Original Posted By: owner-pietenpol-list-server(at)matronics.com
When we have wood with the grain running 90 degress or so to on surface, itis easy to see that the grain does not run off the piece of wood. With thewood you propose to use, there is an allowable slope to both the verticalgrain and the flat grain and you will have to do a calulation to see thatthe ACTUAL slope is within limits. Minimum allowable grain slope is 1 in15. Actual slope is computed by taking the square root of the sum of thevertical slope squared plus the horizontal slope squared.If horizontal slope is 1 inch in 26 inches and the vertical slope is 1 in 20then we have:square root of ((1/26)(1/26)+(1/20)(1/20))= square root of .0039 = .062 and1/.062=16 so the actual slope of this example is 1 inch over 16 inches andthe piece is good.Not taking this calculation into account with any old knot free wood withthe right rings per inch is risky.Look in your EAA WOOD book for the article by Noel Becar on the Selectionand Evaluation of Woodchris BobkaTech Counselor-----Original Message-----