberglass, were on the smaller CD models up to 25 feet.
So looking at the plan of the bent post rudders, I can see how the torque of the tiller is transferred to the rudder blade and I have to agree that it seems to be doing the job quite well.
BTW, The CD 25s did away with the welded fingers and, from what I notice, went to the welded fin inside of the fiberglass, two piece rudder blade.
Sorry,
O J
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Ben schifano
- Posts: 34
- Joined: Apr 25th, '05, 20:05
- Location: 1975 Cape Dory 28, Hull#46 "Donnybrook" Rochester New York
CD28 Rudder post
A little update.... After mooring Donnybrook and donning mask and snorkel,it appears that the rudder play originates at the base of the tiller. The rudder itself seems to be firmly attached to the rudder post. I assume that I can sail until pullout in 2 months. Thanks everyone for all your valuable input.
Ben
Ben