This is a wood lathe, made by Delta/Rockwell, that I am working on repairing (you'll hear more about it in the future!) It had sat outside in the elements for about a year, and I'm working to de-rust and repaint the lathe. One day, I'll be able to use it. Hopefully.
Anyway, back to the topic at hand.
When you cut down a tree, the wood can be turned directly on a wood lathe. This is known as turning "green wood", and it's not something that is generally recommended for the beginner. It's messy, it's slippery, and the piece will warp as it dries.
Instead, most wood is dried- in kilns, chemically, or in the air- until it is dry enough that it will not warp very much. Then, it can be used in projects, in construction, or any other purpose, including woodturning. Air drying for some large lumber pieces can take years. This is why the more costly kiln method is used- it's fast.
In my front yard, I removed two staghorn sumac trees (Rhus typhina) because they were knocked over by heavy weather.
I wondered to myself if I could use some of the wood for woodturning in the future. Apparently, according to several online sources, sumac is just fine for woodworking.
I kept three logs from the trees. After washing each off with warm water (to get any dirt off), I was ready to start.
Checking, or cracking of wood along the grain, can be caused by uneven drying of a piece of wood. By sealing the porous ends of the piece of wood, water can evaporate at a controlled, slow rate from a piece of lumber, causing checks not to form.
Popular ways of combating this for air-drying lumber include dipping the ends of the wood in paraffin wax, painting the ends with latex paint, and using chemical sealants. The fact that I had extra latex paint from wall painting helped me decide that it would be the best option for me.
I went with off-white latex paint. The color really doesn't matter; it won't be seen on the piece of lumber when you are done.
Make sure that you stir the paint thoroughly.