Progress

A lot of small tasks have been accomplished since the last post.  The photo to the right shows the installation of floor supports for the cockpit.  These outside supports were built as small I-beams with lightening holes along the vertical component.

The 12oz carbon fiber cloth finally arrived so I used some of it to reinforce the keel box.  I described the design of this critical component below and I think that it was actually strong enough before the carbon fiber was added.  However, the cloth went on very easily and molded beautifully to the shape of the existing structure.

The photo to the right shows curved edges for the cockpit that I built using 3/8" by 3/8" cedar strips.  The floor piece was cut some time ago.  I may need to add a bit to the edges up by the front of the cockpit where the cockpit sides curve quite a bit.

Top done for now

The cabin top is complete (for now).  All of the strips have been glued, and I have sanded and glassed both the inside and outside surfaces.  Unfortunately, some of the staple holes are quite prominent.  In retrospect, I should have spent more time figuring out the color of the filler for the holes.  Interestingly, the inside doesn't have any holes and looks beautiful.  If I were going to build a bunch of these, I would build an exterior frame and build the cabin top upside down with the staples on the inside.  Also, by dialing back the pressure on the air driven stapler, the staples would not drive below surface level and the overall appearance would be better.  I still need to put a couple of coats of epoxy on at least the outside surface, and of course eventually give it several coats of UV resistant varnish.  


I have the cabin-top on the boat, but I'm going to put it aside now until I finish the interior of the boat.  Next up, I have to glass in the hull side stringers, install the chain plate gussets, glass in the bunks, and then coat the whole interior with a couple coats of epoxy.  I'm planning on leaving the interior natural colored.  

Cabin top looking tip top

The strip pank cabin is taking quite a while (maybe 10 hours so far).  In any case, here is a picture as it looks today.  I need to finish the strips on the side, and then sand and fill the gaps and staple holes.  I'm hoping to glass the top this weekend, and then put the whole thing aside for a while so I can get back to the rest of the boat.

Keel and Cabin

 This weekend I've been working on the keel and the cabin on the boat.  It took quite a while to get the keel to be smaller than the NACA 0012 shape that is eventually going to be.  Once i got it down to size, I then used my hand planer to cut a 1/16" groove down both sides.  This grove was cut to accept two layers of 12 oz. unidirectional carbon fiber cloth.  The picture to the left shows the first side being laid-up.  The keel will be faired next, and eventually be wrapped in carbon fiber cloth.

 I started working on the cabin this weekend as well.  Instead of building the cabin out of plywood, the whole thing is going to be built using the strip-plank method using cedar strips with mahogany accents.  I'm planning on leaving the entire cabin natural and coating it with varnish.  Of course, if it doesn't come out as nice as I hope, I can always fair it and paint it.

To the left is a close-up picture of the first few strips that I've glued.  I'm using an air driven stapler to hold the strips together until the epoxy/filler mixture sets-up.  I'm stapling through small pieces of plastic so as to make it easier to remove the staples.


This picture also shows my first mahogany accent strip.

I glassed in the cockpit floor supports.  So far I have decided to not put in the bunks behind frame 124.  I think that the "trusses" that I put in there should more than compensate for the lack of the bunks.


I still need to put in stringers on the hull sides, install the chainplate gussets, install the bunks forward frame 124, and then coat everything in epoxy before I start working on the deck.

Keel box is in

 Memorial Day weekend - Sunday was the day that I was going to install the keel-box.  I had previously reinforced the floor of the boat between frames 110 and 124 with an additional layer of 1/4" hydrotek.  Yesterday I then glued on a template for the keel sleeve using a NACA 0012 shape.  The template was 2" wide by 14 1/8" and fit perfectly between the 110 and 124 frames.  

As the picture on the left shows, I then glued on the sides of the keel-box which were made out of three 1/4" ply laminated together (it would have been nice to have some 3/4" Hydrotek.  Note that I glued on some pieces outside of these boards so that i can create a recess in the deck for the keel top plate.

Once the Keel-box sides were in, I reinforced the floor of the boat further with another piece of 1/4" ply and then glued angled supports on to frames 110 and 124 which provide further support for both the keel-box and the floor.  If you zoom into the pictures you'll get a better view of these supports.  


Finally, I used the West System scarfer to angle the edges of the floor reinforcements so that there is a nice smooth transition.  


Next up for tomorrow, is to fillet and glass in all of the frames.  I had previously put mini-fillets on the frames to hold them in place more securely than with just the zip ties.  

More gluing and shaping

 All of the frames were stitched in, however after reading some of the entries on the i550class.org forum, I decided to remove the three center frames (89, 110, and 124) and double them up making each frame 1/2" thick instead of 1/4".  This should give me substantially more strength in the center of the boat where the majority of the stresses are concentrated.  While the frames are out, I filetted and taped the chine seams with glass biax tape.  I'm in the process of gluing on the shear clamps.  Once both sides are done, I'l put zip-tie the frames back in and then filet and tape the seams.  Should be done this weekend. 

In the mean time, I continue to work on the keel, and almost have the final shape set.  Of course, I'm expecting to have to do quite a bit of fairing with this item.  It will be a shame to cover up the mahogany with carbon fiber cloth.


The keel by the way uses a NACA 0012 shape.  I plugged the formula for a NACA foil into Microsoft Excel, and plotted the results.  I then adjusted the size of the plot in the spreadsheet until the print-out was "life sized".  I then used those print-out as a template for the foil.