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Wanted: Broken Rudder

summetj

New Member
Price $
50
State
FLORIDA
Anybody have a somewhat broken rudder?

I have a (fully functioning) Sunfish, but I also just received a "Boost Surfing" fin, a motorized surfboard fin. [Boost Fin: Electric Motorized Fin for any Board ]

My (perhaps wild and crazy) plan is to replace the bottom 1/2 or 1/3 of a rudder with the boost surfing fin, and see how well it will push the Sunfish (hull only) around.

I figure I'll replace my (good) rudder and use my existing cheek/tiller for testing purposes....but I need a rudder shaped board to try the idea out with. I may end up using a piece of plywood cut to shape to try things out, but I figured if somebody here had a broken rudder (preferably a break near the bottom 1/3 to 1/2, but I could possibly also repair a lengthwise split....) they would be willing to sell/ship me cheap it would be easier than making my own from scratch.

So, if you have any cheap/broken rudders you are looking to get rid of, get in touch please! I'm looking to spend less than $50 with shipping, otherwise your rudder is too nice to tear into for this (again, possibly wild and crazy) project.
 

Alan S. Glos

Well-Known Member
summetj,

Do you need a pre-1972 (old style) ot a post-19723 (new style) rudder blade?

Alan Glos
Cazenovia, NY
 

tag

my2fish
Pretty clever - could be useful for sailors that can’t raise their sail until after they paddle a ways out from shore.
 

summetj

New Member
Pretty clever - could be useful for sailors that can’t raise their sail until after they paddle a ways out from shore.
Personally, I'm mostly doing it for fun and just to test the power of the Boost Fin (I hope to use it to turn an Aquaskipper into an electric hydrofoil craft).

I considered buying a full second cheek/tiller so that I could hot swap between sails/rudder and motor skiff (on different trips) but had not really considered using both on the same trip. With a lot of work I could certainly make it closer to the stock rudder in drag, but with that propeller/shroud hanging out there it will always reduce your sailing speed just a little.

Ideally the Boost fin would regenerate and allow you to re-charge it while sailing. (But it was designed for surfboards & SUP's, not sailboats, so the designers were not thinking AT ALL of this use case....)

I've also considered a daggerboard motor...easier to swap in/out from the cockpit, but narrower space to work with....

[As a side note, I've found it much more difficult to raise/lower the Sunfish sail "on the water" than with my Banshee. I know it can be done, but it was a lot easier with my Banshee. And my lake is small enough that I never have to do it anyways.]
 

signal charlie

Well-Known Member
Staff member
Pretty cool. That extra weight of the motor flinging up probably contributed to the split. The rudder stopped but the motor tip didn't.

Any idea what the drag penalty would be when under sail? Speed is not so much my concern but rather tacking and disturbed/stalled flow over the lower part of the blade.
 

summetj

New Member
Any idea what the drag penalty would be when under sail? Speed is not so much my concern but rather tacking and disturbed/stalled flow over the lower part of the blade.
No real idea....but because the boost fin is designed for surfboards, it's relatively well optimized from a flow standpoint. I feel that the water was going around the boost fin/propeller better than the flat cedar board I was using to hold it! Underwater camera didn't show lots of turbulence anyways, but I certainly didn't subject it to ink flow analysis or a wind tunnel or anything.

Since I'm going to have fiberglass and epoxy out anyways to build doors/drawer for a bench seat I'm working on, I'm probably going to glue my board back together (it split cleanly) and then shape/sand down the flat edges and cover with a few layers of fiberglass and use some epoxy with milled fiber to help hold the boost fin plastic adapter on the end of it to make a more permanent fixture that has a bit more flow optimization. But the whole thing is a back burner project....
 
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