Q: Is it possible that a piece of Elliota pine wood shrinks by 1/16 inch during an ocean transit time of 25 days? The pieces are originally 7/8 x 7/8 x 79 inch length, S4S, KD. They are 12 percent MC, bundled and shipped in a 20-foot dry container from South America to the United States (New Orleans). Is it possible that the pieces dried and shrunk in transit? They measured 13/16 x 13/16 inches when they arrived in the United States. Could the equator heat be a possible answer?
A: Heat does not change the size of wood. Only MC change will change the size. However, in a closed container, there would be little chance that the wood will change MC at all, because it is impossible for substantial moisture to leave or enter a tight container. In other words, in a closed, tight container, the MC change is usually 0 percent MC no matter what shipping route is used or weather is encountered.
Note that a size change of 1/16 inch in your pieces is about a 6 percent size change. It would require at least a 24 percent MC change to cause this much size change. With such a large moisture change, you would also see substantial warping and maybe even fungal staining. Further, with such a large moisture change, you would also notice that the size would be different in width and thickness, due to substantial difference in radial and tangential shrinkage. That is, if they did indeed dry after manufacturing, your squares would now be rectangular in cross-section and not square. Because both dimensions are the same, I conclude that it was manufactured to the wrong size and has not changed MC.
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