January 12, 2007
Within deck progress
The deck came off of the hull quite easily - we had lined the hull with plastic and some duct tape so that dripped epoxy wouldn't bond our deck down to the hull. The Nimbus Hyak kayak hull temporarily went into the garage to make room for the giant upside down deck.
We knocked down the stair step edges of the Styrofoam slats on the inside of the hull, then rough sanded the whole foam core to a relatively uniform thickness.
I had previously calculated all of the areas that would require hard points, and marked them off with a felt pen, then gouged out the Styrofoam in those areas.
Hard points are areas of the deck core that are filled in with a solid substance to prevent fasteners and other thru-hardware from crushing the foam core. They also add considerable strength to those areas. Hard points are the 4 points around the canopy where I want to add hinges/latches, an area in the rear where the rudder is mounted, the bow and stern tips for a no-crush zone, the bow and stern for mounting cleats, and areas where the bulk heads will be placed.
The illustration above shows the location of the hard points and the 4 bulkheads - 2 small bulkheads 24" back from both the bow and stern to seal off areas that will be filled with solid buoyancy (expanding foam), and two main bulk heads to seal off the sleeping compartment and the bow storage compartment.
This stuff is a god send! Rather than spending an eternity mixing powered micro with epoxy resin, we purchased some pre-mixed fairing filler. It's just epoxy resin with micro-balloons already mixed in. It comes as a 2-part mix like Bondo and cures in a couple of hours. Great stuff!
Ben had the bright idea of testing the fairing compound first by filling in a typical 1/2" deep carved out Styrofoam hole to see if the exothermic heat created by the thick epoxy mix would melt the foam. It did as you can see. So, we ended up filling the hard point holes in layers to avoid dissolving any of the foam core.
I pre-cut all of the 18 oz fiberglass Woven Roving and Kevlar for the inside layers. These layers will wrap around the edges and fully seal off the deck. I will eventually bond the entire deck to the kayak hull, and add another band of fiberglass to bridge the seem on both the inside and outside. The area where the top and bottom (hull and deck) join should be pretty strong!
The plan for laying down the inside composite plies is to fully wet-out the deck edges and foam core with epoxy and wait for 3 hours until 'green' stage - this is where the epoxy has cured to the tacky stage. Then I will lay on my Kelvar. The tacky epoxy will hold the kevlar tightly around the edges of the deck. Then I fully wet-out the kevlar and wait another 3 hours for it to get tacky, then I'll lay down my final 18 oz fiberglass layer.
Here are some illustrations of the rudder. The rudder is a NACA 0020 airfoil 24" long x 4" wide. A 5/8" stainless steel tube is bonded into the rudder and runs up through the hull AND deck though a stainless steel housing tube. This housing tube is screwed and glues and glassed right into both the deck and the hull. The is a small bulkhead (not shown) behind the tube to enclose the solid buoyancy area. The tube is also glued and glassed to this bulkhead.
Control cables will be mounted to a swing arm clamped to the top of the rudder tube from ABOVE the deck (not shown). The cables will run through holes in the top deck to inside Within and run into the cockpit area.
I have a LOT to do, and I think I had better get moving on this. It's going slowly because I have only really been devoting one day a week to the fabrication. I've been busier training for Ironman Arizona which is in April - that takes up a few hours every day. Also I have been really busy working on a promotional video for the expedition designed to find some sponsors - along with a sponsorship package. That has been really great exercise for me, as it is forcing me to really think about the specifics of the expedition and what exactly I want to accomplish. Also I have started thinking about costs, other logistics and a rough schedule.
There is not enough time in the day! I've got to start getting serious about planning my time better.
I wonder if December of 2007 is too soon???..... Another year of development would be great, but I don't see the need to be sitting around. Might as well get the show on the road.