Hey that's pretty neat.
I don't think tin cans are galvanized but the are aluminum. I use these cans in making a cold smoke generator for cold smoking foods. I would suggest that you heat the can up to over 400* F to burn off all the coatings that are used in "tin" cans. I put them on the gas range with the hood turned up high and the noxous fumes that burn off are pretty nasty but once the coatings are burned off there are no more fumes given off.