Beside aspects such as type of wood and dimensions of the logs, the moisture content plays an important role. The more conventional way to stack wood for air drying is to build the stack in layers, with a 1/2” to 1” gap between the boards, and 1” thick stickers between the layers to allow air flow. Some people stack the wood in tall rows where it has been cut and fix a small roof over the top and leave it to season like that. Once cured, it is virtually impossible to disassemble a Gorilla Wood Glue joint without damaging the surfaces. Ideally, wood is dried to that equilibrium moisture content as will later (in service) be attained by the wood.
This resourceful guide is designed to provide you with basic information on kiln drying and discuss the many advantages of drying your own lumber. But overcoming the challenges involved in air-drying wood often rewards you with more stable wood, as the wood has more time to work through the process and develop any inevitable twists and bows it might have. If you are involved with lumber drying and its management and want practical, hands-on training and knowledge, this course has something for you.
Proper sticker alignment allows air to circulate evenly across the surfaces of the lumber and allows a more uniform drying rate for each piece of lumber. There is an extensive volume of literature relating to the chemical modification of wood (Rowell, 1983, 1991; Kumar, 1994; Haque, 1997). Engineered wood floors are made up of multiple layers of wood veneer glued and pressed together.
Otherwise you are mostly guessing, a year is good for some woods, especially if it has air circulating, some like oak need closer to 2 years air drying. If you’re planning to use your carport or garage to air dry your stack, it will take longer due to lack of air flow. A selection of sizes from three to six inches in diameter for wood stoves and an inch or so larger for furnaces will probably serve you well.
Finding wood that remains flat is a tougher problem than finding flat wood (one solution used is to glue pieces together to reduce bending). In situations where green wood is to be processed into usable boards, (especially in the case of thicker lumber), a kiln is frequently used to control the drying process. It is important for wood floor owners to understand the behavior of wood in relation to moisture. At Byler’s, we are here to help you find exactly the right piece of wood for your indoor application- whether for home improvement or artistic purposes.
I love starting the 200th fire of the season almost as much as I love starting the first; and as for the bone-soaking heat of a wood fire, the faint perfume of woodsmoke in the winter air, the magic of embers in the night — well, you won’t get those with your forced-air gas furnace, no matter what its website says. When the wood seasons it should be protected from direct rainfall and should ideally be on a dry base. Nevertheless, with only a few weeks’ worth of drying time I have seen very green wood in a holz hausen dry out until it cracks.
Pin-type meters, in particular, have the advantage of being able to tell you the depth at which a moisture pocket in wood occurs. Logs are aged whole and then sectioned to order with a big cordwood saw, split with a hydraulic ram, and moved by conveyer belt into trucks with one-, two-, or four-cord-sized beds that will dump the wood in your yard. The venting and reheating of the exchanged air consumes up to 80% of the energy required to dry lumber. Often the fans are reversible in order to achieve more uniform drying in the charge.
These parameters are changed in a series of steps called a schedule, which encompasses the active part of drying. Below 12% – Readings in this range are common to kiln or oven dried woods and furniture grades of wood, and represent dry conditions. Measure the wet-bulb temperature by placing a wet cotton wick over a conventional thermometer. Also, the maximum temperature is somewhat lower and the water condensate may contain unwanted chemicals.
Heated air is circulated over the wood, and the water on the wood surface evaporates, raising the humidity of the air. A wood’s MC is also a dynamic exchange between the wood itself and the surrounding air. Wood is often sold wet and green — right off the stump — or aged for just a few months. The drying conditions are successively varied from time to time in such a way that the kilns provide control over the entire charge of timber being dried. Thus, you not only want to find flat wood, you want to find wood that remains flat.
I have had success taking wood down to 6% in mere minutes by microwaving very small pieces of oak in the kitchen microwave a few pieces at a time (a lot of trial and error getting the timing/settings just right for my wattage of oven of course the microwave heats the water on the inside and you then set the wood outside the oven to dry while you heat the next batch; test and repeat until you get it).
The main advantage of a kiln is that with the increased temperature and airflow—all while carefully maintaining and controlling the ambient humidity—the wood can be dried much more evenly, minimizing any sort of moisture gradient between the outer shell (which dries very quickly) and the inner core (which slowly equalizes moisture with the shell).
A wood moisture meter is crucial in establishing and maintaining healthy wood MC levels at each stage of lumber production.A wood moisture meter is a tool which measures the wood’s MC. As green wood circulates for processing in a mill, in-kiln and in-line MC systems measure and document the wood’s MC and track the efficiency of the kiln-drying process.
Would love to get some hardwood at the prices mentioned in the article, but where I live in So. Oregon softwood is the only wood available locally, so I burn ponderosa pine and juniper ($125.00 cord in rounds for pine and up to $225.00 cord for juniper.) Lots of beetle kill pine is available, but the buyer has to be careful as ants invade the dead trees quickly.
The natural air-drying of lumber can be a long process, so oftentimes lumber will be kiln-dried to speed the process -drying is basically a process of placing sawn lumber into kilns where heated air is circulated and the temperature and RH of the kiln is controlled for the purpose of reaching the wood’s equilibrium moisture content (EMC): a balance between the MC of the wood, and the RH of its surrounding environment, depending upon the end wood products application specifications.
The way to determine water content is usually by jamming an electronic probe into the side of the board on an inconspicuous surface, but if you know how much your wood should weigh dry versus wet then you can determine water content by weighing it. I suppose that tip is more useful for people using very small pieces of wood who don’t want any surface marred by test probes.
I think the single biggest help would simply be to know what the MC the wood is currently at. Beyond this, as a general rule, I’d recommend starting outdoors and moving indoors after several months — it all depends on what the MC of the wood is at. Tarps aren’t ideal, but yeah, you should try to keep it somewhat protected from the elements — direct sunlight as much as rain.
When large amounts of lumber are to be air-dried, pole-type sheds can be used to achieve greater control over the drying process. Board foot – A unit of measurement for lumber and sawlogs represented by a board 12 inches long, 12 inches wide, and 1 inch thick or the cubic equivalent. Since wood smoke is fuel, we want to burn it as completely as possible and that means mixing with adequate oxygen in the combustion air. Juvenile wood is wood that is formed during a tree’s early years of growth, and can be thought of as an extension of the pith. For most woodworkers, running their own kiln to quickly dry lumber may be impractical or excessive.