: . . . In an earlier thread a couple months ago,
: someone (Paul Jacobson? was that your idea?) described how to make a
: removable bulkhead that is a smaller plywood core sandwiched between two
: larger diameter pieces of foam with a handle protruding from the middle of
: it, sized so that it will fit snugly into place like a plug.

Actually, it was the other way 'round.: A couple of pieces of plywood sandwiched around a single thick piece of foam. When the bolts holding the plywood together are tightened the foam is forced out at the sides a bit--putting some pressure on the hull to hold the thing in place. Cutting the pieces to a close fit helps the thing work like a plug.

PGJ