Does this part of the gudgeon do anything?

JosefR

Member
What is the thumbscrew for? The other end is bolted down...manuals only show newer versions.
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Although long thought to be merely decorative, this is an important part of the original sunfish rudder system. The “thumbscrew” is actually a wingnut. Hopefully it is at the end of a long carriage bolt. Do you have the rudder that goes with this?
 
Yes, I meant wingnut. I have the original rudder and it fits fine. I am reading the Sunfish Bible and I think he said something about that letting the rudder kick up and to tighten the wingnut as hard as you can by hand, but I can't imagine how when it's a slab of steel bolted down on the other end. I don't know for sure if this thing is what he was talking about, there are no pictures.
 
That is what he is talking about. It’s not steel or it would rust. Someone else will know what it is made of - I haven’t seen one in years. It’s likley brass. Anyway it’ll bend some when you tighten it to the max. If it’s loose the rudder will pop up too easily. Also, for it to work right, the carriage bolt must be in a plastic tube to keep it centered in the groove in the hull.
 
That sounds like it might be sacrificial? I haven't heard anything about a plastic tube. The groove is not much bigger than the bolt itself. I guess I'll find out eventually.
 
If you don’t have the tube and your rudder starts unexpectedly popping up on windy days, you will be buying a tube ASAP. This rudder system is not the best, which is why it was replaced back in 1972.
 
I don't even see anything like that for sale from them.
And to make one, it would have to be the size of an ink pen tube...
 
Don't worry about the plastic tube, it's long gone on most all of the boats and has
nothing to do with the rudder popping up. Tightening the wingnut pulls up on the
bottom strap and makes it harder for the rudder to pop out. The plate on top is
a spring plate that lets the bottom strap 'give' if the rudder hits something. The spring
plate is angled upward by sitting on top of mounting screws. If the spring plate is
sitting flat on the top grudgon it will not do its job. I made a plate from hardware
bar stock and it worked just fine. Personally it's much worth it if you can find
parts for the newer rudder.
 
In fact the plastic tube has quite a bit to do with the rudder popping up. It keeps the piece on the bottom of the hull centered under load in high winds. Without the tube the carriage bolt shifts to leeward along with the bottom plate, and that small misalignment is enough to make it easier for the rudder to pop up.

However, getting the new style rudder is the best approach.
 
There is lots of neoprene tubing listed on the web you can use.
I never had trouble with the strap shifting, it was mainly the pocket
in the lower strap lost the edge needed to keep vertical piece from
popping out. Anyway the whole unit only worked good when it was
new from the factory. I think I got lucky finding a aluminum rudder
cheek on Ebay for a decent price. It would be nice if someone could
turn out a plastic rudder cheek unit using their Home Deposition Machine.
If it was a commercial machine it would also have the resolution to
make DePersa drain plugs.
 
To add to what has already been said. this item is a 7 1/2" long by 1/4" dia. bronze carriage bolt with a wing nut on the deck plate end. Its function is to tension the rig to keep the rudder in the "down" position but not so tight as to prevent kick-up if the rudder blade hits a submerged object. The plastic tube that surrounds the bolt in the recessed fiberglass notch is important as it keeps the bolt in alignment. Any good hardware or plumbing supply store sells tube like this in bulk that will replace the factory issued tube.

This rig works like early downhill ski bindings. Too little tension and the rudder kicks up when you don't want it to; too much tension and the rig does not kick up when you hit an object and the rudder blade is damaged. The post 1972 rudder rig is a big improvement over this original rig, but the old rig works if you find the "sweet spot" for the wing nut tension.

Alan Glos
Cazenovia, NY
 
I have a 1971 Sunfish, and I am happy to report the rudder hardware works exactly as it should 45+ years later. I fully expect that I will give out long before the rudder hardware does. What did give out however was the backing block as it had begun to rot and was not installed correctly as the factory. I replaced that.

