Plastic Classic Forum

Does anyone have details on fitting a rudder shoe to a Triton?

I'd lay odds that James/atomvoyager can answer any Q's you have on that... Is there a specific issue you are wondering about? I know a little, but James knows a lot more.

Hi,

My Triton Dragonfly does not have a rudder shoe and I am considering adding one to strengthen the rudder during its current rebuild.

I don't know if it was due to rot or grounding but both of the pintle mounting locations on the rudder were replaced by wooden blocks epoxied on to form new mount locations. Is common for the original wooden Triton rudders to rot around the pintle mounting bolts?

The plank the pintles are bolted to is held on by four long bolts which squeeze the rudder planks together. An inspection of the rudder showed that only one (second from the top) was effective. The top bolt was missing its nut, the third down was missing altogether and the lower bolt was cut. None of these bolts were supporting the epoxied pintle mounting blocks!

The Ariel and Alberg 30 use rudder shoes and this seems stronger to me than the pintle and gudgeon set up on Dragonfly.

Has anyone fitted a rudder shoe to a Triton? Any advice on strengthening the rudder would be appreciated.
I am thinking of building a fiberglass rudder with air pockets to make it close to neutrally buoyant.

Ken Owens, B.S.G.
(Bottom Sanding Grunt)

I rebuilt my Triton rudder using two pieces of 3/4 plywood, fiberglass on top and off the shelf stainless pintles and gudgeons while in South Africa in 1996. Bronze was not available and converting to a shoe at that time was too complicated. I know stainless is prone to corrosion underwater but I epoxied them over and they've been good since.

The Triton I'm working on now in our backyard shed has a glass-covered plywood rudder with shoe instead of pintles and full length stainless shaft built by the previous owner about 8 years ago. It is somewhat overbuilt which is good so that you don't have to worry about stainless corrosion reducing the strength for many years to come. It had a lot of bolt heads, nuts and zincs protruding that made keeping the bottom clean difficult so I fared it in and sealed it under epoxy so that there are only slight gradual lumps where the fasteners are. I know it's not ideal to bury hardware and fasteners but the alternatives seemed worse and I haven't had a problem doing this on my own boat.

Here's the photos of the previous owner's work. The last one shows the hardware fared over and you might be able to make out that he added a semi-circle of stainless rod to the rudder shoe to prevent trap and fish net lines entangling in the gap. I have a flat plate on the bottom to do the same on my boat. On my boat I shortened and raised the bottom of the rudder about two inches so when going aground there is less chance of damage.

If you still have an inboard engine then you need a different design more like the original but you can still add a long pin to the lower end and fit a shoe. The Alberg 30 has a shoe and one set of pintles midway, which is good to reduce the loads on the upper and lower ends. If you don't do that then you may need to reinforce the upper end where it passes into the cockpit and have a sturdy bushing there.

The other photos

Hi James, Thanks for the reply.

Dragonfly has an inboard Yanmar and I would like install a shoe as in the last pic. I am leaning towards the Alberg 30 design with pintels in the middle and a shoe on the bottom. Any idea on where to find the shoe and pintels? I have looked but without success.

The link below shows an example of an Alberg 30 rudder rebuild. www.alberg37.org/Project%20DB/Reed-Rudd ... roject.pdf. Yesterday, I bought one of the shown pipe benders for $114 bucks at Harbor Freight and believe that I can bend a continuous bronze rudder shaft around the prop opening.

This link mentions that their new rudder ended up weighing 200lbs!! I like their fiberglass design. It won't rot. If I go that way, I would include voids to make it light and neutrally buoyant and use a continuous rudder tube.

Thanks again for any advice,
Ken.

There's no need for the expense, trouble, and weight of a continuous shaft bent around a prop aperture. You can try it of course. I doubt I could get it perfectly straight on its axis with so many curves. Glass over the bronze frame or glass-covered 1.5" plywood is more than strong enough without a continuous shaft. If worried about rot you could scale down the ply to say 1" and add more glass so that the ply is more of a spacer than being used for it's strength.

The center pintles on the A30 are two haves that join. Not sure where you can find pintles and gudgeons and shoe of the right size. You might try the old A30 forum or A30 facebook site for info. Otherwise, you can get a local metal fab shop to fabricate something out of welded plates and pipes as was done on the Triton I'm working on. If the pintles become too complicated to fit then just ensure the upper and lower attachments are extra strong and you'll be alright.

