Portable Milling Service

Hardwoods, like oak and hickory, air dry at an average rate of 1″ per year in NC.  And that is only after they have been sawn.  Logs on the ground will rot before they dry.  For instance, a white oak log that has been on the ground for a year will be just as “wet” as it was when it was felled.  Only the cut ends will show signs of drying, called “end checks” or “checking”, if they haven’t been sealed.  A couple of fresh end cuts will usually remove most of the checking and the ends can be sealed at that point – assuming that there is still enough length left in the log to achieve your goal (e.g. 8′ or 12′ lengths). If stored off the ground, an oak log can resist rot and remain intact for several years – especially when the bark is removed.

Softwoods, like pine, are not so resilient. You should have a plan for milling before the trees are felled. If not milled withing 4-6 weeks of harvesting, pine logs will develop blue streaking that will run throughout the log. Blue streaking is an indicator that a fungus has been introduced to the wood by a pine beetle or other wood borers and that the decay process has started.

Sawing logs usually produces only about 60% of usable lumber from the total volume.  The center, or “pith”, contains juvenile wood that should not be incorporated into your lumber if you plan to use it in an interior, climatized application.  This usually results in an approx. 4″ square cant that is discarded and used for firewood, etc. The sapwood, which is directly behind the bark, will also be removed and discarded when squaring the log for milling.

You will have to prepare a location to stack the lumber for drying.  When stacking milled lumber, there are a few things that should happen.  Start with sleepers similar in strength/size to a 4″x4″ to begin the first row of the stack – spaced every 2′ and at each end.  So, an 8′ long stack would require five sleepers – leveled.  The stickers that separate each row of boards will need to be installed at the same intervals, directly above the sleepers.  Unless the stickers have been kiln-dried, they will stain the wood. 

Milled wood will need to be covered.  Using a tarp is not recommended.  A tarp will prohibit proper airflow and promote mold growth on the wood.  Something more suitable to hold up to the weather and wind, like sheets of old roofing tin, is the best way to protect your investment if you don’t have an open-air shed to stack lumber to dry.  A piece or two of metal, along with a few cinderblocks to weigh down the top row of lumber, will keep the rain off and still allow for proper air flow.

Milling time varies depending on log size and species, as well as board size. Two-inch thick, full-width slabs don’t take as long to produce as 1″ dimensional lumber from a squared cant. 

Spalting is caused by fungus beginning to break down the wood at the early stages of decay.  It must be sawn at just the right time to get the patterning while still retaining the integrity of the wood.  That is why spalted maple products commands higher retail prices. Some common wood species for spalting in our area include maple, pecan, poplar and sycamore.

If you plan to use your lumber in a climatized, indoor space, it will need to be kiln-dried to kill any wood-boring insects and to finalize the drying process.  Air-drying may take up to a year and will usually only take your lumber to between 12% and 16% moisture content (MC) in NC.  Lumber for fine woodworking should be kiln-dried and needs to be in the 6% – 8% MC range.  Board and slab thickness, when sawn, will need to accommodate for the drying shrinkage and planing loss.  Usually, this will be anywhere from 1/4″ to 3/4″ over – depending on the board thickness and species.

The drying process will inevitably cause some bowing, etc. in the lumber – even with strapping or weighing it down.  After drying, the wood will need to be straightened and planed before it is used in finishing carpentry applications. 

Currently, we do not offer kiln-drying services. However, we can facilitate the handling and transport of your lumber to/from a local kiln.