How long will a tin can last before degrade?

Question

How long will a tin can last before degrade?

Answer 1

a lot longer than it would take you

Answer 2

Do you really mean a "tin can" made of tin or a modern steel can that we just call a "tin can"?   Some actual tin cans that were used in the arctic and antarctic expeditions in the 19th century still contained food that had not spoiled.  Surely some of that is due to the extremely low temperature.

Modern "tin cans" are steel coated in paint and enamel, often with a plastic liner.  This pretty much isolates the steel from the environment that would allow it last for many years before rusting away.

Answer 3

If you mean how long will it last when it is burried in the ground? That will depend greatly on the wetness and acidity of the soil and what it is burried with.

I dig up antique bottles as a hobby and have seen cans and other iron objects burried for varying lengths of time. In our area, the northeastern US, the soil is quite wet and usually the largest component of the average old dump is coal ashes and clinkers so the soil tends to be pretty corrosive, even glass  bottles can be heavily etched!. Cans burried in about 1920, typically had the modern type roll crimped lid & bottoms and could be dug out with care but were total rust in the shape of a can. Occasionally small amounts of metal remained but this was the exception not the rule. Cans burried in the victorian era, with the flat seam soldered tops & bottoms, say about 1870 to 1890 or so, were totally rust except for the little ring of solder where they were originally sealed, and sometimes the solder of the edge seams. I never dug intact cans from dumps of this era (even if all rust), but most old dumps were thrown down hillsides where I live and the strata settle and shift over the decades so that might explain finding only crushed bits. Cans that happened to contain paint, grease, lard etc seemed to be in better shape due to those materials inhibiting water getting at the metal. Where we live, the soil is so wet, even chunkier metal objects like cast iron toys, tools, coffee grinders, horseshoes etc are often rust to the core after about 100 years of burrial (unfortunately).

So, I would say in damp, moderately acidic soil, cans would last less than 100 years.