What's new

Making new style rudder for old style boat

wjejr

Active Member
I worked on the leading edge yesterday using a panel cutter to make the shape. I practiced first on piece of scrap, then the full size pine model and finally the mahogany blank. I took 3 passes on each side so as to minimize tear-out and create the smoothest cut. Next will be back to the sanding block and blend the leadin edge into rudder.

In case you were wondering about the router table setup, it is mounted in the extension table of my table saw, and that helps save space The red router plate allow you to raise the router up and down easily with the dial handle bottom right. Having this adjustment mechanism made staging the 3 passes simple. The fence connects to a vacuum hose and keeps the dust/chips manageable. The router is variable speed, so that I can run the router bits at the different speeds.
 

Attachments

wjejr

Active Member
I've got a couple of questions for all of you Sunfish experts out there, the first of which is, "Why is the rudder bottom angled in such a way that the trailing edge is higher than the leading edge?" Have a look at the attached picture. The blue line in the picture shows how the trailing edge is shorter than what I would have thought. A couple of possibilities as to why the designers did this have crossed my mind:

1. It lessens the possibility of damage when hitting/scraping/beaching the bottom as the trailing edge is thinner and weaker than the leading edge.
2. When the boat is moving through the water the bow lifts such that the rudder bottom is parallel to the surface of the water.

My guess is that it's the first, but I am interested in what others think and if any knows for sure (i.e. in literature or builder told them directly).

The next question is whether it makes any sense to deviate from the design and have the trailing edge longer?

As always, thank you in advance for your thoughts.
 

Attachments

L&VW

Well-Known Member
I've got a couple of questions for all of you Sunfish experts out there, the first of which is, "Why is the rudder bottom angled in such a way that the trailing edge is higher than the leading edge?" Have a look at the attached picture. The blue line in the picture shows how the trailing edge is shorter than what I would have thought. A couple of possibilities as to why the designers did this have crossed my mind:

1. It lessens the possibility of damage when hitting/scraping/beaching the bottom as the trailing edge is thinner and weaker than the leading edge.
2. When the boat is moving through the water the bow lifts such that the rudder bottom is parallel to the surface of the water.

My guess is that it's the first, but I am interested in what others think and if any knows for sure (i.e. in literature or builder told them directly).

The next question is whether it makes any sense to deviate from the design and have the trailing edge longer?

As always, thank you in advance for your thoughts.
Sunfish don't always sail in a forwards direction: backing in shallow water would increase the risk of rudder (and board) splitting.

 

wjejr

Active Member
I've been away, first on vacation and now on business, but I was able to make some progress on the rudder.

The next step was to start to create the final shape from the blank. I made the cut by first tracing the line onto the blank and then making the cut using a radial saw. I taped the back of the cut to minimized tearout. I also clamped the rudder so it would not move. Murphy's law kicked in and the angle of the cut caused the blade to cross over a screw that holds the table to the saw. I removed that and made the cut.
 

Attachments

wjejr

Active Member
wjejr do you sail where there are weeds?
Hi SF,

I live on the north shore of Boston. I usually sail the boat in Chebacco Lake which is shared between the towns of Hamilton and Essex. I also belong to a club in Gloucester, and I sail there occasionally.

Weeds aplenty in the lake, not so much in Gloucester, although I do have some fancy bailers in another boat that suck up saw grass left, right and center.
 

wjejr

Active Member
Home from travellin until 2nd week in April, so progress on the rudder continues. Here's the final fairing using the large block sander. The foils shape seems pretty good when you run your hand over it. It's tempting to try for perfection, but I think I've got it as "perfect" as I can.
 

Attachments

wjejr

Active Member
Hi everyone,

Back again. I'm making this up as I go along, but the next step seemed to be to cut the bottom of the rudder to size. After working so hard to get the foil shape right, I thought about keeping it a little longer, but then I thought about hitting the bottom with it, and I shortened it to the prescribed lenght. I made a test cut on the pine dummy to make sure the angle was right and then made the final cut on the mahogany rudder. I added tape to the top and bottom of the rudder to minimize tearout. Because of the foil shape, the bottom of the cut is not supported.
 

Attachments

wjejr

Active Member
Hi everyone,

The next step was to position the rudder hardware and then mark where the holes are supposed to be. I used welding clamps to hold the bronze hardware in place, as the clamps had enough tension to hold the pieces firmly. I then used the largest brad point bit that would fit into the holes to mark the center. I twisted the drill counter clockwise so that the bits would not dig into the bronze. I did the hole for the tiller attachment last.

