Comments

1. 
   divertom | Mar 18, 2023 03:36pm | #1

   A good video on drying lumber which I hadn't seen before. I'd like to pass along my solution I came up with to use in the high desert of eastern Oregon. When I began milling lumber after a big fire here, I quickly realized I needed to dry it better than just air dry. I looked at several kiln designs I could make before running into an article which mentioned using a greenhouse. I already owned two which were 12x24 and I hadn't set up yet after moving from California.

   I poured a concrete slab after placing plastic underneath to prevent moisture migration and set up a greenhouse with doors on both ends where the prevailing wind can blow thru it. I get a lot of good hardwood from tree trimmers in town, along with pine and fir logs from the mountains around me. I do much the same as explained in the video: I coat log ends right away to limit checking and have the board ends already sealed before they go in the kiln.

   My boards normally go straight from the mill to the kiln and are stickered as they go in. With green wood, I leave the doors open perhaps a week, plus may add a fan, if the wind isn't blowing enough. Once the wood gets rid of enough surface moisture, I can start closing the doors. The sun manages to heat it to between 120-140 during the day while it cools down to 50-70 at night, before doing it again the next day. Usually, there is enough air leakage to get rid of the moisture, if not, I can open the doors a bit. This has proved very good at slowly drying the wood to 8-10% while limiting cupping and warp even on notorious species like our Siberian Elm here. I'm not spending any money heating the kiln, yet also get it hot enough to kill off the boring insects which are otherwise still alive in air-dried lumber a year or two later. This has proved both low cost to build and operate for me.