Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Sunday, August 9, 2015

Miscellaneous Hull Work - Part 2

I continue to move forward marking off tasks that must be accomplished before fiberglassing the hull. The big elephant in the room which was completed this last Tuesday was the initial sanding of the hull exterior in an effort to provide a smooth surface for the fiberglassing. As mentioned previously, this involved applying fairing compound to the seams and screw areas as well as any other low spots, sanding with an orbital sander to knock most of the material down, and then finishing with a long board sander.

There will be plenty more of this later after the fiberglass in in place, but that's for a future blog entry.

Over the last several weeks I have been experimenting with different approaches to creating an end cap for the transom cutout. The transom is mostly plywood and in the cutout area, the end grain of the plywood is exposed. For a variety of reasons, appearance and preventing water incursion into the plywood, I wanted to apply a hardwood cap on the exposed plywood.

Since the cutout is curved in the corners, I felt that I needed to pre-bend the wood to go into this area using steam so that when it is epoxied into position, it will fit. There really is't any choice if I want to apply the end cap, it must be bent to fit.

My first approach was to make a curved form and to use the remaining 14" transom veneer material I had. However, two attempts at this proved that the wood was too thick, even after considerable steaming.

For the next attempt, I purchased a 1/8" sample of mahogany from Woodcraft. The material was somewhat less dense than the veneer material. I placed it in a a plastic tube and steamed it. Within minutes the wood began cupping. But I went ahead and bent it to see how it would work.

As you can see in the following photos, the bend occurred just fine, but the wood is severally cupped which would have made it difficult to epoxy into position and it wouldn't have looked good even if I had managed it.

A friend of mine suggested that if I formed the wood in place on the cutout, that the supporting wood might keep the wood flatter. Especially if I tried something more dense. Since I had one 1/4" veneer board left, I needed to get it planed down to 1/8" in order to try this.

Also needed would be some type of forming jig. I still had the plywood section that was cut from the transom for the cutout and I reasoned that would be usable for the job if I could figure out a way to clamp it into position. I first cut a section off one edge of the plywood to make it smaller and easier to handle. This would provide the clamping surface for the long edge of the cutout.

For the side edges of the cutout, I added a couple of hinged boards. I attached them using hinges because I knew that the steamed wood cools very quickly and I wanted to keep the hassle factor low for getting the form into position.

All three edges will be clamped once the form is in place. Here is the initial experiment with fitting the form in place. I have some scrap wood in there for spacing purposes but final wood has yet to be bent (more on that in a moment).

I am relating these tasks somewhat out of order from the actual accomplishment for continuity's sake. This afternoon, I visited a fellow builder, Skip, who is building a Mahogany runabout, a beautiful boat, I might add. He had offered to plane down my 1/4" material to the necessary 1/8" thickness.

Unfortunately, the wood had a knot in the very middle of the board. At first planing went well and we were getting close, however, one of the passes through the planer chipped out a section of the knot, leaving a hole. We discussed this a bit and figured that I could still use the material if I cut it and installed it as two pieces with a seam in the middle. A few more passes through the planer got the wood to the necessary thickness, however we did end up chiping more wood off of one edge. Fortunately the wood is wider than needed and this can be removed and still leave material for the end cap.

I was feeling a little out of sorts this afternoon and elected not to try and bend the material when I returned home, so that will be a task for another day.

Another task that needs completing is the making of the skeg. The skeg is a long fin running from a position somewhat forward of the aft end, to a point past frame 4, forward. It is approximately 11 feet in length. It tapers from 2 1/2 inches in height at the aft end to about 1/2 inch in height at the forward end. It is essentially a short fin to keep the boat from skidding when it turns.

The blueprints simply state that the skeg is from 10" forward of frame 4 to 9" aft of frame 1 (remember the frames are numbered from zero starting at the transom). In order to do this, I needed to determine where these two frames are on the hull exterior.

The approach I used was to hang a weighted string from the frames and mark their position on the floor.

Then using some extra lumber, I built a pair of vertical legs with a cross member and lined up the vertical legs with the marks on the floor. It was necessary to insure that the cross member was square to the legs and that the legs were 90 degrees vertical to the ground.

 Once this was in place, I marked the location, adjusted the mark for the various thicknesses of the wood and then added or subtracted the plan measurements for the skeg. These marks gave an overall length of 10 feet 8 inches.

This measuring jig will be useful later when I have to build the cradle to hold the overturned boat. I want the cradle to support the boat at the frames, so knowing their positions will be possible using this tool.

There were other tasks accomplished in the last two weeks, but for brevity's sake, I will save those for another day. So until next time, take care.

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