Rusting: dent on tin cans

bonkysleuth SG

My teacher said that if we ever see a dent on tin cans, we should avoid buying the product because the inner surfaces could be rusty. Could someone tell me why when the iron surfaces rust, there will be a dent? Because the iron has reacted away?

dkcx SG

All cans are coated with a later of Al (or some other metal i 4got).

The dents are not cause by the rusting. The reason for him/her saying that is that when a can is dented due to physical damage, there are chances that the coating might be affected and this might expose the unprotected metal which will rust and thus poison the food it contains.

Darkness_hacker99 SG

I read about this at here

http://nicholasacademy.com/scienceexperiment288nodentedcans.html

Kuali Baba SG

When the can is physically dented, it is no longer sealed and microbes from the outside can enter. It also deforms the tin coating which protects the aluminium underneath.

dkcx SG

When the can is physically dented, it is no longer sealed and microbes from the outside can enter. It also deforms the tin coating which protects the aluminium underneath.

Its tin coated Al cans ah... Paisei totally forgot what those cans were made of...

fudgester SG

All cans are coated with a later of Al (or some other metal i 4got).

No. They are coated with tin.

When the can is dented, there is a chance that the tin layer may be get damaged, exposing the steel (not aluminium) underneath to the ambient air.

The problem is that air-exposed steel rusts even more rapidly when it is in contact with a less-reactive metal like tin than when the steel is on its own.

So if the tin can is dented or otherwise damaged in any way, it is best to avoid buying it.