Rudder and Rudder Shaft

The hull is sanded and ready for paint and varnish, but I've also worked on the rudder. It was a daunting task. I calculated the size using some formulas for much larger ships, then rounded up a little, then made the actual size a little smaller. It looks rather large for such a small boat, but at the low speeds Unicorn will be moving at a larger rudder will give more control.

The remaining part of the oak board from Home Depot, that I used for the breast hook, was almost exactly the right size. The fact that it is a nearly perfect quarter sawn board would make it well suited for the forces on a rudder -if it was laminated between 2 thin boards with the grain going at right angles to the grain of the main board. This makes it into a 3 layer plywood-like board.

Glue Layup of the Rudder. Note the cobbled-together long reach clamp coming down from the top.

The central stripes are the cross grain of the 3/4" quarter sawn oak board.

The grain going left-right is a 1/4" board glued on. There's another 1/4" board on the other side.

After the glue setup, the planing started. This was the step that I thought would take forever, but it was so satisfying to plane the straight grained oak it didn't seem to take long at all. The total time spent planing was probably an hour or so.

The plane I used is actually an antique. It was my father's and I think he got it from his uncle. The curved handle of the plane is broken at the top and is a little uncomfortable, but no blisters. Nothing like a sharp blade on a hand plane. The final shape is surprisingly elegant.

Drilling the hole in the rudder for the rudder shaft did not go well. The overall width of the rudder is 1 1/4" (31.8mm). The rudder shaft is 1.05" (26.7mm). The closest drill size I could get (without spending a lot) is 1 1/8" (28.6mm), leaving only about 1.5mm on each side of the hole. So the hole had to be EXACTLY straight to stay within the rudder walls.

It wasn't.  😕  This is majorly unfortunate because it not only looks bad bad it is also weaker. I added a layer of fiberglass over the blowout to help reinforce it. This problem may have been avoided if I'd purchased a more expensive type of drill bit and used a drill press, but...   I may try to do something cosmetically to cover up the blow out, but that's TBD. Perhaps my sister-in-law has some ideas. Cleverly shaped small paint patch? Ideas?

     

     

The fun part of dealing with this little goof was filling in the space around the rudder shaft with epoxy. If you look closely in the left picture above you can see a little gap between the stainless steel shaft and the rudder on the left side of the shaft. That's where I poured the epoxy in. I held a little cup of epoxy against the shaft about 25mm above the wood and let it dribble down the shaft and into that little hole, one or two drops at a time.

I dribbled. And dribbled. And dribbled. Where was it all going? Eventually I used up the batch I had made and decided to let it "go off". When I checked the next morning, a little had run out thru the fiberglass over the blow out, but it looked like it had in fact filled up the gap quite well. I may try to dribble a little more into that little hole.

No way to know if this assembly is strong enough other than try it out when the time comes!