DAMAGED RUDDER To Rebuild or Not Rebuild

Ted Andresen, #75

To save haulout time I pulled the rudder, prop shaft and Cutlass bearing housing out of the boat while it was still in the water. Then I pulled off the old rudder post and let the rudder dry in the sun for a few weeks.

I ordered the rudder stock from Jamestown Distributors (4'(?) of 1" SiBronze rod @ $20/ft) and took it to Admiral. They bent it to fit the rudder and drilled the holes for the three lower 5/16" drift pins and the 1/4" upper drift pin. It took them a few hours.

I think they charged me about $50/hr for maybe 4 hrs. I don't remember exactly because they were also doing work on my pintles and prop shaft.

Putting in a new rudder post is a pretty technical job. Assuming that the axis of the rudder tube is coaxial with the center line of the gudgeon holes, the tough part is ensuring that the axis of the rudder post is coaxial with the center line through the pintle tips. If this alignment is off by any significant amount, it would be put extra load on the lower end of the rudder tube and the lower rudder bearing. I worried about that a lot and took all sort of precautions to keep that misalignment to a minimum.

Even after I was all done, I had trouble getting the top of the post to sit in the center of the top of the rudder tube. I finally had to re-seat the lower pintle to get the alignment to work out.

In the process I added some bushing to the pintles. The were getting sloppy in the gudgeon holes.

For me, replacing the rudder post was an interesting but long technical challenge.

I would not build a new rudder. That is a HUGE amount of work that will take time from other work on the boat.

I would rebuild the old rudder by replacing the missing boards, filling any voids with epoxy and covering the entire rudder with multiple layers of epoxy and fiberglass.

Check the rudder post where it encounters the first drift pin. A good part of the 200 ft-lb (nom.) of torsion is delivered to the rudder through the drift pin at this point.

The 5/16" pin removes 40% of the load bearing material from the post at the hole. (A 1/4" pin would remove 30%.) This should not be a problem for the SiBronze rod. I don't know if it is common, but the smaller cross section at the drift pin caused my rudder post to develop a hair line crack on one side of the drift pin.

You might sand that area and examine it with a magnifying glass. If you see a crack, consider replacing the post. This alone is a big job.

Nathan, Dasein, #668

I have to offer the opposite opinion here. As the owner of a boat that someone glassed over the rudder, I strongly disagree with this procedure. In my case, there are several areas that have gotten chipped/cracked at sometime in the past. My boat has been out of the water for 2 years and the wood inside the glass is still wet. I'm going in the water this spring, so I guess I'm going to just repair those areas to prevent any more water from getting in, and just wait till the wood rots and I *have* to build a new one.... the point is though, that glassing over a wooden rudder can lead to some nasty propblems later on, if the glass ever gets compromised.

stephen

I am embarrassed to admit that I have forgotten the new owner's name, but he's up on the Great Lakes somewhere. Anyway, he has #140 (my previous boat) now.

Her original rudder was fiberglassed over in the 1980's some time. So there is a fairly long-term 'test' of the method for all those who may be considering it.

Ted Andresen, #75

Several people have mentioned rot while discussing their rudders. I didn't think that wood immersed in salt water could rot because the wood rotting fungi need fresh water to survive. A garboard strake will rot from the inside out because of rain water in the bilge, not because of contact with salt water.

The only problem that I have had with the wood in my FG'd rudder has been worms. The got in through an unprotected area near the pintle. I don't think that worms are found outside of tropical waters.

As for delamination, I haven't seen any. I dried my rudder in the sun for several weeks before I applied the glass with polyester, not epoxy, resin in the 70's. I think that polyester will bond to wood, if it done properly to dry roughed-up wood. The fiberglassed bulkheads in our boats are an excellent example of polyester resin bonding to wood.

Last summer I gave the rudder another coat of glass with epoxy after replacing the rudder post.

Mark Parker, #516, All Ways

I agree that added area at the bottom of the rudder is a good idea, but I heard it attributed to Carl Alberg as a Mark II design. Whichever, I did the modification to my rudder while is was working on it anyway and have been pleased with the results. I just added a piece of mahogany the right size/shape with lots of epoxy and long lag screws. It seems to be holding up well.

Jack

My bronze post broke at the bend where it was drilled and countersunk. A definite weak area. I watched the rudder float up Buzzards Bay on the current going to the Cape Cod Canal. The rudder is probably in Europe by now. After getting outrageous estimates from boat yards I was determined to replace the post and rudder myself.

I replaced the post with a 1" diameter titanium bar that provided strength and is lightweight. I traced the curvature of the bar and located the holes from another boat as I had no blueprints. A machine shop drilled the holes. A sheetmetal shop ( I forget the name) around Rockland, MA bent the bar. C.E. Beckman, New Bedford MA had bronze pintals in stock.

I made the rudder out of a sheet of 1/2" marine plywood. First cut the plywood sheet in half and fastened the two halfs together with west epoxy for a resulting 1" thick piece of wood. Then glassed over the rudder.

I removed only the propeller. With the boat on jackstands there was not enough height to insert the bar into the keel, so I dug a narrow trench 2 feet deep to drop the rudder in and the post easily was pushed into place. I replaced the packing, aligned the new pintals and screwed them on.

I dont know if all this makes sense or is the best way to do this job but it only cost a few hundred dollars and has been trouble free for the last 3 years.