Spars, Mast Hinge, Part 10: Installing Top of Hinge to Base of Mast

The installation of the top of the hinge to the base of the mast
Since I had cut the end of the mast off, and since I had cut a new centerboard line hole in the side of the mast, I could now install the top of the mast hinge to the base of the mast. You'll recall that the old, aluminum mast step used to be screwed into the old mast base/step. The mast used to sit atop this aluminum mast step, held in place by gravity and by the tension of the standing rigging forcing it downward.
Now, I had bolted this old, aluminum mast step to the top plate of the mast hinge, and now I needed to mount this old, aluminum mast step in the base of the mast.
Since this old, aluminum mast step had never been mounted or screwed into the base of the mast, it needed to be tapped for holes. I decided that I would use #10 screws, which are 3/16 inch in diameter. I used a 11/64 inch bit to drill pilot holes.
Before I could drill the holes, I needed to figure out where exactly I needed to drill them.
They could not interfere with the operation of the block for the centerboard line.
They also needed to be in the center of the aluminum step so that they would grip it well.
Since the step was a little over 1 inch in height, this meant that I needed to drill the holes approximately 1/2 inch from the base of the mast.
Therefore, I marked the mast 1/2 inch from its base.
I used the center hole punch to mark the precise spot where I needed to put the drill bit.
I began by drilling the mast itself.
I then inserted the old, aluminum step and used the holes in the mast as guides for drilling the holes in the step. I started by drilling just two holes - the two that would be on this side of the mast.
After I had gotten the holes started, I removed the old mast step and drilled the first holes the rest of the way without the hindrance of the mast.

After I had finished drilling this hole, I inserted the old, aluminum step into the base of the mast and installed a screw in this hole. I wanted to get this screw into place before I completed the drilling of the second hole.
This would ensure that all the holes lined up.
This approach worked well. The second screw went right into place.
Then I flipped the mast over and marked the three holes that I would drill on that side. I would use three screws on this side, whereas I only used two on the other side. That other side received one less screw, because it was the side with the block for the centerboard line.




All of what I have just described was a dry-fit. Now I would put all of this together permanently with Tef-Gel, a product that hinders corrosion between dissimilar metals. Without it, the aluminum of the mast and the old, aluminum step would be corroded by the stainless steel hardware.
First I applied Tef-Gel to the stainless steel bolts that held the old, aluminum mast step to the mast hinge plate.

Notice the mineral spirits in the background. Without them this job would have been a complete mess. Tef-Gel is extremely sticky, and it's easy to get it all over your fingers, tools, and anything else you might touch.

Having completed the bolts, I turned my attention to the screw holes that I had just drilled.
Notice that I've not yet reinstalled the block for the centerboard line. I actually forgot about it, and I ended up having to take the old, aluminum mast step back off the mast to perform this task. That was a frustrating little job, but I'm glad I realized it before I put the mast up on the boat for trailering and launching it.


At long last this project had finally reached its end. I had constructed a new G-10 mast step, and I had installed the pieces for the mast hinge in the appropriate places for Oystercatcher, my Ericson 25. On the surface it would seem to have been a simple task, but as you have seen in the ten postings for this article, in reality it was much different. It took a lot of thought, a lot of work, and a good bit of money to get to this point. Now  I needed to make it do what it was supposed to do - raise this robust and unwieldy mast from a horizontal position to a vertical position atop the boat. That, though, is the subject of a different article.

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