sharpen your blades!?!

Thread starter #1
Paige Riley's blades have the last 100mm of the Daggerboard, and 60mm of the rudder sharpened to a point.

The class rules provide for this, as long as the boards aren't reduced in size.
(rule 14 (a), (b) p35 of ILCA handbook)


Sooooooooooooooo, anyone else do this?


Perhaps ;) Rudder is easy to maintain, the daggerboard is prone to chipping.

For those not that handy with longboards and/or don't have a good eye for symmetry, give Andy P at Jibetech a call ( ) He does a really nice job tuning them up and refinishing them.


New Member
from what I know of the physics (small) and my discussions and research on the subject (somewhat larger) - There is a pretty minor improvment in performance once the width at the trailing edge gets below a certain size -

For most of us - Olympic contenders excepted - the increased performance is far outweighed by the risk of damage and the difficulty of repair. Remember - those foils are not even fiberglass, they are foam.
Thread starter #4
hmm, we'll, I got myself a new boat this week, so I'm going to try it on my new daggerboard and see what occurs.

I marked it off 98mm from the trailer edge, and am going to make a jig, and then long board up to about 270mm from the top of the blade.

Going to see what occurs..... anyone want to place bets on how it turns out?
Thread starter #5
well, just finished the first run @ 220grit. Am taking pictures along the way.

Looks decent so far, will finish up with the 220 in another half hour, then hit it with 320, then 400/600/800.

Hope to get a blunt knife edge, if that makes any sense.

It's sunny, so this is nice, and I'm not being inside doing other work, so ......FUN!
Ok I will give you that it is sanded but sharp? Most foils I have dealt with are not straight when you get them. Some sanding/heating/clamping etc is required to make them right. I am sure you are aware of this. Being "in the buisness"
I am not affraid of outside the box thinking but thats not proof. I do like her set up for the start. And her Cunningham rigging. As well her apparent upgrade of the Vang block at the boom. She is not using a clewstrap but an old school peice of spectra.

Thread starter #10
heck, I don't know if it's faster, that's why I'm trying it on my boat and see how it goes :)

You want a blunt trailing edge surely, whether sharpening it and then blunting it is fast, that's what we're trying to find out.

Doesn't sound like many people do this on a regular basis though :D
Thread starter #11
well, I just polished up the rudder, didn't sharpen the edges.

Daggerboard looks good, but the metal rods running the length came through at one point, so I'm going to have to take it down and fill/seal it up.

It isn't as pretty as paige's, I'll probably stick to my day job, but it FEELS good :)
Rob B said:
Nice shot of her rolling the boat at the start to get speed. Is that a rule 42 violation?
no. It's heeling the boat to head up right before the start, then flattening it. *technically*

I would, (now that i've heard of it) but my wooden blades are already bumped and bruised to the point that i'd lose half the weight if i tried to fix them all.
There are a few other interesting things to pick out from these pics concerning her pref for rigging - look at the same pics in row 4 (worth waiting for the larger pics to download) and see how many things you can come up with that aren't stock as far as the standard pro package goes. There's one in particular that has me thinking.
computeroman2 said:
no it shouldn't, because she's heeling to help her head up.
Just so we are all looking at the same pics:

I believe Rob's point in the first picture is that if she were only intending to head up, then the tiller would NOT be pulled over to windward as much as it is. Check what's happenening with the turbulent flow off the rudder, if anything the rudder is driving the stern to windward and the bow down, ie heading down... Next look at her forward hand - on the boom, keeping the boom out. That helps keep the boat from heading up as well.

The next picture
shows some pretty good ways to head up - ie tiller down slightly, sail being trimmed in, and a little harder to see, she is leaning back with her shoulders and using her back foot to help push the boat up.
The rule says you can heal to help steering. Race committees and other racers don't bother much to check at the start to see if you're in fact heading up or just rolling, because everyone does that at the start. She appears to have just started to lean over, so is heading the boat down so she can head up when she flattens, or maby some other reason above all of us. The point is, it's not a violation of rule 42, which was the original question.