2016.08.05 - Rudder Stock - The Rope
Today's first task was to change the anchor point of the rope that pulls the blade down into something a little more friendly. The current rope seems to have been glued in place and whilst that has obviously done the trick, the rope has started to fray at the point where it enters the wood. If this were to break when sailing it would be impossible to replace in situ. So the old rope was removed and a new anchor point created consisting of a silicon bronze screw in the edge of the blade to which the rope will be tied. Then, if the rope breaks then a new one can be easily added simply by lifting the rudder of the pintles, tying on a new rope and putting the rudder back.
The Le Tonkinoise varnish arrived today and I was able to try it out on the table top. I flattened the top as before and put on a thin coat of the varnish. It looks good and covers well but I won't know much more until I have a few more coats on the wood. Have to wait for 24 hours before I can recoat and the recommendation is for 5 coats for marine purposes.
I also looked into the preparation of the existing paint inside the hull. I have a couple of things to add to the hull to allow slats on the inside of the lockers and then I'll be wanting to paint. However, whilst the majority of the epoxy will be easy to sand there is a fair bit of the old paint that is not accessible enough. Instead I'm going to use Owatrol ESP which is a preparation that you paint on to non-absorbent surfaces and when it has dried you then paint over the top and the paint binds to the ESP. So, the parts of the hull that can be sanded will be, then the whole inner surface will be dusted and cleaned. The ESP will be painted over everything and then, two days later I'll be able to paint the hull.
Fortunately there was a hardware shop in Dereham about 30 miles away that had the ESP so I drove over and bought a litre. So, by the time I'd done all that I needed a break. The varnish will be dry enough in three hours to be able to work in the workshop again without spoiling the finish so I'll do some more this evening.
With the rope removed you can see how it was fastened. The end of the rope was fed into the hole you can see on the left of the rudder and laid into the now exposed groove. This was then filled with putty or glue or something to hold the rope in place.
I have extended the groove beyond the extant of the original and drilled a pilot hold for the screw at the end of the new groove.
Un-thickened epoxy was then poured into the "trench" in order to fill it up and also brushed on to the newly exposed wood.
A side view showing the screw anchor point.
I had some epoxy left over and this was used to coat the inner faces of the rudder cheeks and the inside end of the spacer since this will be very hard to do once the stock is assembled.
Here is another part of the rudder stock. It is a 15cm x 30cm sheet of bronze 0.9mm thick and will be used at the top of the stock. The bronze will be carefully bent around a suitable former so that it forms a U shape and this will be screwed or bolted to the top of the stock. It's purpose it to allow the tiller to be slotted into the stock.
But, I'll not do the bending until the stock has been stuck together as until then I'll not know exactly how wide the top will be.
Here is an example of what I mean. I could have used steel as that would have been much cheaper but steel rusts a lot and bending it is not easy. Stainless steel doesn't rust (much) but is more expensive than steel and harder to bend. So bronze it was.
There are rudder stock heads available to buy for Wayfarer dinghies but these cost nearly £70 each and that is more expensive than I paid for the bronze!
This is how the three pulley wheels, or sheaves, will work. The red lines represent the strings. There is a slot at the top of the rudder in which the ropes will move as there will be along the forward edge of the stock. The the first task is to cut these slots. The sheaves that will be used are the same diameter as the aluminium ones shown here but they are 11mm wide. So I need a slot 12 mm wide.
So here is the 12mm wide slot cut in the spacer. Looks good. Can you see the mistake? Yes, I cut it on the wrong edge. That's the trailing edge and it should be cut in the leading edge. The slots didn't really work so I just cut the entire spacer and I'll add pads where I need to.
The spacer with the bits cut out for the sheaves. I left the slot in the top of the spacer as that wasn't too bad.
Here I have put the spacer on a cheek piece and you can now see that the spacer is narrower than the spacer. When the top cheek is put in place there will be a slot in the correct place. Quite a wide slot but that will be fine.
Another shot of the same thing but showing the entire length of the spacer.
And the wrong slot? I had plenty of Sapele offcuts so I found some that fitted and glued them in. But it was quite annoying so I stopped for the day.
Note to self: It's fine to measure twice and cut once provided that when you cut you follow the line you measured.