28 March 2017

Difference between galvanizing and tinning

Galvanizing is an iron or steel sheet coating process with a thin zinc coat to avoid rusting. Tinning is a coating tin over parts of iron or steel. Both the coating method is used to avoid corrosion. Let us have a deep insight into the difference between galvanizing and tinning. 

Galvanizing :

  • Zinc is used for coating.
  • Since this method is more electropositive than iron, zinc sacrificially protects the iron and does not allow the iron to pass into the outside solution.
  • Zinc continues to protect the underlying iron through galvanic cell action in the galvanized article, even if the zinc layer is punctured or broken somewhere.
  • Galvanized containers can not be used to store acidic foods as zinc reacts with extremely toxic zinc-forming food acids.

Tinning :

  • Tin is used for coating.
  • Due to its noble nature and higher corrosion resistance, Tin protects the base metal, iron from corrosion.
  • Tin is non-toxic and protects the iron at the base until the coating is perfect. Any coating break creates fast iron corrosion.
  • Tin-coated containers can be used to store any food as tin is non-toxic, protecting the metal from corrosion, and preventing food poisoning.