Ericson 25, Oystercatcher: Spars, Mast Hinge, Part 6: Drilling Mounting Holes in Mast Hinge and G-10 Step

Spars, Mast Hinge, Part 6: Drilling Mounting Holes in Mast Hinge and G-10 Step

Using the original, aluminum mast step as a guide for drilling the mounting holes in the mast hinge plate

Having tapped the holes for mounting the bottom plate of the mast hinge to the G-10 mast step, it was now time to drill mounting holes in the top plate of the mast hinge for mounting the original, aluminum mast step to it. Likewise, it was now time to drill mounting holes in the new G-10 mast step for mounting it to the old mast base/step.

The old mast base/step with the original, aluminum mast step mounted to it.

Again I called upon my friend with his machine shop tools and machine shop expertise to carry out these tasks. First, he clamped the original, aluminum mast step to the top plate of the Dwyer brand mast hinge.

Then he used the drill press to drill four, 1/4 inch holes through the stainless steel plate. The original holes in the aluminum mast step served as guides. The liquid that you see is a lubricant that aides the drill bit in its cutting through the metal.

After my friend had drilled all of the holes, he grabbed the socket wrench, and he temporarily installed the 1/4 inch stainless steel hex bolts that would join the original, aluminum mast step to the stainless steel plate of the hinge. These simple tasks were enough for one evening.

The next morning, back at my house, I worked to solve a problem that had presented itself several days beforehand. You'll recall that I had originally planned to use a piece of oak for the anti-compression block. Then I decided to use G-10. It was a more durable material, one that would surely resist compression more readily than the wood, and one that surely would not rot.

I had planed down the piece of oak to a thickness of approximately 7/8 inch. The piece of G-10 was only 3/4 of an inch. Somehow I needed to increase the thickness of the anti-compression block by about 1/8 inch. But how?

I thought about plastic, I thought about metal, and then suddenly I remembered that I had several pieces of fiberglass that were about 1/8 inch thick. These were pieces that I had removed from the boat when I had created cut-outs for stowage space behind the backs of the settees in the main salon.

This fiberglass still had wax on it from the mold in the Ericson factory from 1975. I removed the wax with xylene, a hearty solvent known for its ability to cut through wax.

After I had cleaned the piece of fiberglass, I broke out the quarter-sheet sander and attached a piece of 40 grit paper.

From one side of the fiberglass I removed all of the gel coat. I'll tell you right now that Ericson didn't fool around when they applied gel coat to their molds. It took some vigorous sanding with this 40 grit paper to remove all of it.

Why did I remove the gel coat only from one side? Because I wanted to create shims of two slightly different thicknesses.

I used the abandoned, oak, anti-compression piece as a guide for cutting the pieces to size.

I was glad that I had taken the time to make two different pieces.

The un-sanded one fit just right.

Yes, it fit just right . . at this moment.

At this point, however, I had not yet taken into consideration the amount by which the sealant might change the measurements. When the time would come for me to mount all of this into place with sealant, the measurements would indeed change, and the thinner, sanded piece of fiberglass would be the one that would fit just right. But I'm getting ahead of myself.

There were still a few things left to do. I needed to drill holes in these fiberglass shims.

Now both were ready to go.

I went ahead and sanded the block at this time. Eventually I would paint it. This would aid in the adhesion of the paint.

Now I could mark the anti-compression block in preparation for drilling it with the forstner bit.

The forstner bit holes in the anti-compression block were necessary to allow room for the hex heads of the 1/4 inch bolts that would join the original, aluminum mast step to the top plate of the mast hinge.

As I was doing all of this, I continually referred to the wooden mock-up step as a guide.

Back at my friend's shop we put the anti-compression block in the vice and the forstner bit in the drill press and got to work.

After this, we could bolt the old, aluminum mast step to the top plate of the new mast hinge. Likewise, we could join this top part of the hinge to the bottom part of the hinge. With everything together and lined up, we could drill the 1/2 hole for the centerboard line.

Using the existing 1/2 inch hole in the original, aluminum mast step as a guide, my friend drilled a 1/2 inch hole through the first steel plate, the G-10 anti-compression block, the bottom steel plate, and then the steel halyard organizer plate.

He did not try to go all the way through the G-10 mast step at this time. He only went far enough to dimple the surface.

I loved watching this machine in action, so I took a few extra pictures.

It's a relic of days gone by, but it's still as robust as it ever was, and probably more robust than many new drill presses on the market today.

After my friend had drilled the 1/2 inch hole, he drilled the 1/4 inch hole for the bolt that would secure the new mast step to the old mast base/step. This is the 1/4 bolt that would pass into the mast compression post. The stainless steel nut/loop on its end would be the terminus for the centerboard line inside of the post.

In the midst of drilling this 1/4 inch hole the drill bit broke.

At first my friend tried to remove it with a vice-grip. This didn't work.

Then he removed all the hardware from the G-10 mast step.

With this additional working room he was able, at last, to extract it.

He then put the G-10 mast step back into the drill press and tried again with another drill bit. This one also broke.

To get this drill bit fragment out of the the G-10 he resorted to putting the G-10 in his large bench vice.

He then gave the G-10 one or two solid whacks with his wooden mallet.

I just had to take a picture of this mallet. His grandfather had crafted this mallet out of the wood of a live oak tree. This type of wood, with its tight, twisted grain was a favorite of shipbuilders long ago. It was used on the Constitution in the 18th Century, and it's still used today on wooden tall ships, such as the Spirit of South Carolina.

With its dense swirls, this is an incredibly tough wood. It's next to impossible to split it with an axe, and it even gives a pneumatic splitter a hard time.

While I was at it, I also took a picture of one of the nearby drill bit racks. My friend reported that some of these his grandfather had machined by hand.