I had mounted the blank on to a ply wood face plate glued with PVA to turn the bottom underside and create the tenon mount a coat of Danish Oil.
Reverse mounted roughed down
This is the largest I have turned to date all went well not even a dig in.
Now onto the supports and finial etc.
Mondy March 26th an update of photo's.
First photo is the 14" and 18" together, the other two photos are the 18" showing the grain/pattern. The centre holes yet to be drilled to size when I have completed the supports which I am making at the moment.