making a rudder

Please see the post RE new 7.9 masts

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alanhsails
Posts: 53
Joined: Fri Nov 06, 2015 3:25 pm

making a rudder

Post by alanhsails »

Since there is no S2 7.9 One Design here, and since I plan to take my boat into the great blue Pacific, I'm making a non-kick-up rudder. As you all know, the stock rudder is enormous and incredibly thick.

Options:

1. Pay Phils Foils / Competition composites to make a new rudder. PRO: I could get some fancy semi-elliptical shapes if I wanted something different from a typical 80's style J-24/J-29 type rudder. CON: whooohooo expensive.

2. Rudder Craft... they make several rudders which would probably work. I can't get excited about a machined HDPE rudder. They flex. That leaves me with one rudder which they market for all your 24-26 foot sailboat needs, in wood core and 'glass, NACA00125 foil. It's $869. It was just a little bit smaller than I wanted and rather thinner, too, but I allow that it probably would work just fine anywhere where you didn't regularly see 25+ knots of wind and 2-3 foot chop. Upside to Rudder Craft is that they will sell you 5/8th inch rudder gudgeons with your rudder, which is pretty sweet. Rig-Rite has no such thing.

Rudder Craft also make balanced and unbalanced J-29/J-30 rudders, but they're $2100. Ooooffff.

3. make one myself.

I've now spent the $$ for a bunch of straight-grain douglas fir and have it ripped into 2-inch wide strips. The overall dimensions of the rudder will be 7 feet, 2 inches tall... submerged part will be 3' 10". Stock rudder dept is 3' 10" so this will be the same as the 1-D rudder. Chord on my rudder will be 16 inches. The chord on the G&S rudder varies from about 24 inches at the top to 13 at the bottom. My rudder will be straight-edged...basically it will be a thick BALANCED J-29 rudder. The j-24/29/30 rudders are not balanced and guys who have those boats seem to howl a lot about how the rudder loads up really badly. I want NACA 0015, which works out to a 2 inches thick blade. That's thicker than most rudders, but a lot less so than our one-design appendage. With a thick foil you get more drag, but then we're low speed things in the water, and I'd like the water flow to stay attached to the foil as long as possible during "Oh My God" moments. I'll cover it with a layer of 8 oz glass cloth in epoxy for added beef.

I suspect I will have to get custom gudgeons made, but I have a buddy who can wel do that might work out.
alanhsails
Posts: 53
Joined: Fri Nov 06, 2015 3:25 pm

Re: making a rudder

Post by alanhsails »

I've been working on two rudders. I paid $200 for a bunch of straight-grain douglas fir, for the new primary rudder, and then realized that at an empty lot down the street, there's a mess of old lumber been sitting around for a couple of years. I went and grabbed some pieces. Turns out it's nice, almost knot-free redwood. So the primary rudder has been made out of the doug fir, the emergency rudder out of the redwood.

You can follow every gory detail of the construction on either the Wooden Boat Forum;

http://forum.woodenboat.com/showthread. ... r-question

---Or the singlehanded sailing society forum

http://www.sfbaysss.org/forum/showthrea ... #post19484
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