I was looking at the 1972 Chestnut catalog, and this is how they describe their construction process: Light cedar planking and ribs (with brass fastenings) comprise the shell, over which is stretched heavy-duty seamless canvas. The canoe is then treated with a Chestnut-formulated iron-hard coating developed over 75 years, to withstand ageing and abuse. The entire unit is then baked for a two-week period. This unique construction ensures many years of extended service not found in other makes. Does this mean they heated the canoes to speed up the filler curing process? Has anyone else tried that, or know what temperature they might have used?