Jon, Take a piece of wood with a moisture content of 10%. Drill a hole in it of a specific size. Reduce the moisture content to 8% the hole in the wood will shrink in diameter. Increase the moisture content to 12% the hole will be smaller than at 10%. In the first case the wood shrinks to reduce the hole size. In the second case the wood swells to reduce the hole size. Strange but true. It can also increase in size if the change in large enough. Teflon is a sealed cell plastic which cannot absorb or give off moisture. What you observed was a change of the wood moisture content which changed the shape of the hole, in your case, enlarged it. I hope this has confused you enough. Newton
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