A metal joiner is a skilled tradesperson who specializes in joining metal components together. They use a variety of techniques, such as riveting, soldering, and arc welding. Riveting involves using a tool to drive a metal pin through two pieces of metal, creating a strong bond. Soldering is a process of melting a metal alloy to join two pieces of metal together. Arc welding is a process of joining two pieces of metal together by using an electric current to create an arc between the two pieces.