A manual or semiautomatic process used to weld polymeric composites. A heated gas is blown over a welding rod and the joint surfaces. The molten rod is used to fill in the joint and weld the two parts. Hot-gas welding is suitable for small weld areas, but is
slow even for small areas, with welding rates of 0.8 to 5 mds (2 to 12 in./min).
Hot gas welding is used primarily for low-cost composite matrices with lower melting temperatures for small-volume production of parts with many varying geometries. Hot gas welded joints cannot be used in high-strength applications because the joint area is small (on the order of the part thickness) and it cannot compensate for discontinuity in the reinforcement across the joint.
