The next step is to remove all of the bark. This can be done using a tool called a bark spud. (Available at woodworking suppliers for around $45) Removing the bark allows the moisture to escape from the logs more evenly through the surface not just at the end grain.
Next seal the end grain of the logs with log end sealer or you could use a less expensive alternative called roof patch sealer. I have found there’s not much difference between the more expensive lumber / log end sealers and the inexpensive roof patch sealer. The sealer acts like a barrier so the moisture can escape through the log surface rather than the end grain. If you don’t coat the end grain of your logs, the moisture will travel along the inside grain of your logs producing far more cracks in your logs. Depending on the species of tree these cracks can be quite long. You can save up to 10% of your lumber value by sealing the ends of the log.
Stacking Your Lumber
Be sure to find a place as flat as possible to stack your lumber. Avoid damp or boggy areas. If the ground seams damp, place a vapour barrier on the ground where you’re going to stack your lumber but also provide a slight drainage
Pick a spot in a shaded area rather than direct sun for your stack. The sun causes the wood to dry too quickly causing severe checking and warping. Ideally your stack should be in an area where prevailing winds can blow through the stack, not through the ends but ideally through the sides. It’ll dry much quicker and your lumber will not crack as badly.
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 good indicator of how well your lumber is drying is to see if there is any evidence of mould on the wood. Mould is an indicator that there is poor air flow through your stack. If the mould is severe enough it can cause your lumber to stain or begin to rot. To stop the mould you will have to wipe down each board with a solution of bleach and water, and then relocate your stack to an area with better air flow and ventilation.
The lumber stack should be at least 1ft to 2ft off the ground. You can make a base for the stack out of old railroad ties, concrete blocks, and 4 ”X 4” s or anything that is square. (See drawing below) The base MUST be level and even with each other, the flatter you get it, the straighter the lumber. If the base is not even, the lumber will dry with the contour of the base.
Lay down 3 separate support pieces the length of the longest lumber you are going to cut. These main supports should be separated about 3 feet apart. Across the main supports lay more supports at 2 foot spacing and this is what your lumber is going to be placed on. Once this is done just make sure the cross supports are all even with each other. Now you are ready to stack your lumber.
You should have lots of “sticker sticks” handy. These are just 1”x 1” or 2”x2” dry lumber sticks. Lay a first row of stickers on top of the cross supports 2ft. apart. Then lay a course of lumber on these sticks. Laying stickers across the top of this course of lumber ensures that the next piece of lumber is separated by a 1” gap. Make sure each sticker is aligned with the previous stickers so there is even support throughout the pile.
The 1” gap aids in rapid air drying. See drawing below.
You can stack your lumber as high as you feel comfortable with. I find that 5ft to 6ft is about as high as I go unless I have help. The stack can also be as wide as your base supports. Once you get to the top of the stack, lay thicker stickers across the last lumber course. The next step is to cover your stack of lumber with tin-roofing or plywood then weight the cover down with concrete blocks, old steel, or anything that has weight to it.
Try to get the weight to sit on top of the last stickers underneath. This will prevent the top layers of lumber from warping. You should also ensure the top cover has long overhangs for your stack. The longer the overhang the better. (Minimum 16” overhangs) Remember, you want to have good air flow through your stack. Covering your lumber with a tarp does not allow any air flow and will cause mould and rot to start.
If the over hang is too small you can lay plywood over the ends of the lumber. just make sure you leave enough space for air flow. The plywood leaning on the ends of your stack will prevent the rain and sun from getting in direct contact with the end grain of your lumber. Direct-sun on the end grain of your lumber draws out the moisture too quickly causing it to dry out to quickly creating severe checking, warping etc. You may loose over 10% of the value of your lumber if you don’t follow this step.
The next step is to slow down the drying process in the end grain of your lumber. Coat the ends of the lumber with log end sealer or less expensive roof patch. In my experience, I often coat the ends of my lumber before I stack especially if I’m working with various lengths and have to stack them butt to butt.
Air Drying Your Lumber
Inside a garage or barn the drying process can take three or four months or longer before the wood reaches 20%-15% moisture content but your lumber is subjected to the risk of mould and rot due to lack of air flow and ventilation.
If you’re intending to use your lumber for furniture or cabinets, then you need to get the moisture content below 9%. Too be able to get your lumber to 9% or less moisture content you must bring your lumber into a warm environment (usually your house) once your wood has reached the 20%-15% range or less.
Ideally you want to stack your wood in an area where it will be used. Bringing your lumber into a warm environment before the moisture content reaches 20%-15% will cause your lumber to severely check and warp due to rapid moisture loss.
The way to check moisture in your lumber is with a moisture meter. A moisture meter (about $100 at woodworking suppliers) is the most reliable means of determining moisture content. Check the wood every few weeks outdoors and more frequently after moving it indoors.
The cost of air drying your lumber is minimal and the rewards will speak for themselves once you begin to work with your wood. There is an endless supply of unique species of wood available which will never be available in a lumber yard. Also because we are using a resource which would be normally considered waste, we are reducing our footprint on our environment.
|© 2008 Mike Bjelos, Enviro Tree Milling|