Friday, January 8, 2010

How do I measure thee? Let me count the ways.



Jan 10- Yesterday afternoon I was readjusting the transom mold, which needs to be at the right spot fore and aft, plumb on its centerline, in line with the other molds’ centerlines, and at the right angle of rake. Then it has to sit still while being screwed to the strongback. All assuming it was cut to the right size and shape to begin with, not automatic since the plans do not detail it. Each time I thought I had it right, I cross checked it by measuring how high the chine edge sat and how far it was from the next mold vs how high the plan says it should be. Of course, the cross check never quite checks, and I had to decide what to adjust, shim, fudge, compromise, or ignore.

But wait, there’s more! As I sat in the “moaning chair” planning my next move, I remembered that the plans are drawn to the outside of the planking, but the molds shape the inside of the planking. I knew that, and had allowed for it by taking off 6mm from the mold sides, but I had not done that to the bottom (the top as it sits upside down on the strongback). So all the molds were cut too high by 6mm., and they all would have to be trimmed. Time to quit and pour myself some rum.

Later in the evening, I realized that my problem was actually an opportunity. I can trim the molds with the power plane, and correct for the planking thickness and for any existing inaccuracy at the same time, and get them all to just exactly the height they should be. Why, I should have done the same thing with the sides, cutting them a bit wide and trimming them after the molds were mounted.

I couldn’t do much today because of a misty rain, but I did remeasure all the molds in preparation for trimming them. I’ll do that tomorrow if weather permits- the forecast warns of possible snow, which we haven’t had in 30 years. Where’s Al Gore when you need him?
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