Note that in pictures 1 and 2 it shows the hardware tight against the wood. After thinking about it a bit, I moved the pieces out by 1/8" so that the tilller can swing down to the rest plate on the bronze rudder head.
 

Attachments

wjejr

Active Member
Hello fellow Sunfishers,

Well, if it's worth doing, it's worth doing to excess. It's complete overkill, but I decided to use G10 tubing to line the gudgeioin mounting holes so that the threads of the screws never touch the wood. The theory is that the threads cannot scrape into the epoxy barrier coat I will put on later. If the screws cut through the barrier water could get under the epoxy and make a mess. Secondarily, it also prevents the hardware from compressing the mahogany. The screws would shear long before there would be compression of the G10.

I had the G10 tubing lying around from another project, so no added expense; just a little more time. You can cut G10 with a regular saw blade, but here I used a diamond saw blade to cut it. You will see the pictures show that I use tape before drilling. This helps to prevent tearout (bottom) and is also easier to see the marks of where to drill (top). In the last picture you will see the G10 tubing in place. I sanded the edges of the tubing so that it forms a slight indentation where the epoxy can sit and soak in. Nex step will be to shape the rudder head, but that can't be done until the rudder head is mounted in it's permanent position.
 

Attachments

wjejr

Active Member
Hello fello Sunfishers. A little more progress to report. After mounting the rudder gudgeons, I traced the top one and then created a curve to merge into the rudder shape. I then cut to the line using a bandsaw being careful to leave a little extra. Once that was done then I mounted a sanding drum in the drill press and fine tuned the shape. After that I clamped the rudder in a vice and sanded out any marks from the drum.
 

Attachments

wjejr

Active Member
Hi everyone, I had a chance to mount the new rudder on the boat. To me it looks pretty good. I did notice, and you can clearly see in the second picture, that the old style hardware does not mount the rudder perpendicular to the water line, but instead it angles the rudder down. A few posts ago, I was wondering whether to keep the angle of the rudder bottom as shown in the plans or cut it to be perendicular to the edge where the gudgeons are mounted. The perpendicular cut would have been the wrong move.
 

Attachments

L&VW

Well-Known Member
Hello fellow Sunfishers,

Well, if it's worth doing, it's worth doing to excess. It's complete overkill, but I decided to use G10 tubing to line the gudgeioin mounting holes so that the threads of the screws never touch the wood. The theory is that the threads cannot scrape into the epoxy barrier coat I will put on later. If the screws cut through the barrier water could get under the epoxy and make a mess. Secondarily, it also prevents the hardware from compressing the mahogany. The screws would shear long before there would be compression of the G10. I had the G10 tubing lying around from another project, so no added expense; just a little more time. You can cut G10 with a regular saw blade, but here I used a diamond saw blade to cut it. You will see the pictures show that I use tape before drilling. This helps to prevent tearout (bottom) and is also easier to see the marks of where to drill (top). In the last picture you will see the G10 tubing in place. I sanded the edges of the tubing so that it forms a slight indentation where the epoxy can sit and soak in. Nex step will be to shape the rudder head, but that can't be done until the rudder head is mounted in it's permanent position.
You're going to put this rudder in WATER??? :eek:

.
 

wjejr

Active Member
Hello everyone,

It's been awhile since I last posted, but I have been making some progress on the rudder. I decided to fiberglass the rudder to make the rudder a bit stronger and more importantly to give it more durability. The other factor was that I had never tried to have the glass "see-through" and was keen to try it. So the first step was the barrier coat. I use MAS epoxy as I like the two to one properties. I've used MAS resins as a barrier coat before, and my experience is the surface must be absolutely clean and the thinner the coat the better. Thicker coats for me resulted in too much sanding. Speaking of sanding, from here on I wet sanded using mineral spirits and Klingspor wet/dry sandpaper. Here are the pictures from the barrier coating.
 

Attachments

wjejr

Active Member
Hello fellow Sunfishers. After barrier coating in the last post, the next step was to apply the fiberglass. I used 4 oz. cloth that I purchased from Jamestown Distributors. I have used fiberglass before, but have never tried on a complex, at least for me, shape. I found that it was difficult to get the glass to lay flat when trying to lay it over a 90 degree edge (e.g. leading edge, rudder head edge). Maybe staples would have worked, but by then the cloth was already wetted out, and it seemed to be risky to try it then.

You will see in the picture that I used scissors to cut the partially cured (i.e. green) glass which made the job much easier.

I debated about whether this step was worth the effort, and although I am glad I gained some experience, if I had it to do over again, I would not bother.
 

