I have just finished a few vases whose wood had sat in my workshop in halves for about two years. Fungi have done some work on the wood so there are some spalted areas. At the ends of the logs there were cracks so I had to cut off about centimetres of wood from each one. The moisture of the wood was 25%.
As the diameters range from 8 to 13 cm, I recommend hollowing the bottom part of the vase to avoid cracks. In addition wood then gets dry faster when the walls are thinner. Later you can put a wooden cone in the hole or a piece of plated metal so that the vase is more stable.
The lengths of the vases range from 40 to 60 cm therefore I had to use the steady rest and drills.
Apart from dry flowers with an insertion from stainless metal they can be also used for live ones.