Here is a a bit of "hands-on" high-tech methodology used to prepare the pop cans. I stick with one type in order to insure uniformity and join the cans bottom to bottom and top to top.

Hands-on because I grind the bottom of the can off by holding the can down against sandpaper on a table top, and sand it with a twisting motion. I try to avoid sliding the can because that could lead to uneven abrasion. Granted, after a few cans, I sensed my perfectionist attitudes were being ground away as well. Wear a heavy leather glove if you plan to grind more that a couple cans.

The can on the right shows the results of the bottom being sanded away. I start with 60 grit, then 100 and a final smoothing with a 220 grit. If you wash the cans out, the remaining water will seep out as you get close to finishing and muck up your sandpaper, so before sanding, toss a piece of paper towel into the can and wipe it around with a screw driver. Like trying to not bite into a tootsie-pop, you'll probably not sand until the bottom drops off. Instead you will notice the beginnings of the separation and with a thumb nail, just complete the task. I give an extra couple swipes with the 220 grit to eliminate any burrs that remain.

The top is cut out using a Dremel. I made a wood stand for the Dremel so I could hold the can with two hands. That makes the job much easier.

I set the cans against something to help them stay aligned and used the block on the right to help keep them together. Obviously the contact is quite good throughout. After smearing the adhesive around the joint, it sets pretty fast and can be stood on end to dry.

The picture above was similar to the cans I used in my collector but because the two cans were about 1/16-inch too long to fit in the jar, I cut off one end (hot air intake side) just below the seam. Then I painted the cans with some old flat black oil based heat-resistant paint that I found on a shelf...hiding. I suspect I'll get a fresh can of the spray variety when repairing my "melted" components as the paint was still tacky after 15 hours and was not very "flat".

When installing the cans, I had a momentary lapse of judgement and had to unbolt and remove them from the, jar lid, which was already attached to the base.  During the removal process I saw just how weak in tension this adhesive was and the cans pulled apart. I stuck them together and with it's tackiness, almost seemed adequate. But for good measure I added duct tape! One of the universal corrective materials that should always be on hand.

I indicate that this component "melted". The duct tape did have issues with being subjected to 250-degree F plus temperatures. I know just grabbing the thermometer that was measuring the internal temperatures that if I were in there, I would also have melted.

My next project will most likely use six rows of 7 cans each, and be roughly 3-feet-long, so this technique for cutting the cans will be used extensively. I will have to discover a better, heat resistant adhesive and devise a more structural means of support for that system. I simply hate when my cans droop and fall apart.