How can you tell the rudder delamination is serious

Ross · May 31, 2009

Are you able to examine the delamination? Can you insert a knife blade into the gap? How long is the gap? Have you tapped the surface of the rudder? Does it sound solid or hollow? How far can you sail without a rudder?

sailingdog · May 31, 2009

A lot depends on the interior structure of the rudder. Is the rudder's web and stock okay? If the rudder stock and webbing are stainless steel, which is often the case, a delaminated rudder may have serious corrosion issues with the stock and webbing—and in some cases the webbing corroding is the cause of the delamination, as stainless steel expands about 10% when it corrodes.

Ian4781 · May 31, 2009

In an area like Chazy NY...If I remember correctly is on lake Champlain ,you should not have a corrosion issue assuming that your boat is not from salt water,more likely a crack with water infiltration and a freeze thaw.I would clean the area out well and inject some epoxy....If you were off on a blue water cruise I would replace the unit,but more out of peace of mind than of need

Ross · May 31, 2009

I am always amazed by the knowledge exhibited by folk that have not had a chance for hands on inspection. I could tell you that the fender on my car is bent and I wonder if it is safe to drive and I would get all manner of answers. The omited fact that it was bent in a collision with a CSX frieght train isn't considered as a posibility.
In This case the OP has alluded to a problem of undefined delamination of his rudder. We don't know the extent of this delamination or how the determination was made by the yard that repairs were essential.
We just can't speculate on the need for repairs when we have so little information.

sailingdog · May 31, 2009

Ross-

That's why I'm asking questions...

luvitt · May 31, 2009

i hate to hijack a post, but while everyone is looking here, let me add some of my problem too. maybe it will help the OP.

I tapped all around my hull with a phenolic hammer today. I was listening for the odd sound. the hull sounded great. But when i got to the rudder, I noticed that it sounded hollow--exactly in the midle of vertical & horizontal center. It sounded solid everywhere else. but when i got to that center plane it sounded hollow. about a foot round area.

I have a 40' hunter legend. is it supposed to be hollow? the structure felt solid & intact. i didnt feel any bubbling or bulging fiberglass. it looked & felt normal to the touch. i didnt see any real damage or open hulls in the rudder. i patch a very small nick at the top where it is closest to the hull, but even the underside & leading edge looked fine. its just this small patch in the exact center that sounds hollow. no delam anywhere.

any ideas?

thanks.

Ross · May 31, 2009

Brobins, drill a 1/4 inch hole in the suspect area and see what you hit or don't hit. It is easy enough to repair and can tell you volumes.

Edit to add: Hollow sounding on both sides?

Larry14133 · Jun 1, 2009

Had the same problem

I had the same problem on the same model boat which is on the same lake. a couple of years ago i took the rudder out in the fall, drilled it and let it dry in the basement all winter. It the spring I filled the voids with west system and reinstalled. The problem has not come back.

Regards,

Larry

luvitt · Jun 1, 2009

Ross said:
Brobins, drill a 1/4 inch hole in the suspect area and see what you hit or don't hit. It is easy enough to repair and can tell you volumes.

Edit to add: Hollow sounding on both sides?

Yup, sounds hollow in the same spot on both sides. its just an area about the size of a normal frisbee. the rudder itself seems intact, and solid to the touch, no delam or bulging, not wavy, etc. maybe its supposed to be hollow there?

thanks

Ross · Jun 1, 2009

brobins75 said:
Yup, sounds hollow in the same spot on both sides. its just an area about the size of a normal frisbee. the rudder itself seems intact, and solid to the touch, no delam or bulging, not wavy, etc. maybe its supposed to be hollow there?

thanks

If you drill it and it is delaminated and not hollow, Then you can drill several holes and with a caulking tube filled with slightly thickened resin start pumping from the botton hole and as you fill the void the resin will start bleeding from the other holes, plug each one in turn and keep pumping until the resin bleeds out the top hole. Plug the rest of the holes and start on the other side. When all is cured resume tapping for hollow spots.

luvitt · Jun 1, 2009

Ross said:
If you drill it and it is delaminated and not hollow, Then you can drill several holes and with a caulking tube filled with slightly thickened resin start pumping from the botton hole and as you fill the void the resin will start bleeding from the other holes, plug each one in turn and keep pumping until the resin bleeds out the top hole. Plug the rest of the holes and start on the other side. When all is cured resume tapping for hollow spots.

EXCELLENT Idea! will do. thanks

Ross · Jun 1, 2009

If it were mine I would disect it when the new rudder was installed. I just have to know why things go bad and how they were put together. I have done post mortems on just about every dead mechanical devise I have been able to get my hands on. Good luck with the new rudder.

DannyS · Jun 1, 2009

Foss Foam gave me a quote recently that was quite reasonable and they even said that if the rudder post and associated internal structure had not been compromised, they could re-use it and knock about a third off the cost.

Ross · Jun 1, 2009

There is a serious design flaw in the construction of rudders if there is a company that is able to stay in business building replacement rudders. There is very little more important to a sail boat than the keel and the rudder and both items get a great deal of print in this forum.

Richard Bryer · Jun 3, 2009

An old issue of DIY Boat Owner had an article in it on repairing foam filled rudders. Written by Nick Bailey of Bristol marine here in Toronto area. Probably helpful

BobM · Jun 3, 2009

If anyone is having a rudder scratch built, make sure specify it is properly constructed. If you look at the photo attached that is not how you want it built in my opinion. I suggest you carefully specify what you want.

Look how weak the stainless "finger" construction is. It is better than just a few fingers splayed out with no attachment but I have seen a photo of how the rudder was built on the Lancer 25 I owned and I would ask for this. It allows the torque to be transfered to the post by a weld completely down the stainless plate. The plate has holes to relieve some of the weight. There is little likelihood of the plate rusting a breaking off the post, as is possible with a weaker attachment to the post exemplified in the photo above.

Ross · Jun 3, 2009

There is no way to determine The relative strength of the two systems without knowing the details and dimentions of the material being employed. 1/4 x3 inch stainless steel bars welded to a sched 80 tube can be wrapped around the tube without fracturing the weld. The weak link would be the quality of the welds. I would be much more concerned with the method of joining the halves and filling the space.

How can you tell the rudder delamination is serious

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