rudder discussions

[Scott Galloway]

Ebb,

Actually I did make some videos of my self steering system, which feature studio narration and background music, I cannot post those on-line for various reasons. I have used two of them in some for the classes that I teach. I could potentially share one or more of those videos with you in a Zoom session.

However I built a web page devoted to the subject. The URL for that page is: http://www.solopublications.com/sailariq.htm
The photos are small to preserve band width, but the narrative explains how to build such a system. If you would like, I can send larger versions of some of the photos to you by e-mail.

Back to rudders, I understand your point. I merely wished to say thatI have not felt a need to alter the original location and/or design of tiller.

My motor is clamped on the riser (motor mount) in the lazarette, but the handle does not protrude forward through the small front hatch aft of the tiller post. By the way, I installed a permanent louvered vent in that hatch to promote air flow in the engine compartment. You can see the bottom edge of that vent in the photo that I posted earlier on this thread. Instead, the motor handle protrudes upward and slightly forward of the large to lazarette hatch. It does not interfere with the traveler or with the tiller in that position. If I choose to do so, I can close the hatch to rest open the end of the motor handle, but I usually don't. Of course I cannot close the hatch fully with the motor running. After I shut the motor down, I just fold the handle back and then close the hatch.

[Bill]

Outboard related post moved to outboard thread. It's there, but it's not showing in the thread heading for some reason.

[Hull376]

I'm making a replacement 3 plank rudder similar to the one on the boat right now (6" w 4/4 Honduran Mahogany). I've been practicing the construction using pine and a cool used ancient Dowl-It jig I found cheap on Ebay compared to the new ones (lots of bad copies being sold that don't work as advertised. Looks like a company bought Dowel-It, stopped making the old model which has been around since 1940s, and is now charging way more for newer models probably made in China instead of Michigan, and reviews of copies complain they don't center properly, cheaper parts, poor machining of parts) Thinking about 3/8 silicon bronze rod x 16 tapped, mated to 5/8" deep machined holes into the 1" rudder shaft (new straight shaft for my outboard model, and bolts with nuts extending well into board 2 from board 1 next to the shaft. Drifts will connect trailing board 3 to board 2. Drifts at opposing angles to prevent board 3 from loosening up from 2, except for small gaps due to wet/dry cycle) Lots of great info on wooden boat forum on how to do drifts the right way. Anyway, I have two construction questions:

1. This will be traditional construction. Mahogany + silicon bronze fasteners. No glue, no 3M stuff, nothing rolled on, painted on (except bottom paint), or squeezed on. Current rudder is 50 years+ old, and that's how its built. But to drill the longish holes for the fasteners, I still need to hold the planks together. Could use external straps screwed at the joints before drilling. Could use interior wood glue that would "dissolve" when immersed in the water. I want something that keeps everything in alignment during drilling, but want the planks to be able to move on the fasteners during wet/dry cycles, like my current rudder does. I thought of using clamps, but thy get in the way, won't work on the curved planks because I need to cut the wood to pattern to drill the opposed angle drift holes. What do you folks think about the two options I've come up with, or are there other options?

2. I'm worried about the alignment of the tapped machined holes on the shaft and my ability to get them aligned with holes drilled in the wood. I admit it: I have mediocre measuring and woodworking skills! If I'm off a smidge, it seems that I won't be able to slide the pieces together without introducing misalignment stress in the wood. So how to make sure that the pieces mate? With through holes in the shaft, I could always start the holes in the wood through the shaft, then finish with the Dowl-It on the rudder. But that kind of defeats the purpose of having "elegant". as ebb says, tapped holes only part way through the shaft, as Tim describes above. The other option I thought of would be to cut small threaded pieces of 3/8" rod, screw them into the tapped holes in the shaft, then align the rudder to the shaft and tap the shaft to leave some marks on the leading edge of the rudder. Am I over thinking this? I just don't want to find out that a hole isn't matched exactly to the shaft holes.

[Hull376]

Some pics of pine practice.

Makes a big difference in how you drill the holes. Wooden Boaters said to drill very slowly don’t use speed bits they wander off and make sure you don’t drill more than a few inches at a time without removing the wood chips. I tried drilling really fast just to see what happens and it doesn’t look very good! But going slowly removing the chips as they recommended gives you straight holes every time. They also recommend using a Dowling jig.

In the last photo the left two are drifts pounded into undersize holes and the right two are bolts. The holes are about 11 inches

[ebb]

Years ago I mailed to the Admiral what I thot is a simplified version
of making a full length, no prop cut-out, three-board rudder. It
used the rudder drawings in the Manual. Don't remember why it
wasn't useful. It used internal threaded rod tapped into the 1"
shaft stock. Plan could have been redrawn for a two-piece rudder
shaft.

Suggest using Honduras mahogany and Everdur, 655 bronze. Silicon
bronze is readily available, but, of course, we pay a premium price
for it. Original wood/bronze rudders lasted decades/years in and
out of the water, drying out, resoaking and working all that time.
I think using stainless in salt water is asking for trouble.

