Dear Ed,
I am no expert, however I have canvassed several canoes. The answer is for the first steps of canvassing--right side up; then for the last steps, turn the boat over. I followed the procedure outlined in the book The Wood and Canvas Canoe, A Complete Guide to its Construction, Restoration, and Maintenance, by Stelmok and Thurlow. These expert builders suggest: canoe right-side up--canvas suspended with wooden clamps---well anchored at one end---come-along winch at the other. Some sort of heavy 'ballast' in the boat. Then once you achieve the proper tension on canvas, attach canvas at each rib with help of artist's canvas pliers. Then to do the lap joint at the ends---turn the boat over on saw-horses and work along the stem toward each end of the boat. If you don't have the book I am refering to, purchase it. Read the section on canvassing. I followed those guidelines each time, there are many details I omitted in my email worth learning from the book, then procede. I did this and ended up with fine results each time. ---Sam