Aluminum and steel transition joints are used wherever these two metals need to be welded together. The transition joint is made by explosive welding. Conventional welding is used to weld steel to the steel side and aluminum to the aluminum site to produce the end product, such as a ship's superstructure. Provided the weld area is sufficiently distant from the bond interface so that heat induced intermetallics are not formed, the bond will not be compromised. With explosive welding, it is easy to weld aluminum to steel. Sigmabond's process makes it even easier by doing away with the wavy interface and creating a stronger bond.