Drying red oak

[John Dowell]

I have some red oak that came off my farm and I saw milled it 1-1/2 yrs ago. It has been in a barn since then and it is stacked and separated with wood lathe. I had some 6x6 that was from the center of the trees that I wanted to make some leg blanks. I checked it and the moisture level still says 13%. How long does it take air drying? I have some 1-1/8" thick that I have had in my heated shop and it has been down to 6 to 8% for months.
I hate the thought of going and buying red oak when I have 1200 bd feet of my own. Would it hurt to rip up 6x6" into 2x2" for quicker drying, or would 13% cause it to twist and bow?
Any insight appreciated.
John

[Dennis Ford]

6" x 6" red oak will take many years to dry. The rule of thumb is one year for each inch of thickness but that works for 1 - 2 inch stock better than for thick stuff. I doubt that 6 years would be enough for 6 x 6 oak. If these beams include the pith, they will likely crack and warp before they are dry. I would rip them into 2 x 6 material or possibly 3 x 6 if it was mine. It depends on what you are looking for but don't expect defect free 6" thick oak at any price or drying time.

[John TenEyck]

If your barn is unheated, 13% is about as low as it will ever go, regardless of thickness. Moisture content is driven by relative humidity. 13% MC corresponds to about 65% RH, which is typical of many area of the country this time of year. The only way to get the wood lower in MC is to move it somewhere where the RH is lower. The wood in your heated shop got down to 6% MC because the heat lowered the relative humidity down to around 30%. Those thick beams will dry just fine once you get them into your shop, so I wouldn't cut them down if you need large beams.

[Scott T Smith]

There is no way that the core of a 6 x 6 red oak post will be at 13% MC in 1.5 years of air drying. The outer 3/4", yes, but the deeper you go into that post, the higher the moisture content will be. Most likely the core of those posts will be in excess of 35%MC.

If you're checking them with a pinless meter, they are only good for about 1/2" depth or thereabouts. Pin types require special, insulated long pins in order to take an accurate measurement deep into the wood.

Additionally, resawing is not a good option because if the posts were milled from the center of the log, you will have pith wood runing right through the middle of them. Oak pith is extremely unstable, and it will crack, and when you resaw your middle boards will split. The outer ones may not have pith wood in them, but you will have 13"MC on one face of the board, and probably over 30% on the other face, so they will move quite a bit as they continue to dry.

If you need larger diameter oak beams, planks, etc, it's best to have them milled w/o any pith wood, as this will help reduce checking.

In most locations, 1-1/8" oak will air dry down to 10% in about 8 months.

[Cody Colston]

There is no way that the core of a 6 x 6 red oak post will be at 13% MC in 1.5 years of air drying. The outer 3/4", yes, but the deeper you go into that post, the higher the moisture content will be. Most likely the core of those posts will be in excess of 35%MC.

+1

Those 6 x 6 posts will have to be kiln dried to get them dry throughout and even then, the pith will likely crack and check. Your best option for legs is to face-glue some of your 1 1/8" stock and cut out rift-sawn blanks. The grain will be straight on all four sides and the glue lines won't be very noticeable, if they are at all.