An improved method for mending a dent formed on a smooth outer surface of a member made of aluminum or an aluminum alloy. A solder plating layer is effected on the surface of the dent using a low-temperature solder for aluminum. Then, a solder plating is effected on the plating layer using a low-temperature solder. Subsquently, build up soldering is carried out on the plated surface of the dent to be mended using a high-temperature solder. Preferably, the surface of the build-up high-temperature solder layer is ground and polished, and then the ground surface is subjected to a finishing treatment using putty.