One of the shop areas near the Canadian Canoe Museum in Peterborough Canada had canoes under construction. Here on a wall were stored canoes being built on forms. There were several heavy forms here made of wood with heavy metal strappings. The ribs are steamed and bent over these forms and then planking tacked on and through the ribs. When the tack goes through the rib it hits the metal band and turns back on itself and can be clenched to a tight fit.