Looking at your photo, the top and bottom bronze pieces looks just fine, and you should have no trouble with them. One thing to check though is the screw that holds the bottom piece in place. Make sure it is tight and the backing block has not stripped. If it has, you can fill it with epoxy and wood flour (or very fine saw dust) and then re-drill it.

As Beldar B. & Alan have stated, the tube is critical to restrict lateral movement. Don't go sailing without it. If you stop and think about it for a moment, it is obvious the tube is important as the stern was molded specifically for it.

The tube on my boat deteriorated to the point that it crumbled and so needed replacing. My hardware store didn't have the right tube, but I was able to find it online at McMaster Carr. I will measure and report back if different, but I believe the tube is white nylon 3/4 OD 1/4 OD.

On how tight the wing nut should be, I keep mine tight, but not anywhere near as hard as I could. Instead, and as I have mentioned in other posts, I work hard to keep the tiller load low by keeping the boat flat and adjusting the gooseneck for high wind. In really high winds I might tighten the wing nut more.
 
The smallest width of that groove is maybe 3/8", no way a 3/4" tube would fit in there. This is the closest thing McMaster Carr has that might fit.
Flexible High-Pressure Nylon Tubing, Semi-Clear, 0.225" ID, 3/8" OD $9.85/5 feet + shipping.
Not questioning the importance of this thing, but if it's so important, you'd think Sunfish would have it available in the 6" that I need for a buck...guess I'll have to start visiting hardware stores.
 
The Sunfish manufacturer hasn’t stocked parts for those old rudders in 20 years I bet. Don’t feel bad as the company that currently makes Sunfish is pretty clueless and doesn’t stock parts for new boats either!
 
I had $150 worth of parts I need in my basket there, but they don't answer the phone and Intensity seems to sell the same stuff for a lot less, so I just went with them instead, saved about $50, assuming the mast caps and such are the same. The guy at Intensity says they will. We'll see.
 
My next-to-the-latest Sunfish (#4 of 5) came with this tube. That Sunfish is located a six-hour drive from where I am now, so I can't tell you what it's made of—but this is what it looks like:

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The wing nut adjusts the tension on the vertical plate that attaches to the rudder blade. We leave the wing nut loose while we install the rudder pin, then tighten it so the vertical plate is snug into the notch on the keel plate. That top plate is called the spring plate, and there is a little hump under it on the deck plate that gives it room to flex down like a diving board, which in turn lets the bottom of the vertical plate pop out if you hit something.

Here's a picture of the carriage bolt tube.

Alcort Super Sailfish MKII rudder carriage bolt tube.jpeg
 
The smallest width of that groove is maybe 3/8", no way a 3/4" tube would fit in there. This is the closest thing McMaster Carr has that might fit.
Flexible High-Pressure Nylon Tubing, Semi-Clear, 0.225" ID, 3/8" OD $9.85/5 feet + shipping.
Not questioning the importance of this thing, but if it's so important, you'd think Sunfish would have it available in the 6" that I need for a buck...guess I'll have to start visiting hardware stores.

Hi JosefR, Yep, I guessed wrong. The tube is 1/2" OD x 1/4" ID x 5 1/4". The tube as i recall is not totally recessed in the groove as I recall and the 1/2" OD should fit. I just looked at the McMaster site and the stock number is 8628K27. The price is $11.09 for 5' When I bought mine they sold it by the foot.
 
A little trivia, new skippers think that the number on the rudder hardware is a serial number. 2,675,775 is the Patent Number.

Alcort Rudder Releasing Mechanism Patent page 1.png



Alcort Rudder Releasing Mechanism Patent page 2.png
Alcort Rudder Releasing Mechanism Patent page 3.png


And a tip, I would not attach the horizontal pivot pin (rudder pin) to the deck with the keeper chain, the pins tend to disappear during trailer trips or storage. I have started attaching the keeper chain to the side of the rudder blade. Other options are to remove them for storage and transport or tape them securely. Same thing if the mast has the eyebolt and block at the top, and watch for any deformation of that eyebolt, it could be chrome plated brass and if it is, it is better to change to the new style plastic fairlead cap.

