[Public-List] Rudder Repairs (yes, another thread, possibly another ruder variation)

[laserandy at aol.com]

Rachel,

After looking at it some more last evening and looking at some photos another lister sent me this morning, I have come to the conclusion that our rudder is exactly the way it's supposed to be, only question is what to use to re-fill the places over the straps where I chipped out some old filler, and what to do about the wood filling the gap down the side.

J and I looked at it for a little while last evening and I think we figured out half of the logic behind the construction.? As you mentioned, the groove is cut down the rudder to permit fastening of the nuts that hold the blade to the shaft.? Our thought last night, was that in order to rectify the compromising of the rudder's integrity that the groove would cause, they fastened the brass/bronze straps across the gap to serve the purpose of a glass skin.? 

I think I figured out the other half while thinking about it this morning.? While they filled the top part of the groove, where the rudder is narrow, with fairing compound, they filled the lower part, where it's wide and subject to more stress, with the strip of Mahogany.? The Mahogany is there to take up the compression loading while the strapping takes up the tension loading.? Had they known more about fiberglass, they probably would have filled the void with foam, feathered back the sides, and glassed over the groove, obviating the need for the straps and the mahogany . . . . but they didn't.

Based on this, I'm reluctant to remove the mahogany and fill it with something that I have no way of guaranteeing will be devoid of gaps below the surface and which may (likely) will not have the same sort of compression resistance as the mahogany.? The wood in our rudder is rock solid, I could barely dent it with a chisel last night.? 

This comes full circle to the questions of what to use to fair the various spots.? There are three distinct fairing jobs to do, the principal one is over the mahogany strip.? Anything too stiff is going to crack, anything too spongy is probably going to let in water.? The second one is over the straps, this is fairly straightforward, thickened epoxy should do the trick.? The last one is around the shaft.? Another lister sent me photos of his rudder (which is the same as these two), the shaft is exposed with no fairing, part of me says just get all the old fairing out and let them paint it, part of me says fillet the sides of the shaft with thickened epoxy, if it falls off it falls off, no big deal.

So, back to the hard one, what would you cover the mahogany with?? It is just a fraction below the surface of the surrounding skin, not enough of a void to readily fill with anything other than a thick coating of paint.? I could paint it with epoxy, fair over the painted epoxy with thickened epoxy and sand it, although I think we all know that will eventually crack off.? I could re-fair it with Bondo, which will grip the wood, take the paint, but let water in to the mahogany, and that's pretty much where I am in my decision making process at the moment.? 

Any other thoughts on what would make a good elastic waterproof filler?? Is mahogany sufficiently rot resistant that fairing it without worrying about water intrusion is sufficient?? Per Rachel, I believe there's gelcoat behind the wood, so the worst case would be to replace the wood when and if it eventually rots.

Anyway, one way or another the job will be finished by Sunday night, they're painting the bottom Monday and launching early next week.? 

Rachel, please don't stop posting, being able to work through these sorts of problems with a lot of contrasting viewpoints and experiences makes it possible to own these boats without spending a fortune (this 'repair' was going to cost a fortune for the yard to do).

Andrew

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