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Discussion Starter · #1 ·
i wonder how well a simple 6 foot ply wood rudder would work. my boat has about 3 feet of stern, i was thinking about just taking a 18 inch by 6 foot plywood board sealed with epoxy with some sort of rudder hanger screwed to the stern. then a simple tiller that bolts on should work. it could be stored under a settee cushion. it might not be perfect but it would have to be better than no rudder at all and best of all cost under a 100 bucks

i could even shape like below to cut some weight, and bevel the edges

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Telstar 28
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You'd need some pretty heavy pintles and gudgeons to deal with a rudder that large.
 

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October Moon B43
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Unless you plan on crossing an ocean why worry about losing your rudder? The odds are probably a million to one in your favor anyway that it will never happen. Other than hitting a piece of debris you failed to spot the Chesapeake isn't going to deal you a dirty hand from weather conditions. Just get a membership to Boat US or Sea Tow and save the plywood for an other project.
Mike
 

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Or consider a catamaran.

2 rudders - a built in spair.

Whatever breaks, I plug-in an emergency tiller to the side that still works (ss pipe - very sturdy) and disconect the tie rod. If the other is bent hard over, there may be something required there, who can say.

Should the rudder tube rip out, there are 2 water-tight bulkheads in between it and the cabin.

Yes, I know cats have their weaknesses. Doesn't everything. This is a strength. I had 2 rudder failures on a prior cat, and neither required any more heartburn than sailing home.
 

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Discussion Starter · #5 ·
SD only about half of that would have been in the water.

as for crossing the ocean, the bag is a big place for a 1983 boat

as for the cat, can you loan me the money with 0% interest
 

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i wonder how well a simple 6 foot ply wood rudder would work. my boat has about 3 feet of stern, i was thinking about just taking a 18 inch by 6 foot plywood board sealed with epoxy with some sort of rudder hanger screwed to the stern. then a simple tiller that bolts on should work. it could be stored under a settee cushion. it might not be perfect but it would have to be better than no rudder at all and best of all cost under a 100 bucks

i could even shape like below to cut some weight, and bevel the edges

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****
****
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****
I have wondered about that too. I bet it could be done. I wonder if that would be prudent seamanship on fin/spade setups (like most production baots) before going cruising?? And would it be that involved to come up with a makeshift rudder?

Has anyone tried it?

- CD
 

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Telstar 28
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My plan would be to use a piece of plywood lashed to a boathook, and use lines run to the aft end of the makeshift rudder, to blocks on the amas to help control it.
 

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I have some concern about the adaquacy of plywood for this application. Remember, your carrying this in case your original rudder fails, so presumably there are some significant loads being applied to the rudder. Half the grain in your plywood rudder will run along the cord and contribute very little to the stiffness and strength. I think your going to have to strengthen the plywood with some form of reinforcement or use a solid hardwood.
 

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Farr 11.6 (Farr 38)
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Plywood rudders work quite well for pindle and gudgeon hung rudders with the alternating plys distributing the loads both vertically and horizontally. They should be shaped to get decent flow and beefed up above the waterline so that the torque is fully distributed into the foil. They do need to be sealed with epoxy and ideally with a layer of cloth.

For any sizable boat the rudder would need to have a thickness of roughly 1.5" (40mm) to 2.5" (60mm) thick. And there is the problem-properly engineered it would be extremely heavy and difficult to ship. Beyond that the pindles and gudgeons would need to be very sturdy and the transom beefed up to take the huge loads.

Jeff
 

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Telstar 28
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I agree, the stock rudder on my boat I believe is marine plywood. :)

Plywood rudders work quite well for pindle and gudgeon hung rudders with the alternating plys distributing the loads both vertically and horizontally. They should be shaped to get decent flow and beefed up above the waterline so that the torque is fully distributed into the foil. They do need to be sealed with epoxy and ideally with a layer of cloth.

For any sizable boat the rudder would need to have a thickness of roughly 1.5" (40mm) to 2.5" (60mm) thick. And there is the problem-properly engineered it would be extremely heavy and difficult to ship. Beyond that the pindles and gudgeons would need to be very sturdy and the transom beefed up to take the huge loads.

Jeff
 

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The plywood... but my boat is relatively small and light. ;)
 

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I think the longer ocean races now require the boat to have an emergency rudder aboard and to have mounted it under non emergency conditions, so more people have been thinking about the subject.

I have been eyeing the bottom of my pilot berth. It is currently made of 1/2 in plywood but if I upgrade it to 3/4 and reinforce it with fiberglass cloth and epoxy it would be solid enough, especially since at least 1/3 of its 6 1/2 foot length would be out of the water. I'd have to get some pretty heavy gudgeons and permanently install them and predrill the rudder for pintles.

It's on the "to do - (eventually)" list.
 

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Discussion Starter · #16 ·
my basic idea it to make it out of 3/4 ply ( with a glass layer ) the size of one of my settees for storage. then a handle which would bolt on, then slip in to some mounts on my stern which is 1 inch thick glass that i have 100 % access to for backing plates. it would not need to be off shore, just get to shore in the bay

i think i may do it
 

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Rudder Emergency

Marine plywood / epoxy would not be neutral buoyancy - although it probably wouldn't be of top concern in a lost rudder situation, Handling would be very different from a rudder with proper buoyancy.

The force on a hard over rudder at hull speed is measured in tons. Hose clamps and a boat hook attached to a barn door will be very exciting, and tragically, almost useless.

The best bet is to have safety straps (they can double as stops) external to the rudder. If it falls off, you can get it back.

Best Regards,


e

.::.
 

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Just to add another example of wooden rudders:

My boat a C&C25 has a solid wood laminate rudder. I say laminate because it is nothing like the plywood we might commonly think of. I have no idea how old this rudder is or who made it originally but it is made from a very hard deep red wood, perhaps Cyprus or Redwood. At the top (tiller end) it is 2.5" thick and tapers as it meets the water line. The leading edge is tapered as is the trailing edge. The trailing edge has a much wider taper than the leading edge to make it more of an airfoil. The layers of laminate wood are of varying thickness; (see photo). Where the laminates are tapered there is extra layers of glass cloth buildup as well as on the leading edge and bottom foot of the rudder. The whole rudder is encapsulated in a thick coat of epoxy resin.

I recently sanded it down to bare glass and re-coated it while I was replacing the gudgeons and pintels. I had to trim a small area of the rudder with a saw and was able to see the laminates very good in the cross section.
The rudder is very heavy for its size (about 5' tall) weighs 50lbs. I'm hanging it on a new set of Shcaffer transom mounted gudgeons and the pintels are 1/2 inch heavy duty custom stainless steel.





Just thought you guys may be interested.
 
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