Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Wednesday, November 2, 2016

Cabin Profile Templating

These days, I am splitting my boat building time between several tasks to avoid burn out. One day, I'll do some interior filleting with epoxy, another day (or many), I will spend fairing the top structure in preparation for the top decking. And for the last week or two I've been working on getting the cabin side profiles transferred from the plans to a full size template.

In my last post, I showed some preliminary drawings of side profiles. In those I was attempting to see how the two different side profiles (original and my extended height version) would look. However, I was not satisfied with either of them and kept trying. Eventually I sketched out a design that I did like. On that sketch, I drew the scale 6 inch squares needed to transfer the design to the full size templates.

The process involves looking at the scale drawing and seeing where the cabin lines cross the scale squares. Then on the full size sheet (on which the 6 inch squares were already drawn), placing a point in the same approximate position on the same square. The squares on the drawings and on the full size template were numbered horizontally and vertically to aid in this process.

Well, transferring the drawing to a full size template is not as easy as it might sound because it is harder to see shapes and curves when they are up close and very large. Determining where the reference points cross any given square is a bit subject when converting it to full size. An inch down from a horizontal line on the full size square looks like 3/32 inch when the square is scaled down. However, these points do serve as useful references for sketching. Once the points are located on the drawing, then sketching and connecting the dots (sometimes) will yield the enlarged shape.

Here are two pictures after the first attempt. The blue tape helps to visualize the lines better.

 There are several things wrong with this initial transfer. The top of the cabin is too flat and the forward angle not raked back enough. Also, the shapes of the windows are not quite right, especially the forward and aft ones. The curve on the aft window should be more rounded and further down from the centerline of the window. And the forward window needs to be angled down more at the front. And the top of the cabin needs to be more raked down at the front to give a sleeker appearance. But this drawing served as a useful reference to work on correcting these deficiencies.

By placing tape in locations that needed improvement, I was eventually able to get a more pleasing shape. I used the tape as a guide for a sharpie pen and then used white paint to hide the incorrect lines. I also drew out the aft section of the cabin profile on a second sheet of poster board. By the way, these are drawn on 4 by 8 foot sheets of 1/4" poster board that I was lucky enough to acquire several years ago.

Then the shapes were cut out and placed into position on the boat. The idea here is to use these templates to work out any shape and size deficiencies, then transfer the designs to plywood templates. The plywood templates will then be placed on the boat to work out actual fit and installation concerns as well as determining how other parts will connect to them. Once that's done, I will be creating the actual cabin sides out of mahogany boards. However, that will be sometime in the future.

I have to say that I am quite pleased with the appearance so far. The templates are a bit rough in the curves, especially on the top, but when I transfer these to the plywood, I will use a wood batten to get a nice flowing curve to draw the profile with. In the last two pictures, you can see how the cabin sides junction up to the transom. The transom will flow up at an angle and into the aft deck.

Another thing to notice is the seam between the two templates. That is the approximate position of the aft end of the cabin (and where the helm station will be). In this area, I am going to be adding a laminated arch to allow the back of the cabin to remain open. So the plywood templates will be important in determining the final size and shape of that arch.

Finally, the lower edge of the templates are long at the moment. They will be trimmed to the lower edge of the carlings which the final pieces will be attached to.

I'll be going back to fairing the top structure. I have the port side done and the starboard side about 30 percent done. In this last picture, you can see how the side decking will eventually look in relation to the cabin sides.

Once the fairing is done, I am going to start working on mocking up the interior. Can't wait to get started on that. That's it for now. take care.

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