I would not classify two bowls glued together as a "hollow form". I
think of them more as an attempt at salvaging a matching pair of bowls
after accidentally going through the bottom of one.

(Just my sarcastic bent of the day, recuperating from a wisdom tooth
extraction two hours ago...)
David

Derek Andrews wrote:
"If it cannot be made with a conventional straight gouge or scraper".



And what about those 'hollow forms' that are made in two pieces, top and
bottom, then glued together?