Wood versus Fiberglass Rudder

[macjacob]

I've purchased a good used Sunfish and am getting it ready for racing this year, including the US Masters Nationals in Milwaukee. My boat has a wood rudder, wood tiler, and aluminum rudder cheeks. I'd like perspective on which parts I should keep or replace and whether I should refinish the wood rudder or just buy a new glass one.

My wood rudder is smaller than the maximum approved class dimensions. Is a larger rudder an advantage or is there perhaps an advantage to the smaller wood one if properly shaped? If I refinish it, I'd like suggestions, but my plan would be to sand to bare wood, round the leading edge and sharpen the trailing edge, apply a coat of penetrating epoxy, and then as many coats as needed of regular epoxy. Sand smooth with long battens, then paint with white Krylon so I can see weeds. I might add fiberglass to the leading and trailing edges for durability.

Is there any advantage or disadvantage to keeping the old aluminum rudder cheeks? Will they work with a new glass rudder?

Should I replace the wood tiller with aluminum or refinish the wood one?

I'm new to the Sunfish class but have raced Lasers for years. Thanks for any perspective.

 

[beldar boathead]

In what dimensions is the wood rudder smaller? The glass rudders typically dont have any advantage vs the wood. Your proposed work on the rudder is spot on. Be sure not to modify the profile of the leading and trailing edges more than the rules permit.

The aluminum cheeks are much more durable than plastic - you are luck to have them.

The aluminum tillers, either the two-tube “wishbone” and the single tube style are stiffer than the wood. The Sunfish manufacturer, for reasons known only to themselves, keeps spare parts in short supply, so hopefully you can find a class-legal one.

 

[macjacob]

In what dimensions is the wood rudder smaller? The glass rudders typically dont have any advantage vs the wood. Your proposed work on the rudder is spot on. Be sure not to modify the profile of the leading and trailing edges more than the rules permit.

The aluminum cheeks are much more durable than plastic - you are luck to have them.

The aluminum tillers, either the two-tube “wishbone” and the single tube style are stiffer than the wood. The Sunfish manufacturer, for reasons known only to themselves, keeps spare parts in short supply, so hopefully you can find a class-legal one.

Compared to the measurement diagram, the wood rudder is about 3/4 inch shorter on the maximum length from the pivot hole to the tip, and about 1/2 narrower all around. My wife's boat has a fiberglass class legal rudder, and it measures very close to the max on all dimensions. The smaller foil would generate less lift, but also less drag, so it's hard to tell where the balance would come out. Are people using the wood rudder successfully?

Thanks for the comment on the aluminum rudderhead, I'll keep it.

 

[chris williams]

Compared to the measurement diagram, the wood rudder is about 3/4 inch shorter on the maximum length from the pivot hole to the tip, and about 1/2 narrower all around. My wife's boat has a fiberglass class legal rudder, and it measures very close to the max on all dimensions. The smaller foil would generate less lift, but also less drag, so it's hard to tell where the balance would come out. Are people using the wood rudder successfully?

Thanks for the comment on the aluminum rudderhead, I'll keep it.

Well, there aren’t as many wood rudders out there as there used to be since new boats have come with the glass blades for quite a while now. That said, they were all intended to be made to the same spec. I have someone else’s wood rudder in my garage. I’ll try to remember to measure it and see what it comes out to. You could post the question on the US SFclass Facebook page. The class measurer is on there fairly frequently and he measures a lot of blades so he could probably tell you if wood ones are typically smaller. Honestly, I’ll be surprised, but who knows?

 

[chris williams]

So I just measured the wood rudder I have - it is completely unmodified from back when it was new - my guess is its an '80s era rudder. It is about 3/8" inch too narrow at the 9 3/8" station, 1/4" too narrow at the 7 5/8" station, and 1/2" too short in length. So this tickled my memory banks, and I recall that back in the day people used fiberglass, epoxy resin and microballoons to bring their daggerboards and rudders up to the max size allowed. I guess this answers why! That said, I was very competitive in the wooden-board era, so my "non-maxed-out" blades didn't seem to make a difference - I just gave the stock boards better leading edges. So, I don't have an answer for you on the wooden rudder blade. I have one that I did just what you are planning to, but I have not used it since I got a new boat with a glass rudder in 2013. To be honest, it seem unlikely that the slightly smaller rudder will make a noticeable performance difference, but I have no facts to base that on. I suppose you and your wife, or anyone else with a glass rudder, could go out to practice and try swapping the rudders and see if one of you speeds up and the other slows down. Or you could glass your wooden rudder up to the max size, or bite the bullet and pay the $$$ for a rudder blade. As mentioned by Beldar above, getting spare parts right now is not easy due to LP, the builder.

 

[macjacob]

Thanks for all the replies. To close out this post, I covered the rudder with glass cloth and epoxy. I left the cloth slightly long on the leading and trailing edges and faired with low density filler, staying within the rules for length of fairing from the edges. After wet sanding smooth I sprayed on a few coats of hard clear coat by Rustoleum. The wood tiller was covered with epoxy only and then clear coated, I decided to keep the wood look, but it is harder to see weeds. I thinned the tiller where the straps connect to the rudder so that it is the same width as the rudder and no slop. The tiller as originally supplied is thicker than the rudder, resulting in play.

The end result is a foil and tiller that’s lighter than my wife’s Laser Performance glass rudder with aluminum tiller and is only slightly smaller. It lifts up when needed and has no slop.