Attachments

wjejr

Active Member
Hi fellow Sunfishers. Its been so long, I had a hard time even finding my thread.

At any rate, once the rudder was done, I had to make a new tiller since I wanted to keep the old tiller / rudder combination when I took my children sailing. That system has the original type wood extension which is shorter and easier to work with when I have a passenger.

For the new tiller I again used G10 tubing for where the screws go through the bronze straps.

One thing I noticed is that the rudder to tiller clearance varies depending on whether the rudder is up or down. I cut so that the clearance is minimal when the rudder is in its normal operating position.

I have included a couple of pictures comparing the new tiller with the last tiller I made and the tiller that came with the boat which is likely the original.
 

Attachments

Alan S. Glos

Active Member
I wondered how long it would take this thread to mention the early 1970s hybrid rudder with the solid head to prevent cracks and splits. This design allowed for the new spade shaped blade while still using the old bronze rudder attachment hardware. Here is a photo of one I have for sale. See the full ad. in the "For Sale" section of this Forum.

Alan Glos
Cazenovia, NY
 

Attachments

Alan S. Glos

Active Member
I wondered how long it would take for this thread mention the early 1970s factory issue hybrid rudder with the more modern spade shape blade with solid bronze top gudgeon to prevent cracks and splits in the wood. This allowed for a better blade without having to change the rudder attachment hardware. I have one for sale, see attached photo and see full ad. here in the "For Sale" section of this Forum

Alan Glos
Cazenovia, NY

p.s. I too have shop envy of wjejr's wood shop!
 

Attachments

Alan S. Glos

Active Member
True. I have seen some old style tillers where they doubled up the brass tiller straps. That and the solid gudgeon fitting would make a fairly stiff rig.

Alan Glos
Cazenovia, NY
 

L&VW

Well-Known Member
Hi fellow Sunfishers. Its been so long, I had a hard time even finding my thread. At any rate, once the rudder was done, I had to make a new tiller since I wanted to keep the old tiller / rudder combination when I took my children sailing. That system has the original type wood extension which is shorter and easier to work with when I have a passenger. For the new tiller I again used G10 tubing for where the screws go through the bronze straps.
In checking G10 (fiberglass tubes), I wondered if they made them in 2¼" OD? ('Didn't find any). :(

For the sleeving of old holes, I cut sections out of golf club shafts. They're tapered—and stainless steel, so you can cut one or two sections that fit perfectly. My latest golf club acquisition is graphite, which is strong, rust-free, a good size, yet can compress a bit. :cool:

What use are golf clubs, anyway? :rolleyes:
.
 

wjejr

Active Member
In checking G10 (fiberglass tubes), I wondered if they made them in 2¼" OD? ('Didn't find any). :(

For the sleeving of old holes, I cut sections out of golf club shafts. They're tapered—and stainless steel, so you can cut one or two sections that fit perfectly. My latest golf club acquisition is graphite, which is strong, rust-free, a good size, yet can compress a bit. :cool:

What use are golf clubs, anyway? :rolleyes:
.

Hi L&VW,

You can find 2 1/4" OD tubing at McMaster Carr with an ID of 2". It comes in 40" lengths that, depending on the application, runs anywhere from $35 to $140.
 

wjejr

Active Member
Those old tillers with those brass straps would flex so much in a breeze.
Hi Charles,

I generally sail in winds up to 15 knots and, while I am sure there is some flex, I have never noticed it. The length of strap that is unsupported by the either the tiller or the rudder head is quite small, so it doesn't seem to have a lot room to bend. I am sure the older one without the solid rudder head bends more, but even with that one I never noticed a problem.

When I sail, I am always thinking about the rudder load and tiller angle. I focus on keeping the rudder load to a minimum and the tiller straight. If the rudder loads up and/or it stalls I am dragging it sideways through the water, I sheet out and try to figure out what I am doing wrong (e.g. boat heel, sail trim, fore/aft gooseneck adjustment).
 
Last edited:

wjejr

Active Member
Hello fellow Sunfishers,

The next step was to attach the rudder hardware to the rudder. I waited a couple of weeks for the varnish to harden up so that when I slide the hardware on, they would not scrape off the varnish too badly.

During the epoxy/glass part of the process, the holes had been filled with epoxy so they needed to be drilled out. Once that was done, I ran the screws through, put the nuts on tight and then used a hacksaw to cut the screws to length. I then filed the screw ends flat and later backed them out and beveled them very slightly with a hand powered grinding wheel.

At some point, I will wet sand the whole thing again, but for now the rudder is done.
 

