Wednesday, April 05, 2006

Steam Bending and Gap Filling

Things have been pretty slow going around here recently but I have gotten a few things done.
  1. I rough sanded the deck.
  2. Last week I cut out the cockpit hole, so the boat, again, has a hole in it. This is as far as I'll take the cockpit until after the deck has been glassed.
  3. I cut another hole in the kayak, this one is a circle of about 4" or so in diameter and is located just fore of the cockpit and was cut to accept a carved feature I made for insertion in the deck (more on this in a subsequent post).
  4. I finished the carved feature mentioned above and after a great deal of mucking about with it, inserted the carved piece with walnut center into the kayak deck and glued it in place.
  5. More sanding on the deck.
  6. I made a fairing board for sanding by attaching handles to a piece of 1/8" hardboard sized to accommodate a layed out sanding belt (from a belt sander). This works well, I should've done it sooner.
  7. I built a plywood box for steam bending the walnut strips which are to become the external stems (bow & stern).
  8. I screwed around with an old electric kettle to get it to work properly for the steam box. First I had to bypass the thermostat so that it would continue to boil for the necessary time. Second, I had to come up with a pipe set-up in order to carry the steam into the box. It seemed that the steam would have rather gone anywhere other than into the box (no, the box was not sealed too tightly) prefer to escape at the several weak points in my system. The final set-up used a PVC pipe (1 1/2"?), duct taped to the kettle with a second piece of pipe (2"?) slipped over top and a third piece (1 1/2"? again) which fit inside the larger piece, giving a telescoping arrangement. The pipes were sealed with duct tape, and sealed to the box with duct tape. Too bad duct tape sucks with respect to resisting steam. Oh well, it worked long enough to hold in the steam for 20 minutes or so at a time.
  9. I made forms to replicate the shape of the stems on which to bend the steamed walnut stems and hold them while they dried.
  10. I steamed the walnut, bent it around the forms, and clamped it in place for it to dry overnight.
  11. I mixed up and applied some thickened epoxy to fill the gaps on the deck, using a light yellow mixture as shown in an earlier post for the alaskan yellow cedar section of the deck, and a brownish mixture for the western red cedar section of the deck.
  12. I learned that if you mix up ~2 ounces of epoxy (1 pump resin + 1 pump hardener) and let it sit in front of the heater for a couple of minutes so that it becomes warm to reduce the viscosity, it will get smoking hot (very literally) when it begins to "kick". It seemed the perfect consistency when I started to use it to coat my carving (I wanted to ensure it would flow into all the nooks without trapping air) but I was really surprised how quickly the epoxy went from a thin liquid to semi-solid. Although I managed to get the carving mostly coated before the resin became unusable, it was only barely and I didn't fill all the valleys as I planned (no problem, I'll get it on the next go around).
The next few steps will be to scrape/sand off the excess epoxy putty, sand things smooth again, glue the stems in place, shape the stems, fill gaps on the hull. At that point, I think I should be ready for glassing.