I have slabs made from a tree we cut down. You need to let the wood age so certain chemicals wood gives off when it dies are no longer present. And you will want to remove bark as it molds easily and hides pests from sight. I spray my mounts with antifungal on a regular basis as they can get moldy and a mess quickly. The dendrobium I posted today has a chunk of that wood we cut in the middle of the larger pot it is sitting in. So far both the epidendrum and dendrobium seem very happy.