Tuesday, August 11, 2015

Going Topless

Whew.  Been a busy...oh my, has it been 5 days? Well, at least I've been making some progress on the hardtop in between the rains. Oh, and if you were doing an internet search and came across the title, sorry to disappoint but this has nothing to do with drunk college girls on spring break.

The frame, or mold if you want to call it that, (the recent joke around here is it and my table look like a really nice roof frame and floor for a shed) is finally done. The last bit was to come up with the mounting surface at the back where the top will bolt on to the side of the arch. Of course, this means we finally had to figure out the exact angle we wanted the new top to have as it extends from the arch forward over the cockpit and the salon roof. The old soft top was multi-faceted due to the frame and came down far enough in front that it felt closed in and restricted visibility from the helm. Since the new top is straight, we needed to figure out an angle that would: improve visibility, look good with the lines of the boat, and not interfere with the boom.

The first step was to remove the old soft bimini.  It should be a simple matter of unzipping the cover from the frame supports, undoing a couple of ties, and sliding the back edge out of the bolt rope slot. Of course, this is a boat so it wasn't quite that easy. This is the first time we've tried taking the top down and quickly realized that this may be the first time it has been down since it was installed.  The zippers worked ok, but the nylon webbing ties had become, for lack of a better word, petrified in the Florida sun. Whoever tied the top on, in addition to using the D rings to hold it, tied knots with the webbing. It took prying the knots and then the D rings apart with a screwdriver to finally get them to release their grip.

Rover Topless.  Can you see the string?
The boat does look different without the top. Almost a bit sporty...like a convertible roadster. Once the boat was topless, we tied a string to the arch and took it forward to the mast so we would get an idea of the line of the top. We tried several placements and finally settled on one. We even had a boat neighbor who was passing by come give us his opinion, and we all agreed it would be a good look for the boat. It allows for plenty of room for the boom and adds about 2~3 inches more opening to look forward from the helm, and the line seemed to work well with the various lines and angles of the boat. So I took out my recently purchased adjustable angle square and measured the angle from the face of the arc to the line (this time the Harbor Freight tool did not disappoint).  As it turned out, it was exactly 60 degrees.  Interesting that our eyeball based determination resulted in a nice round number like that but I figured it was meant to be.

So, with that information in hand, I constructed a way of holding a board in position at that angle at the back of my frame/mold.  I took two pieces of plywood and attached them together so they would cover where it looked like the arch would intersect the 60 degree angle and then scribed the arch with a 4 foot long straight edge (another handy Harbor Freight purchase) using the existing arches of the frame as a guide.  I first tried using a small laser level to project the shape of the arch, but the levels I found wouldn't sit flush against the stringers and projected lines instead of points so the intersection was not accurate (and I couldn't find a simple laser pointer anywhere in town...I thought these things were sold out of buckets at cash registers just about everywhere a few years ago). I did use the laser to mark every couple of inches on the arches so I could keep my scribe perpendicular to them. After scribing the arch onto the angled piece of wood, it was cut at the appropriate angle with the jigsaw and sanded until the contour was identical with the rest of the frame. Sanding was a time consuming process of checking the area with the 4 foot straight edge ruler, hand sanding the high spots, and repeating until correct.

The newly installed angled mounting surface board.
The reason for needing this board to be accurate is that I will be using that surface to lay up the mounting tabs for the back of the arch against it.  Since this is a rather critical area in the "lets not have the top come crashing down on our heads" concept, I want to make sure it is right. I'm probably being a bit of a perfectionist on this construction, but I figure the more accurate the mold is, the better it will look and the less "corrective" work I'll have to do later.

Finally, the frame was built.  I took some cellophane packaging tape and "laminated" the tops of the stringers and the newly finished angled mounting surface board so that fiberglass resin would not stick to it.  I'm finally ready to start work on the actual top.  Well, almost.  Since this is my first time working with polyester resin and Divinycell foam, I want to build a small test piece to practice my techniques with these materials and try a few layup concepts before I dive in with $2000 worth of materials.

More on the test next time.  But I feel I'm finally making some real progress on this project.  At least more than just building a shed anyway.

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