Sure-fire center finder for firewood

I've found some of the most beautiful turning blanks in the firewood pile. The good news: It's free. Bad news: It's hard to find the center of odd-shaped pieces. So I've come up with this trick to solve that dilemma.

Mount a piece of scrap wood to your lathe's faceplate. Then attach a piece of acrylic using double-faced tape and chuck it in your lathe. Turn the acrylic to a disc. Use a ³⁄₃₂ " bit in a tail-stock chuck to drill a hole through the centerpoint, and then scribe concentric circles on the disc at ¹⁄₂ " intervals with a skew chisel.

To use the centerfinder, position it over the end of the stock, adjusting it until one of the circles is completely inscribed in the solid, usable portion of the wood. Then use a nail set or an awl to mark the center through the hole in the disc.
—Dick Ayers, Barron, Wis.