rudder repair advice needed

Discussion in 'Sunfish Talk' started by MartyChafkin, May 8, 2004.

  1. MartyChafkin

    MartyChafkin New Member

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    I have a mid-70s sunfish that has the new style blades, which are in need of refinishing. When I took the rudder hardware off, I discovered that the rudder had two short splits hidden under the cheeks. Since I don't want to buy a new blade for $130, I was wondering about the feasibility of a repair.
    I thought that I could run the top edge over the blade in the table saw to make a deep kerf and then epoxy a spline into it. Has anyone done this? Am I nuts? Would aluminum work better than wood, as a spline?
    Is there any other source for a cheaper blade than the dealer? Doug and Dutcher, are you guys still out there?

    Thanks, all, for any help,
    Marty
     
  2. supercub

    supercub Member

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    Marty, Suggest you get a copy of the Sunfish Bible. Page 344 in the SFB talks about the problems you have and more.The SFB basicaly drills 1/4" holes in the leading or trailing edge, deep enough to go through the crack (about 4") and then epoxy in a brass or steel rod in the hole. The rod from the trailing edge is about 1-1/8" above the rear pivot hole. The front rod is about 1/2" above the top front rudder hole, with a second rod (about 2"-3") about 1/2" below the top front rudder hole. What you suggest is ok (IMHO), just make sure you have a good fit with the spline in the saw cut. It may seem obvious, but make your wood working repairs before drilling the holes. After inserting the rods, the SFB suggests filling the holes with grey Marine-Tex. You could also glue in matching wood plugs and contuor them to shape. Finally, you can fiberglass the whole rudder, just remember to keep within the demensions as shown in the ISCA rules on the SF Class Home page. Good luck on your repairs.
     
  3. supercub

    supercub Member

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    Marty, just re-read your post. Unless you have a jig to hold your blade perfectly vertical (such as panel jig) on your table saw, don't try it. It is too dangerous due to the length of the board to attempt free hand. Lay your board flat on the table and make your cuts through the cracks, in effect making them a little wider and a little bit longer. Then epoxy your spline (slpices) in place and sand smooth. Then add the rods and/or fiberglass if you want. Again, good luck.
     
  4. WIUPgamer

    WIUPgamer New Member

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    Don't use a regular steel rod such as 1040. The SF Bible says to use Brass or Stainless Steel. Less chance for corrosion problems.
     
  5. Neil

    Neil Member

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    Marty. I’ve repaired furniture and stringed instruments for a living for the past 12 years, so this is something I am very familiar with. Your idea of a spline is a good one if you have the skill to make the cuts on your table saw. However, it may be overkill. If the cracks are small and they don’t affect the overall strength of the rudder, you may be able to stabilize the cracks by using water thin superglue. Use a professional woodworking type like Satellite City or Rockler Woodworking’s brand. The water thin glue will wick into the crack by capillary action. Work on one crack at a time. Apply the superglue until the crack won’t take any more glue and then catalyze the glue with accelerator. I have found that repairs of small cracks made this way are as strong as the original wood. If the cracks need reinforcement you can spline them. I've used wood splines, but I’ve also developed the use of form fitting fiberglass splines made from fiberglass cloth and epoxy resin. Precut your fiberglass cloth the length and twice the size of the depth of your saw cuts. Then mix your resin and coat the saw cuts (don’t fill). Then saturate each piece of fiberglass cloth with resin and stuff it into the cuts by folding and pushing it in the center. Continue doing this until the cuts are filled. Once the epoxy cures, you can trim the excess fiberglass with woodworking tools. This makes a very solid and waterproof repair. Good luck with your repair.
     
  6. MartyChafkin

    MartyChafkin New Member

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    Very nice advice, indeed. Thank you everyone.
    I do have a copy of the Bible on order and will review your advice when it arrives. The fiberglass method seems very interesting as the cracks run to the top edge and have opened up a bit. That, I suspect is the result of water swelling the fibers. Cutting a kerf that removes some of the damaged wood seems like a good idea to me.
    You're quite right about the danger of table saws. I sometimes miss the obvious when I am desparate. I have all the West System epoxy and catalyst, etc.(105/207), to coat the rudder, which was the original goal of this project. Perhaps that will work to stabilize the fibers and secure the glass cloth. Like most cans of worms, this one has gotten a bit more involved now that the top is off.
    Thanks again!

