If you want to be precise you will have to test what is called the core, and the shell, of the lumber (outside/inside). If the outside is dry and the inside is wet, then you are going to have a problem when you work it. You are looking for uniformity between the core and the shell. Lumber dries from the outside in. So there should not be a significant variance. Ideally you are looking for a kiln dried MC of 6-8%. This time of year, and depending on location, it should be running around 7-9%. So that will give you a target to shoot for. On wide boards, rip them close to the center(or whatever works in regards to establishing your call blank). Then check the inside edges, and the top and bottom face. Make sure you are back away from the ends of the board too, more in the middle. If you are working with Air dried lumber the MC will be considerably higher vs that of kiln dried. One thing to remember is that Kiln dried lumber will change according to it's environment. -It does not permanently stay "kiln dried". Ex. 80°F and 50% Relative humidity will cause kiln dried lumber to climb to 9% moisture content. Raise the Relative Humidity to 75% and it will climb to 14% moisture content. So storage is also important.
Dave