[Hull376]

Ebb, I’m building new 3 plank mahogany rudder similar to your old post. Will post pics eventually. But a question for you: what if anything to squirt in the tapped 3/8” x 5/8” holes in the silicon bronze Shaft when installing the threaded rods to allow them to be removed, but also to prevent them from backing out. Definitely not 5200! Pressure from tightening the nut on the outboard threaded end should prevent loosening, but as boards relax when drying on the hard takes off the stress on the shaft, they could loosen, but maybe not. Ive gotten input from the wooden boat forum on some aspects of my construction, but they don’t build rudders that connect to a shaft like ours. The designs seem to be mostly gudgeons and pintles.

[ebb]

Kent, have fun with the project.
Ultimate materials will be: All silicon bronze,
and Honduras Mahogany.
Since you are using s. bronze thruout, you won't
need to seal the holes. Apply a couple drops of
Blue 242 Loctite to the male threads.
If you are worried about water getting in, a wet
application on all the threads (but not the bottom
of the threaded rod) may make it difficult to
sheer the seal later.

Henkel has a Technical Data Sheet.
The product is made for disassembly..

[Hull376]

Thanks ebb. I use blue Locktite on my cycling shoes to keep the screws that mount the cleats from coming loose. Takes a bit of effort to remove them, but they do break free!

[ebb]

Kent, Thinking about how many threads you're going to get
in the blind 3/8" 5/8" deep threaded hole in the shaft. And
how many of them you will have that actually will be holding
the first two planks onto the shaft. Actually holding the
rudder together.. for all time. Daunting!

WHY NOT TO USE BLUE242
Your choices are 16 and 24 threads per inch taps. Even the
bottoming tap doesn't thread all the way to the bottom of
the hole. Let's say 1/2" max, with incompleat turns into the
curve of the 1" stock.

Maybe half inch will get you six full threads? Or 9-10 if you
make fine threads. I don't think any corrosion occurs in the
silicon to silicon connection. But the blade of the rudder
will cause some stress on the fastnings where they enter
the shaft.

Fine thread removes less metal than coarse from the 3/8"
diameter of the rod. You will be coving the edge of the
first plank where the wood meets metal. If you are
making the traditional 2 piece bent shaft model with the
opening for a propeller.. you have opportunity for even
less attachment of threaded rod to shaft.

You will be using nuts on the opposite side of the first
two planks of a three plank blade. I don't believe
H. Mahogany swells much when it gets wet. I somehow
believe the wood does not get very wet inside. the
cracks in a new rudder will for years be quite narrow
when the boat is regularly on the hard.
Of course I don't know this for a fact, just guessing.
But everyone agrees the rudder 'swells' up tight just as
regularly!

If you are imagining disassembling the rudder sometime
in the future, sliding a plank up 3 or four bolts will be
impossible, Sheering Blue242 bond using the nut end
will be just as impossible. I can not imagine the 3/8" rods
unscrewing themselves.
I'd more likely be using Tefgel or Lanocote to primarily
assemble the rods.. and drive them hard into the tapped hole,
down where the thread looses definition and the thread on
the rod deforms and hopefully creates a lock that way.

imco it is better to keep salt water out of the screw joint.
Ebb would probably use Tefgel -- slather the threads, but not
the bottom, so the rod goes in all the way.. whew!
__________________________________________________
Since I'm babbling here. and it's past 4am -- one last burble:
Why not get a toothpaste tube of 5200(!), 4200, Siklaflex
rubber and seal the wood cove to the bronze stock. This
may stop any drying out or swelling in this joint. And help
to keep the blade from moving at this juncture. Keep the
goop away from the rod joints. OR NOT ! !
You and I know It would be a big mistake to use rubber glue
between the planks..
Original bronze and H.Mahogany lasted fifty years hanging on
the end of a plastic boat. Very few were ever taken apart
for 'maintenance'. Attempting to seal/bond the wood to metal
joint, that IS the rudder, is futile.

[Hull376]

Ebb, I will go for 3/4” depth for machined holes. Probably have 8 good threads with 16 threaded bar. 24 threaded harder to find in silicon bronze 3/8”. I have 6 bolts, straight shaft (outboard) don’t think flex is going to be a problem. Some of the larger rudder designs may induce more stress at the shaft.

[CapnK]

Kent - I've just got to say "Goodonya" for undertaking such a project, and let you know I hope it comes out perfect. Salut!

Keep us posted, and like Frank always says "Mo' pics!"

[Hull376]

Thanks for the encouragement Kurt! I’m moving right along with this project and will post pictures when it’s about done. Not doing anything the next few days as this cold front is going to bring 15° or lower temperatures to Houston. Too busy bundling up the banana trees and palm trees right now! Say Bill, would you rather I posted the Rudder project on my boat page or put it here?

[Bill]

Your boat page would be more appropriate. Thanks

[Hull376]

Posted my mahogany rudder replacement in the Gallery: A—376 Afloat http://www.pearsonariel.org/discussi...6-Afloat/page3 It starts about halfway down the page.

[Bill]

THANKS for posting the link.