The A37 fiberglass/bronze type rudder is a nicer result but looks complex and expensive. You can scale it down to Triton size and do something similar if you feel up to it. I haven't tackled one of those myself so not much I can add. By sealing the plywood well you can also have a successful result with stainless, ply, and glass.

Thanks. I'll post pictures of my progress here.

Hi,

This is the current state of Dragonfly's rudder. You can see that wood has been replaced under each pintle and on the trailing edge by previous owners.

Ken.

I propose to make a new fiberglass rudder of the same shape but with an internal full length bronze rudder shaft shown by the green tape. The wooden pieces laying on top represent welded on bronze supports. I bought a pipe bender to shape the bronze and plan to build Alberg 30 type pintles and rudder shoe. During layup, the rudder tube will be clamped to a piece of angle iron to guarantee alignment. I have never built a rudder. Any comments appreciated. Here is the proposed layout.

The 'W' shape of the shaft seems really ambitious. To make life a bit simpler, I would forego the the flats inboard on the rudder. But maybe that would be too much of a bend on the shaft, to go almost 90 degrees to head back to the leading edge.
I'm very curious how this will all come together. I have a strong suspicion that my '71 Wanderer has a factory rudder. I'm sure it is long due for a replace and have been wondering how to deal with mine when it comes time.

I like to keep the bottom of the rudder about 2 inches above the keel to reduce the chance of damage when grounding. I suppose if you don't get the shaft angles right you can cut it at the second or third bend from top and from bottom and install as two pieces and rely on the strength of the glass. By using plywood it has enough strength for reduced shaft bends and less glass but since you apparently want to avoid any chance of future wood rot then the glasswork needs to be heavier.

Hi James,

Thanks for the reply.

I ordered a rudder shoe that will keep the rudder a few inches above the keel bottom as you suggest. It's for a Pearson Ensign but the dimensions seem right. I will have turn the end of the rudder shaft down to 5/8". I'll post some actual numbers when it arrives. https://shop.ensignspars.com/products/r ... hoe-bronze

Thanks for the info about plywood and glass. My design is bouncing back and forth between two. I could still layer plywood as you did for Atom and carve out room for the shaft in the interior of the rudder. How is the rudder shaft on Atom attached?

I also found a drawing of a rudder gudgeon for an Alberg 30 http://www.alberg30.org/maintenance/Steering/Gudgeons/ I think it will work with some modifications.

For example my Triton Dragonfly has a 1" rudder shaft not 3/4" as in the drawing. Would you happen to know he width of the Triton's keel just below the prop aperture? The drawing suggests 1 and 5/8" but my rudder is 1 and 1/4"; Dragonfly is in Florida and I'm in California.

Thanks, for all the help.
Ken

All the Tritons I've worked on have a 1" rudder shaft. 1 5/8" - 1 3/4" keel width is about right. When I use two pieces 3/4" ply plus glass on top it comes out right. Then the layers of ply make it easy to taper it down to about 3/4" at the aft end. Atom has two stainless pintles and gudgeons larger but similar to original and original bronze shaft. Because I filled the prop aperture and glassed it over it has some added strength in the shaft to rudder joint.

Hi Everyone,

The rudder shoe for my Triton showed up. It is for a Pearson Ensign but it looks like it will work. The width of the shoe is 1 and 5/8 inches near where the rudder attaches and the angles look right.

I am now leaning towards a glassed over plywood laminate as suggested by atomvoyager. My design follows Spur's boat book on page 54. The attached image shows a mock-up of what I have in mind; the green tape represent the bronze shaft and welded ears and the wood slats represent gudgeon straps; when sandwiched between layers of plywood, the ears will keep the rudder shaft attached.

If you guys like the design, bending the shaft is next. At 8:46 on the video ( https://www.youtube.com/watch?v=sR6OUHG2CTE) the guy bends a bronze shaft with heat. I think it's 1 and 1/8 inches in diameter. Think I might try something like that.

Thanks for all the comments.
Ken.

Also, I propose to remove the two inch strip of rudder along the line drawn to protect it from grounding.

That shop does some nice work!

Most boat owners get "Twofootitus".
Not us aft-hung rudders types, though.
We get "Twoinchminus".

Hi Guys. Solid Mahogany costs the same as plywood at my location, so I decided to make the Triton's rudder core from it. I was wondering if anyone has any idea about how to scarf the boards together. I was going to join the larger board to the full length bronze rudder stock with long carriage bolts and epoxy the rudder tip on with a tongue and grove joint. Finally, I plan to glass it for protection.

