Moisture content of red oak

[DonT]

I recently had some red oak milled into 1x8 lumber.The moisture content is presently above 25%(highest my meter will test)my question is how long will it take to air dry to a moisture content low enough to use?   Thanks DonT

[Ron Wenrich]

It depends on what you are going to use it for.  Rule-of-thumb is about 6 months per inch of thickness.  But, that won't put it down to the KD 6%.

[DonT]

Thanks Ron,I was looking at a book shelf,or dresser for my daughter.Would a year dry it enough for this?  DonT

[Ron Wenrich]

Okay, you're making me break out the books and read up on drying.   :P  

The first thing you should do is end coat the lumber.  Parrafin, aluminum paint or urethane varnish will work well.  It has to be something that is relatively impervious . This will cause the lumber to dry through the surface, instead of out the ends.  It will also limit fungal spores.  

Next, you need to stack your lumber on stickers.  These are small sticks placed between the rows of boards.  They should be no more than 16" apart, and be put as close to the end as possible.  Stickers must be lined up in a vertical row.  Otherwise you'll get wavy boards.

Put a cover of plywood or low grade boards to protect the top layer of boards.  If the bundle is small, you may want to add weight, like cinder blocks or bricks to the cover.  This will help put weight on your boards and provide restraint on the lumber.

Chose an area that allows for moderate drying, at first.  This can be anyplace that allows an air flow.  Outside is OK, as is an unheated garage.  Make sure that the lumber is high enough off the ground to avoid dampness.  Do not put in an overly breezy area.  This will cause some pretty rapid surface drying which will cause season checks.  

For wood that is to be used indoors, you will have to finish the drying indoors.  You need to get the wood down to an equilibrium in the environment it is being used.

Approximate drying time for 4/4 red oak is 80-250 days.  This will get it down to about 20% moisture content.  The shorter time is for spring/summer drying.  No drying will occur when the wood freezes in the winter.  

[Brian_Bailey]

DonT,  

Wood that is going to be use indoors as furniture or cabinets should be dried to approx. 8% mc before you start making things out of it.

Ron,

Wood continues to lose moisture even when it's frozen, although slowly.  The process is called Sublimation.  The water becomes a solid (ice), then evaporates (gas) without going thru an intermediate liquid state.

[DonT]

Thanks for the help Ron and Brian, sorry for the book work Ron,I had already painted the ends,stacked it in my unheated garage,stickered every 25cm,and piled some bricks on top so I guess it is just a waiting game now. Thanks again for the help.  DonT

[Don P]

I'm married to a very kind and patient soul who puts up with alot...me for instance : ;D. I try to bring project wood into the house...ok into the living room for at least one winter before using for any fine work. Equilibrium in our wood heated house in VA through the winter runs 8%. My routine is to sticker in the sawshed, under roof but open sided. Move to the upstairs of the barn, with high gable vents, then finish indoors. Like everyone a kiln is on the list, but this works for me.
Search the forest products labs publications for drying hardwood lumber and air drying of lumber, I think they have them in pdf format.

[Tom]

Don, DonT forget that one of the most important things in drying wood is air movement.  Too  little won't move the wet air out of the stack. Too much might help to cause cracks on the outside of the board as it shrinks around the wet inside. Still, you must get an air exchange to clear the wet air and bring in dry air. Sometimes a fan is in order.  If you stacked up against a wall then you definetly have dead air.