It occurred to me after my last post that the next step actually needed to be the assembly of the cans into collector tubes so that they could be curing while I built the frame for the heater box.
In preparation for assembling the tubes, the cans needed to be cleaned up in order to remove the sometimes syrupy residue in some of them, as well as the aluminum "sawdust" clinging to most of them.
To accomplish this washing, I used a clean Rubbermaid heavy-duty trash can on wheels that I happened to have and filled it with water and a pretty good dose of Simple Green concentrated cleaning liquid. After gently (remember they are VERY thin) placing the cans in the liquid, I made sure they were covered with the cleaning solution and "agitated" the whole thing by making use of the fact that the can has the dolly assembly on the bottom.
Cleaning the cans also helps remove any substances that might keep the paint from adhering in a later step.
Attending two funerals this week (niether of them was mine) has slowed progress on the project, but I hope tomorrow to proceed to assemble the cans into tubes once they are dry.