Some ideas:

Looking at what you've got there I would think to go tongue and groove *and* also use dowels to maximize use of the width of the mahogany, basically losing none that way.

Back in the day when I worked on surfboards, on ultralight blanks we used to dig out a narrow band of foam alongside & either side of the central stringer and lay fiberglass rope into that to create a sort of an I-beam. This was under the deck & bottom laminates of 4oz cloth.
You could possibly do the same, carving several slots into the mahogany maybe 1/4" or 3/16" deep, and say 5-6 inches either side of your join, lay in the rope and then sand it back smooth prior to glassing, either as the way to do it, or as a way to strengthen it in addition to glue/dowels/tongue and groove.

Or countersink some straps of metal or G-10 on both sides...

Going to be interesting to see how you finally do it.

Hey CapnK. Thanks for the suggestions. As for dowels, what do you think about extending three of carriage bolts to go all the way across the rudder? You can see their rough placement indicated by the black marker drawing. I will have to make them out of 3/8 rod since I couldn't find any 21" long.

I bet that'd do the trick too! Might be the best way to do it, even.

To test the rudder design, I am building a the test/practice rudder and could use some advise. The test rudder is made from two mahogany boards joined by an epoxied tongue and groove joint. The test rudder shaft is made from pipe bolted through both boards. All hardware in the final rudder will be silicon bronze. Should I use these bolts as with the original Triton rudder or do you think external straps welded to the rudder shaft would be stronger?

Bolts should be strong enough as on the original factory rudder but welded tangs are stronger because of more surface area attached farther from the centerline on each side.

Thanks! I want to make it strong. I'll weld on some steel straps for practice. Might need a pro to weld the bronze.

I may have misunderstood that your question was not related to the test piece instead of final design. A TIG weld in 316 stainless is strongest option. That may not be the case with welding or brazing bronze. You'll have to do some research there.

Thanks. My test rudder is made out of scrap steel and lumber so I can practice. I have already purchased a bronze rudder shaft for the final project which I plan to run the entire length of the rudder and insert it in a shoe. I would need to weld bronze straps to this. The pro in the video I posted welded bronze straps to a rudder post. Also on the youtube channel, Acorn to Arabella, they welded bronze floors for their wooden boat which seem really strong. The only other video I could find on actual bronze welding is at https://www.youtube.com/watch?v=iHpjdz85WpU All the others deal with brazing. The machinist I work with wasn't thrilled with the idea of bronze welding.

I was going to ask if the welds would be exposed to water, and if that would be a problem (assuming if bolts, then they'd be covered by glass), but if the straps are silicon bronze, I don't think they'd be affected by much.

Then again, I'm no metallurgist. Nor have I stayed at a motel recently.

Warning - thread drift:
I know that they are making things like Formula 1 driveshafts of carbon these days, and they have impressive strength. If not too highly priced, could this material be a way of making rudder shafts that can be metal-free? A quick look around found a 47" long, 1.25" diameter carbon fiber tube for $64US. That's a lot cheaper than silicon bronze, and us backyarders don't need to know welding or have the gear to do it...?

Carbon v Steel driveshaft, failure test:
https://www.youtube.com/watch?v=hjErH4_1fks

Cool Video! Maybe on my next boat I'll use carbon fiber!

Below is a pic of my final test rudder with a welded strap. During buoyancy tests, it had positive buoyancy before I tapered the trailing edge. After the taper and adding one layer of 1708, it is nearly neurally buoyant and very strong. I found a tig welding pro who will weld up the final metal work in bronze. I plan to keep the bronze on the exterior of the rudder for ease of repair. Next I will begin to bend some practice rudder shafts.

Thanks everyone for the advise.

Looks great. Very promising. Where do I put in my order for my rudder rebuild? <grin>

Thanks. Hope Mira's rudder is in better shape than Dragonfly's.

My rudder shoe and stock are bronze. Should I connect them bronze on bronze or use a bushing? Thanks

I have made a jig for bending the full length bronze rudder stock. The first test bend with 7/8 steel rod was successful. You can see the bent shaft laying on the old rudder. Note the old rudder shaft is not true near the top and it is misaligned with the new shaft. What do you guys think?

Looks like you have the bending sorted out. As to alignment maybe the old rudder and shaft were slightly misaligned or they were different angle because the keel groove and upper fiberglass tube are out. Either way, I guess you can tweak the bend to fit the boat or adjust the pintles and gudgeons for best fit.

Thanks. Never thought about the boat being out of alignment.

