Recently I attended the Yeehaw Junction Bluegrass Festival about 30 miles west of Vero Beach, Fl. An instrument builder there, Ken Bailey, had an all-aluminum banjo (see attachment) he had built with a friend who had a machine/weld shop. The neck was a “T” cross-section and fret markers were screws. Sounded a little tinny but not as much as you might think. It was actually lighter than the Williams I play which weighs ~11 pounds.