Aluminum Solder-It ALP-21 flows at 395F far below the melting point of aluminum. It is used to solder many types and gauges of aluminum as well as to solder aluminum to most other metals. It is especially useful for joining dissimilar gauges of aluminum. Use Aluminum Solder-It for aluminum tubing, aluminum antennas, aluminum radiators, air conditioning condensers, refrigeration, aluminum boats, doors, windows, anodized aluminum and aluminum foil. Great for constructing and repairing Remote Controlled Aircraft Parts and cosmetic repair of Homebuilt Aircraft/Parts.