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| Spiling batten in place for strake #2 |
In some ways, the garboard may be the most difficult strake, aside from the shear strake, because it is wider, and requires forming to the keelson with its varying widths and bevels. However, once the next strake is in place, the garboard will have no visible edges from which to assess the fairness of my cuts, and it will not be visible at all once the boat is finished, at least not when she is in the water (one hopes.) All in all, it's an advantage to be able to get used to the new (for me) planking techniques where any residual errors will be the least apparent to others.
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| The second plank clamped in place for fitting |
My glue-up process consisted of, first coating the inner surface with non-thickened epoxy (West System), then using well thickened epoxy to give a complete bond on the mating surfaces of the plywood, the keelson, and the frames. I was careful to leave space between the frames and the garboard strake for water to move freely from stem to stern. I glued the scarph joints in place on the hull, as Oughtred recommends. Working alone, I can't imagine doing it any other way.
The view is from the stern. I am alternating my starting points (garboard started from the bow, second strake from the stern, etc.) in order to stagger the locations of my scarphs.
gday Charles, AA here - just a question on how you went with your frames and laminating of. I have got about four done now and its frustrating to judge springback to say the least. Did you try to guess it or just stick to the lofted line when setting the clamping blocks, then pull the frames into line when mounting on the moulds? BTW You're doing a hell of job getting on with it, you should be on the water before the years out I reckon !!!
ReplyDeleteRegards Aussie Andy
Hey Andrew,
ReplyDeleteGood to hear from you. Springback is definitely a problem with the frames. I have read several recommendations to over-bend the frames when you clamp them for glue-up, but like you, I didn't think I could reliably figure out precisely what that extra bend should be, especially where your curve is not constant.
I dealt with the problem in a couple of ways. First, as you say, you can force the frames into position using clamps to draw them in, when you fasten them to the moulds. Just use lots of blocks screwed to the moulds, positioned precisely the thickness of the frame from the edge of the mould, and crank away with your clamps. This helped me align them pretty well, solving about 90% of the problem, but there were still some places where the frame was either proud of the mould for a few inches, or else was too low. The proud ones are easily leveled with a plane or a grinder. You can do it when you are fairing your frames. If you feel you have had to remove so much of a frame that its strength is compromised, just glue a strip to the inside to make up for any loss of strength.
The low frames, I built up to the level of the moulds by laminating additional strips on top of the mould-mounted frame, to at least bring it up to the level of the mould. Later I planed or ground them down to a fair curve.
One of the liberating features of glued laminate construction is the ability to add wood when and where needed without compromising structural integrity.
Thanks for the kind words. I don't expect to be in the water anytime soon, however. My goal is to finish planking the hull and have my flip over party before the weather turns too cold to glue.
Cheers
Charles