Lead-Free Acid Core Solder 1 oz. tubes are 1/16 In. in diameter, with a melting temperature of 460 degrees Fahrenheit, Dorman's Solder provides a fast, simple and inexpensive way to permanently join electrical wires and metal parts. Our water-soluble Acid Core Solder, for non-electrical applications, is ideal for fitting connections and sheet metal joints. It is recommended for use with galvanized steel, brass, nickel copper, and many other metals. Dorman's Rosin Core Solder should be used for electrical work.