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.

Spars, Mast Hinge, Part 9: Cutting the Mast

The base of the mast, just after the cut
Having installed the new G-10 mast step and the appropriate hinge components on Oystercatcher, my Ericson 25, I now needed to cut the base of the mast. This subtraction, so to speak, from the base of the mast would account for the height I had added to the deck of the boat through the installation of the G-10 and the hinge components.
To make the cut, I began by setting up a temporary cutting table in the yard.
Before setting the miter saw on the table, I made sure that it was level in all directions.
I then double-checked my earlier measurements.
An important factor that I had had to consider all along was the location of the cutout for the centerboard line.
I needed to cut off enough of the mast to remove entirely this original, centerboard line cutout. Otherwise, it seemed to me, the base of the mast would be structurally compromised.
Fortunately, according the calculations I had made before I ever ordered the G-10 for the new mast step, if I constructed a new step at least 1.5 inches in height, then I could remove 2.75 inches from the base of the mast. The top of the centerboard line cutout was at 2.75 inches, so this was one important reason why I decided to construct the new step to this 1.5 inch height. The other important reason, which I discussed in an earlier posting, was that I needed to build up the step enough to where the mast would clear the forward hatch when it was in the process of being stepped.
The silicon bead that the previous owner had applied around the centerboard line cutout was an annoyance, so I did my best to remove it before making the cut. This guy apparently thought that the silicone would help divert rainwater from entering the mast. I remember that he also had some plastic flap sloppily taped in this area.
If you click on the picture below, you'll see my pencil mark notes: "with 1/2 inch G-10," "with 1 inch G-10," and "with 1.5 inch G-10."
Another thing that I did before making the cut was to create a pattern for the new centerboard line cutout that I would need to make.

2.75 inches.
2.75 inches. I only had one chance to get it right.
Before making the cut, I decided to take a picture of these markings that would be forever removed from the mast. I've never been able to decode them.
The time had now come for me to put the miter saw on the table. Again I checked for level.

I also checked to make sure that the mast itself was level. It of course was not. Notice the stack of scrap pieces of 2 x 4 material on the second sawhorse.

Without a doubt, I did more preparation and more thinking about this cut than any other in my entire life. My boatyard owner friend who works with aluminum on a daily basis had assured me that my approach to cutting the mast in this backyard, makeshift fashion was a sound one.
Reining in my concerns, I slowly gripped the mast with my left hand, and with one resolute motion I pushed the saw blade through the aluminum from one end to the other.
The cut was clean. All evidence of the old centerboard line cutout was gone.
I deburred the aluminum with a piece of sandpaper.

Now I prepared to create the new centerboard line cutout.
I decided that the best way to replicate the original cutout would be to use a hole saw. Therefore, I pulled out my homemade gauge and scribed a circle.
I used a center hole punch to mark it.
Then I drilled a small pilot hole.
I used this to guide me in my cutting of the hole with the hole saw. For some reason we call this thing a hole saw, even though it's more of a large drill bit.
The hole was clean in appearance, but it had a significant number of burrs.
I first used my fiberglass cutting bit on my Dremel to deburr it.
This wasn't the right attachment for the job. The small grinding wheel did better, but it was still not ideal.
Now I needed to create the lower part of the cutout. It felt awkward trying to do it with the jigsaw.
Therefore, I decided to use the drill. Again, I marked the spot with the center hole punch.

I could only drill so far before the drill bit started to walk into the large hole.
The jigsaw was now more cooperative. I used a Bosch T118B blade for this, just as I did on other projects that required me to cut aluminum.

I finished off the job with the fiberglass cutting bit in the Dremel.
The small, 50 grit sanding drum was better than anything else at deburring the aluminum.
Now that these tasks were behind me, I could focus on the installation of the top of the mast hinge to the new base of the mast. I address this part of the project in my tenth and final posting.