Hello ladies and gentlemen. I'm wondering what domestic hardwoods can be kiln dried together reasonably safely from GREEN? Can't seem to find a chart on that. I know there are many that can be kiln dried safely together once air dried. I expect the list and groups will get significantly smaller for green. We deal mostly with cherry, red oak, black walnut, hard and soft maple, chestnut oak, and occasionally white oak (in a class by itself). Thank you in advance for any help.
BK
If you go to the kiln schedules in Drying Hardwood Lumber, Tables 7.11 through 7.21, you will see the species that we grouped together. Ok?
Hello,
It is my perception that for kiln drying it is always recommended that you do not mix species. If you do though, make sure your sticker placement is even as you look down the stack top to bottom. Also, ensure your chimney is even as it goes up, and somewhat closed at the top. Try and kiln dry units that are all even in length, and boards that are equal in dimension. IE do not leave boards sticking out on the ends, and do not mix 4x4 and 2x4. Air circulation is the key with a kiln. It MUST be even. Uneven circulation will encourage uneven drying, and warping. There is a science to the schedules, and it has been exacted by very intelligent people. Also, remember that lumber expands differently in its tangentials and radials as related to the grain. Different types of sawing will produce different grain structures in the lumber and therefore different drying habits and different kiln schedules.
Hope this helps at least a little :)
Like Gene says, if the drying schedules are similar, then you should be able to mix species.
But some need to be dried slow (to prevent checking etc) while others need to be dried faster (to reduce staining). Mixing those is likely going to cause a problem, because one is going to be on the wrong schedule.