coppering

/K AA1 P ER0 IH0 NG/
verb
  1. 1

    To sheathe or coat with copper.

noun
  1. 1

    The act of covering with copper.

  2. 2

    An envelope or covering of copper.

Source: https://en.wiktionary.org/wiki/copper, https://en.wiktionary.org/wiki/coppering