<html> At 11:07 AM 1/13/01 -0500, you wrote: <blockquote type=cite class=cite cite>Good idea Richard. I think I will try that. I have lots of old flanges laying around. My first trial there was to simply see whether a flange hole got bigger or smaller with increased humidity/moisture content. It is clear to me, contrary to apparent popular belief, that a hole in a flange decreases in diameter with increased humidity/moisture content.</blockquote> Terry, You need to remember my previous post, where I mentioned that there is some surface fiber swelling.  You should also remember my suggestions for testing - drilling the hole with the wood sitting in the shop at 50% RH isn't a good way to measure the change. If carried out properly with a larger change in humidity, the drill rod will become very tight in the center pin holes when the wood is dry.  Your test did not change the moisture content in the wood enough for such a small piece of wood to change shape, but it was evidently enough for a slight change in the surface fibers. As I originally suggested, you need to drill the hole when the wood is at one extreme or another, then test the fit when the wood has reached the opposite extreme. By the way, a closed container with water inside does not necessarily reach 100% humidity in the air, as you suggested.   That would depend on the temperature. Try it with a humidity gauge in there.  I suspect that the relative humidity went from your measured ~50% point when you drilled the hole, up to maybe 75% in the closed container.  With such a small cross section of wood, the amount dimensional change is not enough with such a small change in moisture content. I have done the exact same test you did with very definitive results.  Try again, but start with the wood either dry or wet - not in the middle.  Bake a few flanges in the oven at 250 degrees for and hour, then drill the holes right away when you take them out.  Check the fit after drilling, then check them the next day after the flanges reside in your wet chamber for a while. Don Mannino RPT </html>