Another Hunter Rudder!

[MARC D]

I wonder what would be the increase in selling price if boat manufacturers were fitting solid rudder shaft instead of hollow?
Or as an option? I guess it would be a popular one. Is anyone have ever heard of a breakage of a solid rudder shaft in deep water??

[fgd3]

Originally Posted by robert sailor

Hi Fabbian,
I think the transom rudder is a very good design that is very easy to work on especially on cruising boats but it stalls easier than a spade because it doesn't have the end plate effect that a spade rudder has.

Thanks for that explanation. I don't know about the end plate effect. I guess the hull right above the rudder prevents vortices from spinning off the top of the rudder as they do off the bottom. But doesn't the sea surface through which the outboard rudder passes prevent those vortices from forming?

Originally Posted by robert sailor

Its also not a balanced design or at least not as well balanced as a spade

It's true that outboard rudders are often not balanced, but there is no reason they can't be. It's quite easy to extend the leading edge of the rudder forward of its axis of rotation.

Originally Posted by robert sailor

and there for the forces can be much higher.

A balanced rudder requires less torque to turn, so steering requires less effort. No other forces are changed. I wasn't sure if that's what you meant.

Fabbian

[fgd3]

Originally Posted by hellosailor

Fabian, the foam filling would add so little to the rudder strength that it might simply have been done to ensure water could not condense in there and rot the tube out from the inside. Or, to ensure more buoyancy allowing the rudder to be dropped and refitted in the water. Unless the foam was as dense as concrete, odds are it was there as a filler, not a structural component.

The trouble with that line of thinking is water exclusion and buoyancy could have been achieved just as well with a much less dense (and less expensive) foam. The high density foam used only makes sense for strengthening the rudder shaft.

Fabbian

[fgd3]

Originally Posted by robert sailor

Hi Fabbian,
I think the transom rudder is a very good design that is very easy to work on especially on cruising boats but it stalls easier than a spade because it doesn't have the end plate effect that a spade rudder has. Its also not a balanced design or at least not as well balanced as a spade and there for the forces can be much higher.

After I replied to your post I saw you had already answered some of my questions in subsequent responses to the same questions raised by others.

Fabbian

[fgd3]

Originally Posted by RTB

After running through this thread a bit today, I sent an email to Al at Foss Foam. I asked about the reason for having foam in the rudder post. As I have mentioned, I'm a happy customer, but curious. I got this reply back from him this evening -

Thanks for your e-mail. I'm glad to hear that your rudder is performing well. The reason we foam fill the shafts it to prevent moisture from going down inside the tube. Before we started foaming the shafts there was an issue with water going down the shaft and freezing and busting out the side of the rudder during freezing weather. Since we don't know where a boat may wind up we foam fill all shafts. That is a great question!
Thank you,



Bob "Al" Walker
Foss Foam Products of Florida, Inc.

www.newrudders.com
PH 352-529-1104
Fax 352-529-1106


I think a same-day reply to a customer's question is pretty awesome, and says a lot for the company.

Ralph
Sea turtle visitor | sailing away with R & B

It's hard to argue with that. I guess it settles the question.

If you had seen the rudder shaft on my Hunter 25 I think you'd find it hard to believe such a thin wall would be up to the loads a rudder places on the shaft without some internal reinforcement.

I'm going to quit arguing the foam was there to strengthen the shaft.

Thanks, Ralph, for doing that research.

Fabbian

[Paul Elliott]

Originally Posted by fgd3

Thanks for that explanation. I don't know about the end plate effect. I guess the hull right above the rudder prevents vortices from spinning off the top of the rudder as they do off the bottom. But doesn't the sea surface through which the outboard rudder passes prevent those vortices from forming? [...]

Actually, it's probably worse than that. At the air/water interface vortices can form that create whirlpools, sucking air down the surface of the rudder which causes even worse flow separation and loss of rudder effect.

[Kenomac]

Having owned a 1998 Hunter 450 and sailed it quite a bit over a two year period, I'm going to make a first hand observation related to an above post and let others draw their own conclusions. Our Hunter and an identical 450 owned by a friend always required lots of effor to steer, even in say 10-15 knot winds, it always seemed quite impossible to get the steering in a balanced situation with the sails. When I say lots of effort, I mean it always felt like we were fighting with the wheel and it wore us out, even our first mate Ray the auto pilot would discharge the batteries more than expected.

On our new Oyster 53 with a balanced skeg hung rudder, this is not the case. The boat practically sails itself with very little effort at the helm. The sails can easily be trimmed to have the tiller balanced in the center, and our new mate Ray, can sail all day only discharging the batteries about 1-2 amp hours per hour. Even in 25-35 knot winds, there's very little effort required to steer the boat.

I think this might be relative to why other people have experienced rudder failure on Hunters. Our Hunter rudder never failed, but it surely was exposed to loads that our much larger Oyster never sees.

