Tin Cans
Unlike glass jars, tin cans are used only one-time. Canning in tin was favored primarily by those working in bulk due to cost-efficiency. Additionally, cans could be stacked when processing, if space permitted, were less prone to breakage if transported, and could be rapidly cooled by placing in cold water directly after processing.
Home canning tins could be purchased lined or unlined.
’Sanitary enamel’, or ‘R enamel’ or ‘fruit enamel’, cans are of deep gold color with bright finish. They are used to prevent fading of color in red fruits and certain red vegetables, and to prevent corrosion with pumpkin and squash.
‘C enamel’ cans should not be used with acid foods like fruits, tomatoes, or sauerkraut, nor with meats or other products when these contain much fat. Acid or fat may cause ‘C enamel’ to feel off and make the product unsightly.
--United States Bureau of Home Economics. (1935). Uses of enameled tin cans. United States Bureau of Home Economics. Retrieved from https://archive.org/details/CAT31039160
Early tin cans were sealed through the cap-and-hole process.
When the can has been filled…clean and wipe the groove around the opening, put the can into place, and solder…
--United States Department of Agriculture. (1921). Home canning of fruits and vegetables. Farmers' Bulletin, 1211. Retrieved from https://archive.org/details/CAT87202920
[A]pply the capping steel, holding the cap in place with the center rod while lowering the steel, and turn it steadily back and forth until the solder flows. Do not bear down on the capping steel.
--United States Department of Agriculture. (1921). Home canning of fruits and vegetables. Farmers' Bulletin, 1211. Retrieved from https://archive.org/details/CAT87202920
Immediately after exhausting, close the small hole in the top of the can.
--United States Department of Agriculture. (1921). Home canning of fruits and vegetables. Farmers' Bulletin, 1211. Retrieved from https://archive.org/details/CAT87202920
While there was overlap in their use, mechanized tin can sealers came to replace the cap-and-hole process. Sealing sanity or rim-seal cans required a hand operated canning machine that locked the cap in place and created a hermetic seal through a tight double seam.
Two distinct operations are required to seal the sanitary or rim-seal cans. Put the lid on the can and clamp it in the machine (fig. 12). Apply the first roll gradually while the can is revolved. This operation should be continued until the cover is locked into position all the way around and the lap joint is made. The second roll is then applied and the can resolved to close the joint and thus hermetically seal the can.
--United States Department of Agriculture. (1921). Home canning of fruits and vegetables. Farmers' Bulletin, 1211, 33. Retrieved from https://archive.org/details/CAT87202920
The current USDA Complete Guide to Home Canning does not include guidelines for the use of tin cans.