3. Electrolytic tinning

3.1 General

Once the strip has been prepared by degreasing and pickling, it is cathodized in a Sn(II) stannous tin solution. Tin baths based on stannous tin, Sn(IV), are no longer used, as their higher operating cost compared with stannous baths was not justified. Ion discharge leads to the following Sn tin metal:

In addition to these stannous ions, the bath contains an acid to lower the pH and increase electrical conductivity, and an additive to increase operating flexibility. This notion, dear to the practitioner, actually covers the surface area of the temperature-current density diagram where the deposits formed are covering: outside this...