Spongy Rudder Resolution 2.0

This is my solution to the spongy rudder problem Shan Skailyn experienced during our voyage in March. If you remember, the rotating plate to which the rudder hinges attach, the plate that makes it a 'kick up' rudder, had problems. Originally it was made out of plywood (see picture). After about 4 days of sailing the plate became soft for some reason and was twisting and flexing so much that the rudder lost much of it's effectiveness. We also feared that the thing might actually tear off if we didn't somehow fix it. We managed with the unbelievable provision of a handful of large washers. This fixed it temporarily, allowing us to finish the voyage... but just barely. By the time we arrived at our destination up north from Madang the thing was acting up again.

I asked some folks on the woodenboat forum, on the "outrigger and proa thread" what might be done to avoid this problem. Someone suggested (Gary Dierking perhaps?) plywood sandwiched between two aluminum plates. He also suggested plywood made of a stiffer type of wood. Can't remember what type it was and I don't have access to the internet at the moment to check. My solution varies only because I am limited on resources. I had to make do with what I currently have on hand. I only had enough aluminum left over to plate the one side. I think it should work though.

This is an 1/8" thick aluminum plate fastened with 13 epoxy bonded wood screws into a plywood base. As well as being attached with screws, for what it's worth, the aluminum plate is also glued with epoxy to the wood. Not sure how strong the bond will be to the aluminum, but at the very least it provides waterproofing for the wood between the plate and the plywood. Then all the rest of the wood was coated with epoxy resin, allowed to soak in and reapplied again while still uncured, so as to soak up as much of the stuff as possible. This should hopefully make the wood much less penetrable by water. The whole thing feels pretty strong. All the rest of the boat is out in town so I have to wait till we go out again in September to get it all assembled.

For comparison, I've attached here pictures of the original assembly (with the rudder attached) as well as a picture of the new one I've constructed.

Shan's Tiller

Having just come back in to the bush from being in town for a while, I didn't have a lot of time this weekend for anything but laundry, laundry, and more laundry... oh yeah, and unpacking boxes and boxes of food and trying to organize it all. Imagine only getting a grocery run every 2-4 months.

But I did manage to get some little bits here and there, during which I managed to glue up one more paddle blade, and even better, construct the tiller for Shan Skailyn's rudder. I was concerned about using a bolt at the pivot point (at the base of the tiller) for fear that the thing might work itself loose. Since I still have some leftover brass rod, and some loose stainless steel washers and retaining pins, I decided to rig something up with that. My only concern with the retaining clips is that they're yet another little pointy, grabby thing that a rope is bound to snag. We'll deal with than when it becomes necessary.

For the paddle blade, I'm not sure what kind of wood I'm using. It's the same stuff that the Mibu folks use for making siding for their huts. It's very very lightweight, long grained wood. Hope it's strong enough for a paddle blade.

Finished leeboard and rudder

Here's the pix of the finished leeboard and rudder. Not a whole lot else to say. I would like an opinion on my rudder hinge (whatever that thing is called). Is the way I have it set up going to be alright with the forces that it will encounter? I'm just a touch concerned that the little 'tongues' that are holding the pin just may want to tear.
Bob from Arkansas, any thoughts on that?

Just Plane Fun

Planing, planing, and more planing. That's pretty much all I've done during the little bits of time I spent working on Shan Skailyn this weekend. Well, that and shaping with a rasp and belt sander. Oh yeah, and I worked a bit more on the rudder hardware.
Since the hull is on standby until I get more of my ring shank nails, I'm working on the many other small things that will undoubtedly encompass many of the required hours to get Shan Skailyn ready to sail.
What I was planing so much was the leeboard and the rudder. They've been completed shaped at this point and I'm quite happy with how they turned out. It was surprisingly difficult to give them the right shape. I drew out the profile first and cut it out of a template so that I could lay it over the curved face to compare with and shave off where needed. Finished things out with the rasp and belt sander. Pretty much all that's needed now is a good once over with some 120 grit and they'll be ready to have 5 or so coats of polyurethane. In case anyone is curious about the weight of the leeboard (remember my concern in the last post?) it's down to just 5.8 kgs (12.8 lbs). Still kind of heavy in my estimation, but I think we're going to leave it. If, when Shan Skailyn is completed, it seems some weight needs to be dropped, then I'll just have to make a new one someday.
The rudder hardware is coming along nicely. I'm getting my stainless from an old washing machine tub. It's been rather hard to cut! I've also had difficulty bending the pieces exactly as I want too. So far I've got one piece completed, another one partially bent and two others to shape up a bit more before bending to their final shape. Bolt holes will come later. I figured it would be difficult to bend everything with precision, so it didn't make much sense to try to drill those first and go through the heartache of not having them line up later. Glad I made that decision. It would have happened just as I suspected.
Oh yeah, one sad piece of info to add... I broke my only bandsaw blade. Yes, let the tears flow. Will have to work on getting a new one here somehow in the coming months.

Beginnings of leeboard and rudder

I didn't get a whole lot of time this weekend to work on Shan Skailyn. I'm out of 3/4" ring nails at this point. So I'm waiting for more of those so I can start assembling the hull which sits, just about ready for that next step.
Instead I started working on some of the other parts. I cut and laminated the timber for both the rudder and the leeboard. Got both of those planed down to thickness, and even managed to cut out the blank for the leeboard. Regarding the leeboard, I'm a bit concerned about the weight. I imagine that it undergoes a fair bit of stress, so I used a fairly strong wood that also ends up being a bit heavy. Actually, when I laminated it, I alternated between the heavier wood and a lighter wood in an attempt to cut down on the weight. Anyway, what I've ended up with after I've planed it down to thickness, cut out the blank, and not having yet shaped it, is a leeboard that weighs just over 7 kgs (about 15.5 lbs). Isn't that weight a bit excessive for a leeboard? Seems heavy to me. I would guess about 3-5 more pounds will be taken off once it is all shaped. Based on knowledgeable feedback, I may just have to re-make it with lighter timber.
I also began cutting up my sheet of stainless steel into pieces to use for the rudder hardware. That is some hard stuff to cut! I broke my last sawzall blade for cutting metal. So then I switched to my skil saw with a metal blade. I did manage to barely finish cutting my pieces before the last of the blade was worn down. Hopefully I can manage to avoid any major mistakes with these. I have nothing left to cut new pieces with! It's tin snips and grinders and files from here on out. Once I finish cutting these, I'll have to find a way to bend them all with a fair bit of precision so that all the holes for the through bolts (for securing to both the rudder and kick up assembly) as well as the holes for the hinge pin match up. If I end up not finding a way to bend them that precisely, then the other option would be to bend them before drilling the holes, then put a scrap piece of lumber between the bent 'flaps' and then drill through all of it at the same time.