Tuesday, 9 October 2007

Chine Runners

Well "Johanna" is still bottomless, but I've been working behind the scenes preparing for the final fitting.

I explored several possibilities on the best (easiest!) way to fit the chine runners. I have eventually decided on the following approach.

Initially I thought about roughly shaping the entire runner, bonding it to the hull and fairing off the top to match the chine logs. This would mean that I could then fit the bottom and the job would be more or less complete, bar the final sanding and shaping. When I came to do this I realised just how difficult it was to bend the runners to conform to the hull. My thoughts on it being easy to clamp evaporated because all the clamps did, was deform the "sharp" edge of the runner. Taking a hint from Jack Gardiner on the Paradox builders group I cut the runner into smaller blocks approx 150mm length and temporarily screwed them to the chine.

Chine runner "Blocks"

Blocks screwed to chine

I then faired the top (bottom) of the blocks to match the line of the chine logs.

Blocks being faired

At this stage I was prepared to glue all the blocks and fit the bottom panel. However my approach will now be to remove the blocks (they're all marked and numbered for easy repositioning), fit the bottom panel, glue the individual blocks back in place then shape and fair the runners. My main reasons for this order of construction is so that I can accurately measure the offset of the runners from the hull side. This would not be so easy if the runners were already in place. Also I have already built a drilling jig to mark the position of the ringnails in the centre of the chine logs. This relies on the jig fitting against the hull side, something else I would have to change if the runners were in place. Apart from all that, I was down to only 1 litre of epoxy. Now I'm pretty sure that that is more than enough to fit the bottom, but once I start it will be too late to find out if it isn't! I've had a delivery of another 9 litres today so we should be on a roll again. With luck I may have the bottom fitted this weekend.

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