Cheers
Kent and Audrey
 
Ok, I got the tube added and while I was pulling on stuff, the two screws holding the wingnut plate down came out. Probably would have come out while sailing if I hadn't done it. Can I add an inspection plate here so I can add a backing plate under it? Don't know if there's foam in the way. And is there already something under the bar that I will have to remove, like an old backing plate?
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You have it correct, you'd just have to dig out some foam. Before doing anything I'd
do a little research and see if it's worth it for you to install the updated rudder system. If
so the inspection hole would be moved rearward over the screw holes securing the
gudgeon plate. If you could get someone to sell you the rudder cheeks for about
$45 I'd say update it. The rest of that parts are not that expensive if you don't mind
making a few wood shavings.
 
"Can I add an inspection plate here so I can add a backing plate under it?" Yes
"Don't know if there's foam in the way." There is, just cut through it. You will probably cut through a piece of wood that is part of the backer plate as well.
"And is there already something under the bar that I will have to remove, like an old backing plate?" Yes, probably a rotted piece of wood held in by a strip of fiberglass.

deck plate backer.JPG


Here's a link to our blog on rudder conversions, some of the same steps you'll take to access the backer block. Small Boat Restoration: Search results for conversion
 
More things to consider:

1) A member here suggests cutting access holes in the bottom of the hull. The repair is more "involved", but basically invisible.
2) The later style of rudder can be purchased with plastic "cheeks"—rather than the more-preferable older aluminum.
3) Items listed at eBay can be bought for a bid—rather than the higher "list" (Buy-It-Now") prices.
4) Your old rudder parts have value at eBay, but understand how the bid process works. Don't "lose" your rudder for a 99¢ bid!
5) A new stainless steel gudgeon plate should cost less than $15.
6) With a new inspection port, replace screws with (the more secure) stainless steel bolts.
7) Replacement backing plates can be made of different species of hardwoods—or use aluminum or stainless steel scraps. Below is a grille for cooking BBQ shrimp. Suitable in size for several permanent stainless steel backing plates, it was purchased at a yard sale for $1.

P5220032-002.JPG
 

At this point, I'm not really interested in changing rudders, I just want a small boat I can get on the water with. This would be a lot of expense for a boat I haven't even sailed yet.
Why do you have pictures of a yellow boat with the hole near the transom, and a blue boat with the hole where I was going to put it, and a white boat as well?
It seems like I can't fix mine with the thought of redoing it later, because the hole needs to be near the transom. Or have an extra hole in the deck...
Can you reuse the original rudder, or do you need to replace that too?
 
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As I recall you can get the new rudder plate in in the future even if the hole is a little ways away. It has to be within arms length. It’s trickier but doable

You will very likely hit foam regardless of where the Bible says there is foam. They liberally used yellow spray in foam and I think the white blocks gets a bit closer to the stern than shown.
 
Well, since I'm cutting the hole anyway, I would prefer using the new hardware if I didn't have to buy a new rudder, but I can't tell if he used his old one.
 
You would have to recut the upper part of the old rudder to fit the new rudder
cheek. I think after doing that you'd realize it would have been just as easy to
start from scratch with a new wood blank. You can get a mahogany board
from a big box store for about $18. Buying a new rudder seems way to expensive
too me.

Small Boat Restoration: Sunfish Rudder Conversion
 
Oh, if it can be done with a little chiseling, that would be much easier than building a whole new one. Stick some cardboard in the cheek, trace around it, transfer that and the rotation curve to the rudder and shave off the difference...
 
You’ll need the new straps. I have seen the straps bent in order to fit the old tiller, but that’s not a common modification. You could buy the new straps and use an old hockey stick for the tiller.
 

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