The copper solders which are used for soldering copper as well as bronze are mixtures of copper and lead. By increasing the quantity of lead the fusibility is increased, but the mixture departs from the color and toughness of copper. The most commonly employed copper solder is the following:

I

Copper........... 5 parts

Lead............ 1 part

II

Copper........... 80 parts

Lead............ 15 parts

Tin.............. 5 parts

For Red Copper

I

Copper, 3 parts; zinc, 1 part.

II

Copper, 7 parts; zinc, 3 parts; tin, 2 parts.