The idea of “measure twice, cut once” is perhaps the oldest of woodworking maxims. But you still have to pay attention to the measurement.
I joked in an earlier blog that it doesn’t matter how many times you measure, if you can’t remember what you just measured long enough to make the mark in the right spot. The culprit there, I suspect, is just lazy thinking and not really paying attention. You measure 6-3/8”, but when you go to do something with that measurement you think, wait, what was it again?
But sometimes the measurement itself is the culprit, especially when that measurement is a component of yet another measurement. For example, my wife gave me a night off from kitchen duties last Saturday, and for her lasagna recipe she needed 4 cups of spaghetti sauce. I was baffled at the grocery story when I couldn’t find a jar of spaghetti sauce that had 4 cups. Plenty of them that were 32 ounces, but since a cup has 6 ounces, I needed a 24-ounce jar.
I know, and have known for decades, that there’s 8 ounces in a cup, but for some reason when looking at all those jars the measurement of 6 ounces to a cup popped into my head and I never questioned it. At that point, the measurement was cemented in what passes for my brain, and I just oh-yeah-sure looked for a 24-ounce jar. Naturally, I didn’t find one, and so bought a 32-ounce jar, figuring there’d be leftover sauce. Inadvertently, what I got was perfect.
This kind of thing is easy to do. How many inches in a cubic foot? Easy, 144. Nope, that’s a square foot. How about degrees in a right angle? It’s 90, not 45. I know better. You know better. But when not paying attention – or paying more attention to another aspect of a project – it’s easy to grab a figure that’s correct for something else, but not for what you’re doing. Then, for lack of a better description, you just go with it without another thought. Of course, everything you do past that point will be wrong. But don’t feel bad; even NASA does this on occasion, so you’re in good company.
Of course, when NASA did it, it cost $327 million. For you and me, it usually means just cutting a new piece of wood.