Of course, the gasket in the lid also is burned up in the process. The lid was held in place by using about 6 of the securing tabs. The 5 gal can was placed on the grate and the 32 gal lid was used as a damper and to help hold the heat in. More wood was loaded into the fire. After about 45 min the grape starts breaking down, in the absense of oxygen, and the steam and flammable gases began to escape from the vent holes in the bottom of the can.
Flames are also present around the lid.
The 5 gal can was removed, cooled down and then opened. Perfect, black, hard grapevine sticks. These crush much easier than mesquite. I weighed 3632 g of grapevine which yielded 709 g of charcoal in one 5 gal bucket. After 5 loads I ended up with a 5 gal can of moderately crushed grapevine charcoal.