Rudder question

I am refurbishing a 1988 Hunter 26.5. It has a wing keel and draws 3'6". I have removed the rudder (Foss foam). It appears to be a naca four series, with the sides being relatively symmetrical with several flat spots on each. Using a large contour gauge across the face of the side with the best "foil" shape and then moving it to the other side reveals several high and low spots. I am primarily a recreational sailor, racing only a few times a year at the inland lake nearby, but would still like for the boat to reach its designed performance level. Is it worth trying to get a true symmetrical shape or should I just fair it smooth and let it go? Also, the trailing edge varies somewhat in thickness, but is squared off.

 

The skin on those rudders in not too thick, so there isn't much grinding you can do without getting into the foam. You could spray or trowel fairing compound and fair it.

 

Welcome to the forum.

Fill in any obvious low spots and fair, but don't make a career out of it, just clean 'er up and have fun. Clean up the trailing edge, so it's crisp (square edges), sharp and uniform. The difference in performance level between the two versions of this rudder will not be noticeable, though measurable improvements in 10th's of a knot could be recorded, the same would be true of a more attentive skipper.

 

Thanks guys. That's about what I planned to do. Most opinions I've received were along the lines of making sure everything else is good before worrying too much about a few millimeters of rudder surface. Thanks again.

 

the only effect that having the rudder not symmetrical will do is it means you have to hold the tiller at a slightly different angle for exactly the same tack angle. It is hardly detectable, so make it smooth as advised above, but I would not worry about symmetry. symmetry on a sailboat is overrated, unless you are going straight down wind, the hull is never symmetrical in the water anyway. I think too many sailboat builders get obsessed with symmetry.

 

Symmetry is an important consideration with class racers, where the guys with clean, symmetrical appendages do better, against the those that have something less, but other wise, it's not worth much, especially if you ask your back and elbows after a day of anal fairing.

 

Mmmmm, well I am somewhat averse to 'humming' rudders and boards.....
Mostly down to assymetry, quickest test is a length of line from front to back at a given height, each side - same length? . TBH you only need to be close to prevent it, no need to get too anal unless at a reasonably competitive level.