    Marty
     
  7. MartyChafkin

    MartyChafkin New Member

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    A little more information, in light of your very knowledgeable responses:
    While some of the cracks are small, there is one that runs from the top edge of the rudder to the hole for the spring pin. That one concerns me as it seems like that corner of the rudder could break off. Bad, I should think.
    There appears to be a pin in the rudder already, running from the trailing edge, above the tiller hole, to just above the cheek pivot hole. (I apologize for the non-standard terms.) It was not drilled perfectly and has split out the wood slightly on one side, just above the cheek pivot hole. The wood there is blackened and splintered. It is not so bad that I can see the pin, but water is obviously getting in there.
    Would it make more sense to buy a piece of Honduras Mahogany and make a new rudder? I feel confident in my ability to cut the rudder on the bandsaw and I can shape it with the router and sander; it is the original project of coating it in epoxy that is new to me. I know it won't be as good as a brand new one, but a piece of wood will cost about $17.00.
    Thanks again, everyone, for the benefit of your experiences.

    Marty
     
  8. mike4947

    mike4947 Member

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    Marty, the problem is you'd have the same condition in less than a season with using just wood. It really needs to be pinned to strengthen it. If the class would relent on the 120 angle rule and allow the rudder to be more vertical it would have a lot less stress on it and also have a better bite in higher winds.
    Wait for the Bible and follow the pinning plan and you'll have a rudder that'll outlast you, providing you keep off the bottom. ;)
     
  9. MartyChafkin

    MartyChafkin New Member

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    Ah, yes. I will pin the new board. Does the Bible recommend oversizing the holes to give the epoxy some room, or do we want a tight fit and then let the epoxy be absorbed by the wood? I am assuming 3-16 stainless for it's corrosion resistance; am I wrong? I don't know what the old one was pinned with, but it did not prevent splitting.
    Since I will not be racing, is there a better profile for the rudder? I really don't care for racing and I am definitely interested in a more stable rudder.
     
  10. mike4947

    mike4947 Member

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    I can't remember exactly what the bible says, but we've always just used 1/4 threaded stainless rod. Corrosion resistant and the threads make room for the expoy. As for the placement that escapes my sometimes senile mind.
    As for a better rudder mounting position the more vertical (drop the tip down) the less stress and the more effficient it will be.
     
  11. imported_Jon

    imported_Jon New Member

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    The stress that produces the crack in the rudder is in the outer part of the rudder skin. I have rebuilt several and have never had one come apart after being fixed.

    Take a belt sander and sand the top of the rudder to basically where the rudder cheek ends. Both sides. You need to sand it, so you will have room for the fiberglass and epoxy. If the split is down the rudder blade, then with a disk sander open up the crack, V it out so you can put a small strip of glass and epoxy. Both sides. Put on the glass and epoxy. When done sand the blade section flat, I smooth out the top part but it is mostly covered by the cheek.
     
  12. MartyChafkin

    MartyChafkin New Member

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    Thank you all very much. I will make a jig for the router to take down the cheeks approximately the thickness of the glass on both sides. I am guessing that I should wrap the glass all the way around the rudder and seam it on one side, just in front of the trailing edge. Or would it be better to seam it in the middle of one side? Have you had better luck working wet or dry? No, I have not ever worked with fiberglass or with epoxy. Should be interesting. Don't stand too close...
    The threaded rod idea is great. Solves both the issue of space for the epoxy and a snug fit. Nice.
    Thanks again; I'll report the results.
    Marty
     
  13. imported_Jon

    imported_Jon New Member

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    I have had the best luck with a single layer of fiberglass per side. Cut the glass bigger as you will be sanding off the extra. Put a good coat of epoxy on the wood, lay the glass over and then put more epoxy so the cloth is covered.
     
  14. mike4947

    mike4947 Member

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    Definitely do one side at a time. Trying to get both covered and either not sugging if you hang it or sticking if you lay it down is a real pain. The leading and trailering edge can be faired in after everything hardens.
     
  15. MartyChafkin

    MartyChafkin New Member

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    Oh, I think I know why they refer to boats as a hole in the water, etc. I wanted to remove the black, splintered wood that was at the end of the factory metal reinforcing pin so I worked at it carefully with a knife. As the pin was not installled squarely, it had splintered the wood at the end of it's travel. It is very rusty and has made the wood iron-sick. Very depressing. I do not know if there will be enough good wood left to make a repair worthwhile. Interestingly enough, the epoxy(?) plug was still in perfect condition, though the rust had made its way all the way to the end under the epoxy. I did try to drive the pin out, to not avail. I could carve the entire pin out and let in a piece of hardwood, but I am not sure that this will be strong enough. Bummer.
    I want to thank everyone for the extraordinary effort to help. By the way, the Sunfish Bible arrived today. Very nice. It will be some help in the fabrication of a new rudder, but it does not deal with this latest issue of the rusted pin.
     

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