Rudder blade help.

Quinn McCarthy · Post by **Quinn McCarthy** » Tue May 27, 2008 9:01 am

Over the winter I built a new rudder assembly with new parts from Stef and a tiller handle I made and a new blade from Phil's foils which isn't done yet so we are using the old one. Our old assembly had 2 bolt one which is the regular pivot bolt and a second one about 6" down and 6" back which we used to keep the blade from kicking back. On the new one we only have the 1 pivot hole and the blade tends to work it's way back a bit. I am wondering how much torque I can put on that bolt to keep the blade from coming back? I really don't want to drill another pin hole like my old one in my new cheeck plates. It seems like eveyone is getting by on one.

Thanks.

Quinn

Marionete · Post by **Marionete** » Tue May 27, 2008 10:54 am

What material did you use to make the new cheek plates? Was it stock 1/4 inch aluminum plate; did you paint it or was is anodized?

I need to replace those on Hull 23 since the pivot bolt hole is badly corroded and elongated.

Quinn McCarthy · Post by **Quinn McCarthy** » Tue May 27, 2008 11:12 am

Marionette,

They are 1/4" black annodized cheek plate. They are available on the class web site.

Quinn

dave · Post by **dave** » Tue May 27, 2008 3:24 pm

You may have thought of this but you can have the holes welded closed, ground fair and redrilled for less money.

Marionete · Post by **Marionete** » Tue May 27, 2008 6:43 pm

I saw a pair for sale under "boats for sale, etc" for $250 - is that the going rate for new rudder plates?

Jeff Bonvallet · Post by **Jeff Bonvallet** » Wed May 28, 2008 11:13 am

Try over drilling and filling the hole with a bronze bushing from the hardware store. I did that several years ago and only have to replace the bushings every 2 or 3 years, only a couple of bucks for both. They are a little long, but easy to sand down to the proper depth. The bronze does not seem to react with the aluminum and it is soft, so it acts as a sacrificial metal aganist the rudder bolt.

dave · Post by **dave** » Wed May 28, 2008 1:28 pm

Great tip Jeff. I used to do the same thing on some of my catamaran rudder gudgeons.

Quinn McCarthy · Post by **Quinn McCarthy** » Wed May 28, 2008 1:49 pm

Ya great tip Jeff.

How is that going to hold the rudder blade down better?

Quinn

dave · Post by **dave** » Wed May 28, 2008 3:27 pm

Quinn, torquing the bejesus out of the rudder pivot bolt IS NOT the answer to keeping the blade in the proper location. You are still going to have to put a keeper bolt through AFTER making sure that the rudder blade/cheek plates are mounted on the boat and the trailing edge is lined up perfectly verticle, with that of the keel. Anything else is pure guess work.

Post by **Tom Elsen** » Wed May 28, 2008 4:13 pm

Hi Quinn

Make sure that the rudder head hasn't deformed a bit, such that you aren't getting good contact between the aluminum cheeks and the rudder head.
Then, make sure that the pivot bolt has as wide a head as you can find. Use as large OD bolt as you can find too. Add large-diameter, thick washers on both sides.

If you're still having some problems, you can try the old trick of using a cut coffee can lid as a 'washer / jammer' on the inside, between the rudder head and the box cheeks.

Finally there's the "Mootz Shim". Get a bunch of wood shims and jam one between the preventer pin and the aft / top of the rudder head. Works like a charm...at the rate of one shim per day.

Quinn McCarthy · Post by **Quinn McCarthy** » Wed May 28, 2008 5:00 pm

Thanks Tom

I will give that a try.

Quinn

Stef · Post by **Stef** » Wed May 28, 2008 9:10 pm

Quinn, there is a hole 5/16" dia for a brass pin! Some guys use a wooden dowel or even a BIC pen. The other holes along the edge are 1/4" dia for bolts that go through the wood that keeps the plates apart the correct distance.
DONT weld or drill anything, you will remove the anodize. All the holes you need are in the plates.
If you need more info call me, 570-226-6020.

Marionete · Post by **Marionete** » Thu May 29, 2008 8:31 am

It would appear that the corrosion on the aluminum plates will require bushings of at least 1 inch diameter with a 1/2 inch pivot bolt hole. Are these (bronze) bushings easy to find?

Second question: there is additional corrosion on the plate where the lower strap attaches - it appears that some additional scaling has made the plate thinner from corroded material. Other posts here talk about anodized aluminum, but my plates are painted so it appears that they may have been replaced with straight aluminum or are just badly maintained.

Quinn McCarthy · Post by **Quinn McCarthy** » Thu May 29, 2008 8:58 am

Thanks Stef

I will look for that 5/16th hole tonight.

Quinn

dave · Post by **dave** » Thu May 29, 2008 9:08 am

Stef, if corrosion is the problem, worrying about the anodizing is a moot point!

I use to deal with putting the wedge in under the keep down pin too. The main problem is that you have no idea of where that puts the blade rake fore and aft and it's not precisely repeatable. The boat ABSOLUTELY sails the best with the trailing edge of the blade hanging vertical, and by that I mean 90 degrees to the waterline. Guessing at it is just that.

S2 7.9 Meter Class Association

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