I am a newbie when it comes to turning. I bought my first lathe in March or April of this year. It is a Delta 46-715 type 1 (the 14" one), but the person I bought it from took VERY good care of it and had some work done on it.
As for turning the goblets, I have made two. . . uh . . .prototypes (yeah, that's it!) before I started this one so I could come up with a design that I liked. the first one came out ok, but I didn't like the design or proportions. The second one came out much better and except for the wall thickness of the vessel would have been good. I did some of the hollowing in less that adequate light and there was one part where the wall thickness got too thin. It was so thin that when I put some polyurethane in the vessel part, some of it actually ran out the side. Guess I need to work on my lighting (Not to mention technique).
So about that wall thickness, I'm sure a lot depends on the wood, size of goblet, design, etc. My goblets are going to be about 9" tall and the vessel part will be about 3 1/2 inches deep and a little over 3 inches in diameter. The wood is Spanish Alder which is a very light wood (both in color and weight), and is very open grained so I'm thinking that about 1/8 inch should be good, and then sand it so that it tapers a little thinner at the rim. Sound about right?
My second question, I am making these goblets as a gift and they will probably be mostly decorative, so I don't think they will get used very much. But they might get some use. What would be a good finish? Is polyurethane good (and tasteless)? Would epoxy be better? Or . . .???
TIA,
Wayne