Structure

I was sitting in the lounge room a few days ago, looking at the coffee table that I made. I was sitting on the floor at the end of the coffee table, so I could see the end of the thick planks of wood that the top is made out of. And I started thinking about something my wood work teacher told me in high school. When building the top of a table, or a chopping board, or a wooden floor, or anything where you will be gluing solid planks of timber side by side to make a flat surface, you have you have to order the curve of the end grain so the surface stays flat and dose not bow after a few years.

If you look at the end of a peace of timber, you can see growth rings in it. There all ways curved, some have semi circles, some have a more gentle curve, but no mater what the all have a curve. This is called end grain. When making a table surface, you have to order the planks of wood so that the end grain of each peace of wood curves the opposite way to the peaces either side of it. So on the first one, the end grain would curve up, sort of like a happy face. The next peace of wood you would put with the end grain curving down, sort of like a sad face. After that would be another happy one, followed by another sad one ect...

Wood after a few years, tends to bow in the direction that the end grain curves. Using the happy sad paten when making a table top means that the wood is trying to curve in opposite directions and cancels each other out. So you end up with a flat table top. If you put all the peaces of wood as happy, the sides of your table would curve up, and every thing you put on it would slide to the middle. If you put all the peaces of wood as sad, the sides of your table would curve down, and every thing you put on it would slide off the side.

Its all about balance. If you are always completely happy, or all ways completely sad. Then structurally, your fucked...