XXX Best Glue for Metal Models - Painting and Modelling - The Grand Alliance Community Photos
The first is good old CA. It's excellent for holding things together Modelss long as there aren't any shearing forces being applied. The second is Gator's Grip acrylic glue.
However, as there are different types of metals, also many types of metal bonding adhesive are available including machinery and structural adhesives.
They all melt the plastic, creating a super strong bond between the plastic pieces. The difference lies in how the glue handles.