Not sure its oak. From the coloring in the cut, and the amount of sap wood, it looks more like sweet gum to me. I would seal all exposed raw wood instead of just the ends.
With all the color variation, sweet gum makes some attractive items, especially turnings (in my opinion, anyway). Due to all the cross-linked grain, its a little difficult to work with, and really tough to dry into flat boards. It is also very difficult (right on the edge of impossible) to split straight with a froe, etc. If you try to split down a corner of the cut and it won't cleave off nicely, its more likely sweet gum.
I do use it for some "furniture" type work, but have mostly used it for biscuit trays, etc. Unlike red oak, though, it does make a water tight bowl.
JMTCW
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