The aft edge of the rudder shaft has been rubbing on the rudder tube as if the rudder was being pushed aft under way. This may account for the forward bend in the old rudder stock. Have you ever put a bushing on the rudder stock just where it enters the hull below the waterline? This would eliminate this movement.

Thanks much for the comments.

I've never bothered to add a bushing at the bottom of the rudder shaft tube because I had one not far away at the top in the form of a short PVC tube under the rudder cap and flax packing. You could add it if you want but it's one more friction point and alignment point to worry about and it makes for less area available for the inevitable small misalignment. I doubt the rudder is deflecting much underway between the upper pintle and upper bushing. Rudder assemblies are seldom perfect so you will often see some side movement between shaft and tube and leading rudder edge and keel as you turn the rudder. You can use a string to check rudder tube alignment relative to the keel and to the pintles pivot point.

After all this work you may want to add some glass/epoxy to the shaft tube inside the boat. Not that it is a weak area but to add stiffness in case of a hard grounding that damages the rudder isn't likely to sink the boat. I didn't do it on mine because the tube is within a watertight locker.

Thanks. The rudder tube on Dragonfly is unsupported. Below is an image. At the top of the rudder tube there is only a Delron bushing with rubber o-rings. I will strengthen it as you suggest when I get back to the boat. What suggestion might you have for the location of a waterproof locker? Perhaps I could seal the rudder shaft in its own compartment? How is it done on Atom?

You can see how I sealed off the tube beginning at 4:30 in this video:

https://www.youtube.com/watch?v=1sTHd_nCyLg

It may not be so easy for boats with an inboard engine unless you can route the plumbing and cables clear.

Thanks. I like the added buoyancy, and security provided by the watertight lockers. Perhaps I could add them but have large watertight access hatches port and starboard for engine access. Exhaust plumbing etc. is an issue but sorting it out seems like the right thing to do.

Hi. I cut up an old bed frame and attached it to my pipe bender making a press to bend the bronze straps for the rudder. I also made a die to press the straps into by bending a piece of steel. I have been practicing on bits of aluminum. At first the bender warped the straps. You can see it in thinner the piece in the background in the image below. It splayed out the fingers. When I straighten out my jig, it fixed this issue as shown by the thicker part in the foreground. The 1/4 inch plate used for this last bend required heating or it would break. What about 1/4 inch bronze straps? Should I heat them? I don't have much bronze to spare for testing. The pro in the "Working on a Woody" video above did not seem to use heat.

Hi. Cold bronze test strap bent well except for a slight bow which you can see running vertically on the left side of the freshly bent strap in the attached image. The surface of the bend also developed a slight "orange peel" texture from stretching. Do you think heat would help reduce these effects?

Heating until it just begins to turn red makes metals easy to bend but I don't know if it does any harm to your bronze alloy. In stainless I know it can adversely effect the corrosion resistance properties. Maybe take it to a local metal fab shop for an opinion. Or there may be some fabricating forum you could ask.

Hi. I am trying to decide on the rudder strap/gudgeon layouts as shown in the pics below. I plan to install a lower rudder bearing and a shoe and either one or two Alberg 30 style gudgeons. Either 4 of 5 straps. To match the neutral buoyancy test I should use one strap per foot, ie 5. The small elbows represent the gudgeons. If you look closely you can see the outline of the full size rudder lofted on the paper. Also you can see that I bent the first and longest strap using a little heat. Any comments would be appreciated.

IT CRACKED!! As I was doing the third and final bend, the rudder shaft cracked! The bend that cracked is located at the factory bend on Triton rudders. I started bending at the bottom to accurately place the machined end as accepts the rudder shoe. The first two bends went ok. FYI this played out just as the experts foretold. Atom voyager suggested it would be difficult to keep this shaft aligned. I was tweeking this alignment when the shaft cracked. The machinist from "Working on a Woody" video said that sometimes bronze cracks if you heat and bend it, even though that is what he did! Back to the drawing board. I won't be attempting a bronze repeat. It costs about $400 a try for the bronze and machining.

Sorry to hear that. looks like you'll have to revisit the design. I sent you a PM with my phone number in case you want to discuss some design options.

Thank you James. I will contact you next week. Ken.

Here is a design idea. Instead of bronze, use a stainless steel shaft with only two bends. Weld three stainless plates as shown. No rudder shoe. Instead, pintels will bolt through the lower two plates. The whole thing will have a fiberglass skin over a foam core.

At least strong welds can be made in stainless.