>At 11:31 AM -0600 11/11/03, Ron Nossaman wrote: > >. . . Looking at individual planks that have twice the number of >annular rings per inch at one edge that they have at the other, I've >wondered what the difference in moisture transfer rate might be >between the two, if there is any difference. Have you ever tried >this? Hi Ron N. and all, A couple of observations from my recent period of sound board development. I haven't measured the variable drying rate between planks of different annular rings densities either, but I'm sure that it does occur, since the variation in density will inevitable cause the moisture loss rate to vary. When we built test strips of CC sound board for bench loading, I noticed that the resultant crown radius varied according to the annular ring spacing of the segments that made up the sound board panel strip. The closer the annular rings, the smaller would be the crown radius. This stands to reason since the strips with closer annular rings, with higher strength, would be more effective in bending the rib into a crown. The grain orientation in spruce also effect its drying rate. If all boards in a panel are accurately quarter cut, then they will tend to dry at a more even rate. However, should some strips be cut off the quarter, those strips will tend to dry more quickly since the medullary ray will be angling out of the face of the strip instead of running parallel to the face of the board. Furthermore, this problem also occurs with accurately-quarter-cut lumber when it is being dried in the stack. When a board is accurately quartered the medullary ray will be parallel to the wide face of the board and perpendicular to the edge of the board. Therefore, if the edge of a quartered board is not treated with a coat of something before it is stacked, there is more likelihood that the wood towards the edge of a board will suffer degrade during the drying process. Regarding moisture meter alternatives, I think Ron N's. is the best I've seen to date. An image can be seen at; http://tinyurl.com/u4ah Ron O. -- OVERS PIANOS - SYDNEY Grand Piano Manufacturers _______________________ Web http://overspianos.com.au mailto:info@overspianos.com.au _______________________
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