This technology dates back to pre-Roman times and was widespread in the medieval period.
Tinning of iron refers to the coating of iron with tin or tin alloys (normally with lead). This enhances the appearance, improves the protection against corrosion and permits soldering with lead solder.
Different methods of manufacture
1. Hot dipping - Heat tin with flux (tallow or resin) to 260 C that dip in the clean, degreased, oxide free sueface of the iron or steel sheet that had been pickled in acid. Gives a 10-20 micron coating.
2. Wipe tinning - Applying solid tin to the oxide free surface of iron coated in flux that is then heated. Used for large pieces.
There are other techniques.