Just an observation.

[sailorboy1]

My rudder works GREAT! It turns easy, steers the boat without any issue, I set my autopilot at response 2 (with 10 being the highest), normally is at about 2 degrees when I set the sails.

If your boat is not able to do the same it probably is you, not your rudder.

[transmitterdan]

Originally Posted by Kenomac

Our Hunter and an identical 450 owned by a friend always required lots of effor to steer, even in say 10-15 knot winds, it always seemed quite impossible to get the steering in a balanced situation with the sails.

A friend of mine has a Hunter ( sorry I don't know the model but it is about 37 ft.) and we sailed with them a good deal before we bought our own boat. The layout is very nice and we like that boat a lot. It is possible to balance the sails on their Hunter. But if wind speed increases even 3-5 knots the balance is thrown off and it quickly becomes harder to steer. In larger puffs the wheel actually tried to lift me off the cockpit floor and I'm not a light person. I thought this behavior was how all larger boats worked until I first sailed our current boat (Valiant 42). The Valiant rudder is skeg hung but the rudder post is close to the leading edge of the foil so not truly balanced like a spade can be. But I can steer the Valiant with 2 fingers on the wheel nearly all the time. If I can't it is long past time to reduce sail.

I am not a naval architect but I read Bob Perry's book. He says that helm balance has as much to do with mast placement as sail plan. The latter the sailor can control but not the former. Perhaps this is what is going on with my friend's boat. Maybe mast placement coupled with sail selection causes the sudden increase in weather helm. I have sailed on other boats with varying degrees of the same thing (C&C) but that Hunter always sticks in my mind as having a lot of weather helm and rudder feedback. It's like balancing a needle on the pointy end.

One other point about forces on balanced spade rudders is that the helm pressure is not always indicative of pressure on the rudder post. The whole point of a well balanced rudder is to reduce helm pressure. So the pressure on the post can be very high but not perceived as such by the helms person unless they are keeping a close eye on rudder angle.

[boatman61]

Dunno who made the rudder on my Cherubini H37c but all I can say is she sailed just fine... 2,500 miles of steering by hand crossing the pond was a killer but it was not due to weather helm... more to do with 16hr spells at the wheel... the other 8hrs hove to and asleep.
Crap new Simrad AP... belts were useless..

[neilpride]

Could be because Hunter use the B&G rig , big mainsail with lot or roach , unbalanced sailplan? small rudder? weather helm.

[Rakuflames]

N

Originally Posted by neilpride

If Hunters are fited with foss foam rudders that mean hunters are painted white at the antifouling?? from the factory? are new owners aware of this isue with dark colors?

No. Unpainted covered witb mold release wax.

[forsailbyowner]

Originally Posted by Don L

Maybe the rudders are too strong, which means the shafts take a higher stress. All depends how you what to spin it isn't it?

Aren't we talking about an mid 80s boat here? Who knows want has happened to that boat over the years.

1 yard with 3 Hunters with rudders broken sounds like a story. I have never seen or personally met anyone with a broken rudder. I have never seen anyone at the 2 marinas I use in/off season remove of replace their rudder.

Rudders like keels don't just break and fall off, they get help. The help may have been a year prior.

My brother was in plenty of water when his rudder FELL OFF! It was a POORLY
Designed rudder with a fiberglass shaft that had been REDESIGNED AT HUNTERS REQUEST and replaced with a stainless shaft. If it were on a car it would have been recalled. A recall on these rudders would be the fair and honest thing for hunter to do, instead the poor owners get to foot the $5k plus bill for the rudder and the unnecessary towing and rescue costs involved. I lost two rudders on my first boat before replacing the rudder with a home design swing up rudder( boat had centerboard that would swing up at grounding and expose rudder to harm) When I saw the Morgan 33 OI on stands I said to myself "thats how a rudder should be attached" and is one of the main reasons I bought her.

http://sailboatdata.com/imagehelper.asp?file_id=6788

[Rakuflames]

Originally Posted by neilpride

Could be because Hunter use the B&G rig , big mainsail with lot or roach , unbalanced sailplan? small rudder? weather helm.

Most hunters sail well to weatber. Mine does so well. I can't imagine that one boat having a poorly placed mast. And mine easily steers. Lots of extra oomph left for a storm. I suspect a change in sails is needed. Mine will handle badly if tbe headsail is too bjg for conditions.

[Rakuflames]

Originally Posted by Don L

My rudder works GREAT! It turns easy, steers the boat without any issue, I set my autopilot at response 2 (with 10 being the highest), normally is at about 2 degrees when I set the sails.

If your boat is not able to do the same it probably is you, not your rudder.

Migh have had wrong combo of sails. Toomuch headsail makes my boat a bit kf a wrestling match. Balanced well, my 31 from 1983 sails fast true steady and easy to keep on course.