Monday, November 10, 2008

Improvisation

For me, part of the fun in making my own stuff is in finding alternative uses for everyday items, or alternatively, finding an everyday item to use out of context as a cheaper alternative for the 'proper' part.

The toggle eye I mounted into the bow of the kayak serves two purposes. Firstly, it must reinforce the hull and prevent the pull on the toggle rope from deforming the hull or pulling loose. Secondly, it must separate the hole through the hull from the airtight chamber formed ahead of the forward bulkhead. For this purpose, I employed a short length of 15mm copper pipe. I carefully marked the angles after boring a hole with a 16mm spade bit and cut the ends with a regular hacksaw. I scuffed the surface with 60 grit paper to allow the epoxy to key into the copper. The pipe is encased in a large block of epoxy/microfibre blend, which once cured, I filed back the ends about 1mm each side to be flush with the hull.

Kayak hatch covers are available from lots of outdoor, marine and specialist kayak shops, but the cost in the region of $100 upwards each. I don't need to use the airtight compartments ans storage, I just want to make sure they are dry, and if not (epoxy isn't totally waterproof, although it does take lengthy immersion to get any noticeable absorption) I need to be able to sponge out and air the compartments. To this end, I purchased a couple of 90mm storm water pipe covers. The consist of a short length of 90mm PVC pipe (about 70mm long) with one end open and the other covered by a removable, threaded cap. Again, epoxy wont bond to PVC and I didn't want to rely on simply scuffing the surface of such a large join. I think I read of the vague details of this process, but I made up the details myself.

Firstly I cut a length of glass tape just long enough to wrap round the pipe. I then cut it length ways down the centre. I laid 2 long strips of masking tape, sticky side up, on the workbench and stuck a half-width of glass tape to each, keeping the edges as straight as possible. I then piped a generous line of PVC solvent down the centre of each piece of glass tape. This was then wrapped around a piece of pipe, keeping the 'good' edge of the glass tape parallel with and just below the bottom of the threaded section. The masking tape keeps the glass in contact wit the PVC and allows pressure to be applied so that the solvent is partly absorbed in the glass weave. When I come to mount the pipes in the deck, I'll then add epoxy to the glass tape which will get a good bond with the part of the glass that is not already embedded in the PVC cement. The pipe and caps are grey, but I'll spray the caps with black enamel and any pipe showing above deck will be faired in with an epoxy fillet, primed and painted the same colour as the rest of the boat.

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