Attachments

wjejr

Active Member
Hello fellow Sunfishers,

I attached the tiller to the rudder a couple of weeks ago, and the tiller was just sticking way up in the air (Picture #1). To correct the height (i.e. lower) I used a dado stack and trimmed the underside of the rudder. After epoxying the trimmed out section, I then glued (spray adhesive) a piece of 1/16th" cork to the underside as a cushion. I then, drum roll please, actually went sailing with it. Unfortunately the cork wasn't quite thick enough, and the wing nut on the spring-plate put a nice gouge in the bottom. No matter. I removed the piece of cork and replaced it with a piece of leather. That seems to have corrected the problem for now, and the tiller height works well with the extension when holding the tiller in one hand, sheet in the other draping back to the hand holding the tiller.

There is also a picture that illustrates how I mounted the tiller extension connector.

Hope all of this helps someone in the future.
 

Attachments

wjejr

Active Member
Hello fellow Sunfishers,

I have been using the new rudder now for a few weeks. To be honest, I cannot tell much of a difference, certainly nowhere near the difference the newer daggerboard, but I have not tried sailing for 20 minutes and then going back to the older board. It seems to cut the water cleanly, no chatter, but I never spent a whole lot of time looking at the original, no chatter there either, so who knows? Hopefully I will have a chance to compare the two rudders before the season ends.

For anyone who wants to try this, here's what I learned.
  1. Laying out the lines on paper full scale allowed me to visualize what the board would be, and I spent a lot of time working on the angles.
  2. Likewise the full scale model in pine was of huge help in setting up all the cuts.
  3. Using the stack dado worked well for creating the rough foil shape. Controlling the cuts was difficult, and I used marks on the fence and board to know when to stop cutting. Here again the full size model was invaluable.
  4. I tried lots of tools after that to refine the shape. For me the most effective were a #2 hand plane, spoke shave, rasps, a #92 Stanley shoulder plane and sanding blocks. If you don't have all of those, then any hand plane that is sharp will likely do, along with a rasp and sanding blocks. It may just take longer.
  5. The leading edge I cut using a router table and a panel raising bit. I could have done it with just the hand plane and sandpaper, but I had the bit/cutter so why not?
  6. Final fairing was done with a rubber automotive sanding block. Be careful not to take off too much.
  7. I recommend using the garolite tubing for the screw holes for the rudder hardware. The extra $10 worth of tubing guarantees that the screws won't cut through the final finish and let water in. You don't want that after putting all the time into this project.
  8. I used a barrier coat with MAS epoxy. Most people like West, but I prefer MAS as the mixing ratio is 2::1 whereas West is 4::1. I'm not so clever, and its harder for me to mess up the 2::1 ratio. Whatever you use, make sure the surface is clean and you brush on a thin coat only.
  9. I covered the board in 4 ounce glass, but if I ever make another rudder I won't bother. Trying to get the glass to lay properly on a small object with multiple curves and some sharp angles was not easy, and I don't recommend it. Just be careful with rudder and you won't need that extra protection.

Again, I hope someone down the road finds all or part of this helpful.

If I ever get around to taking pictures of the rudder on a windy day, I will post again.
 

Attachments

L&VW

Well-Known Member
I always give mine a airfoil shape just because. If you want to go all the way, leave the
trailing edge squared-off. With a rounded trailing edge there is flow separation about
two-thirds of the way towards the rear of the rudder on each side. With a square trailing
edge you get a vortex bubble that delays the separation.
Hopefully, you will not get vibration.

There is one of those old bronze brackets on Ebay. Personally I'd put the money towards a new style bracket.
A buddy has a pristine Viking [clone], whose rudder is different from others I have seen.

How does its overall shape, size, and edges fit with theories of hydrodynamic contours?

Fullscreen capture 10262017 63046 PM.bmp.jpg

The gudgeon is also a different design. Next July, I'll get close-up pictures.

.
 

Webfoot1

Active Member
Factory's built these with cost of manufacturing in mind first. Good enough to perform adequately, cheap to manufacture. Cut, belt-sand the edges and finish. If you look at the Sunfish racing rudder you'll see something designed for performance based on hydrodynamics but it will cost you much more.
Good thing is it's dirt cheap to experiment with you own designs if you want to. Would like to see a original Sunfish racing against a couple different type clones for fun.
 

beldar boathead

Well-Known Member
If you look at the Sunfish racing rudder you'll see something
designed for performance based on hydrodynamics but it will cost you much more.
.
the Sunfish composite rudder is no different in shape than the wood rudder. The daggerboard is quite different however.
 
Top