Due to last years Hurricane Isabell I have accumulated a substantial amount of fresh cut pine and oak boards. None of them have been to a kiln to dry out. What are the disadvantages of using these boards for interior construction? I am considering using them for finishing a basement.
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what is their MC?
Moisture
Content
...
just taking out the middle man ....
JeffBuck Construction, llc Pittsburgh,PA
Artistry in Carpentry
Moisture content is extremely high. Just cut the boards 3 weeks ago. Stacked them with slats between to dry out. Full of sap as we speak.
I made my window sills from a oak tree that was once in my back yard.
Hope you pruned it beforehand.
I never met a tool I didn't like!
I live in Minnesota so what I tell you isn't terribly accurite. Oak wood dries to a usefull working level in about six months per inch. at that point you are below about 12 percent moisture and for exterior use that's dry enough.. Pine wood will dry to about the same in about a month..
Interior/ furniture and it's a whole new game. What you want is wood that gets below 7 percent moisture and in Florida that will be pretty hard to achieve.
Let me clarify things a little more.. Really well dried wood will probably be above that 7 percent moisture. the reason it's brought down to that level is to get all the bond water free in the cells, then the moisture in the air won't affect things as much.
Frenchy,
I have a question for you, one I have never put into words until now, but your reply above stimulated my thought process.
Suppose you cut down an oak tree, and saw it into 4/4 planks, which are air dried to 12% MC. Then half the wood is kiln dried to 7% and the other half is left in the shed, at 12%, which is equilibrium moisture content in that shed.
After the one batch is kilned to 7% MC, you store it back in the shed next to the other batch. It all sits there for the next ten years, stickered and ventilated. Here comes the question:
Part one: Does the kiln-dried pile re-equilibrate to 12% MC?
Part two: Does the formerly kiln-dried stack behave differently than the air-dried stack, after the decade is up and both are converted to furniture, trim, and cabinet components? Does it in some way "remember" having been kiln-dried in its early afterlife?
This is a serious question I have pondered for years and do not know the answer to. Logic suggests one answer, but wood defies logic all the time, so I don't trust that instinct. Please enlighten me if you can. Thanks.
Bugle
Yes it will quickly return to 12 % moisture. your second question is a bit harder.. Over time the wood will lose it's bond water to be replaced with "free" water that moves in and out of the wood. going from 12% MC with bond water to 12% moisture "free" water is stressfull. If a board were to be fastened firmly across something (say the cover of a box) there would be a tremendous stress on the board possibly causing it to split. Once free of the Bond water the possible shrinkage of the wood (due to drying out in an airconditioned space for example) isn't as stressful
There are formulas for the above and if it weren't really late I'd look them up and give them to you.. if you really want the numbers, e-mail me tomorrow and I'll do the research..
One point if you keep that wood in airconditioned spaces it will get much below 12 % moisture quickly.. Some kilns are really dehumidifiers...
Frenchy,
Thanks for your reply. What I am after is more of an understanding of the mechanics of the difference between "bond" and "free" water in a piece of wood. Until I have that concept clear, the numeric values are of lesser use to me.
You said, "Once free of the Bond water the possible shrinkage of the wood (due to drying out in an airconditioned space for example) isn't as stressful." Is the bond water in a different part of the tissue than the free water? I get a sense of the former existing inside the cells, and the latter in the interstices between the cells.
Thanks again.
Bugle
Close enough, actually a pretty accurite description.