The handy dandy Shrinkulator
Now all I need is a laptop in my shop… –dan
One of the things most beginning woodworkers don’t realize is that wood moves through out the year. Table tops and other wide pieces can easily change size by 1/8th inch and back through out the year. Wood also moves much more across the grain than with it, which is why you have to be careful when you join two pieces of wood with the grain running different directions. It’s also why you should always finish the front and back of all wood the same way to avoid warping.
Want to get an idea of how much that table top or panel will move? Check out the handy dandy Shrinkulator. Enter the high and low relative humidity for your area and the type and dimension of your wood and it will calculate the change in dimension along the growth rings (flat sawn) and across the growth rings (quarter sawn).
BTW, you can find the relative humidity for your area here or use a moisture content of ~4% to 10% for most situations.
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