I've been out killing fish and have not stopped in for a couple days and am heading out again real soon, but have a few things to add here. Hope I have not stepped on any toes too hard.<P>Oil, even cured completely has an affinity to water vapor, actually frank water as well; therefore the admonition not to put wet cups on the oil finished side table at Grandma's house. It will only absorb a given amount, and then no more, if it is used as a ship finish. Some will migrate through the finish and be absorbed by the wood, but if the wood is always wet it simply reaches an equilibrium point and stays there.<P>Now when the same piece of oil finished wood is out in the air and subjected to constantly changed relative humidity it takes up and gives off water all the time. And because the relative humidity never stablizes, it is always moving.<P>On the linseed oil thread under gunsmithing I think I remember going into more detail about it.<P>I hope is was understood I was not suggesting a piece of unfinished wood would soak up less frank water than a piece of oiled wood, because that is clearly not the case.<P>Sheister made some excellent points about highly-figured woods moving around more than straight grained woods, but one very nice exception is tight fiddle-back figure which actually is quite a bit more stable than straight figure. Fiber lengths are longer, the wood is harder and stronger, in curly, than the same species when it is straight.<P>The logic of finishing different areas of a stock differently escapes me, also.<P>Another concept which helps understanding wood and water is the difference between bound and free water. Green wood is full of water, sometimes as much as 200% (water content is usually measured as a per centage of the oven-dry weight of the piece of wood. Hence a 1# oven-dry piece which weighed 2# when wet had a moisture content of 100%)<P>When the wood is dried, free water leaves first. It is what is inside the cells, vessels and interstices. This water removal does not affect the size of the wood, therefore there is no warpage as the free water leaves. At about 25-35% the bound water starts to leave. It was electro-chemically attached to molecules of lignin in the cell walls, or solvent for various extractives in the wood, mostly in the vessels.<P>The removal of bound water is where the going gets tough in wood drying as this is where rot and stain often occur and where drying defects start. If the wood dries too fast the surface gets dry enough to take a set and when the inside dries it shrinks and causes stresses, up to and commonly including honey-combing inside the wood.<P>Different woods dry differently for a million different reasons. The biggest reason for the differences is the pore size of the wood; gums, resins and other extractives present in those pores; figure, grain run-out and knots; thickness of the blank and many, many more. <P>The one thing Sheister said which I hope is a misunderstanding is the moisture content of his blanks. A piece of wood reaches atmospheric moisture content outdoors of about 12-15% (vs. oven-dry) but then needs to be dried to 6% and then if kept there for quite some time, years help, the wood will stablize at the lower moisture content and become much more stable, even with bigger swings in moisture content. <P>Each time a piece of wood cycles, even over a range of a per cent or two of water content, it reduces its tendency to move. That is why old stock blanks are prefered over more recently cut ones.<P>Sheister is absolutely correct about an oil finish being the right finish for the custom guns and the nearly uniform use of them by the high-end gun makers. Two points here though; my finish looks just like them, because it is an oil finish; these are the same guys who often call glass-bedding heresy.<P>This has rambled and gotten much too long, thanks for bearing with me. No offense intended or taken.<BR>art
