Adhesive Types
A guide to common adhesives used in model making
Structural
Polyurethane Adhesive
Moisture-activated adhesive. Expands as it cures, excellent gap-filling. Clamp 1–2 hours; full cure ~24 hours. Bonds virtually all materials. Not suitable for fine or precision work — expansion is hard to control.
A moisture-activated adhesive that foams and expands as it cures. You dampen one surface, apply the glue to the other, then clamp firmly. The expansion means it fills gaps well, but it also means unclamped joints will foam apart. Full cure takes around 24 hours. Commonly sold under brand names like Gorilla Glue.
Polyurethane adhesive bonds an unusually wide range of materials, including many that other adhesives struggle with — foam, stone, ceramic, and dissimilar materials. In model making, it’s useful for bonding expanded polystyrene and extruded polystyrene where solvent-based adhesives can’t be used, and for rough-fitting joints where gap-filling matters. The expanding foam can be messy and difficult to control on fine work, so it’s best suited to larger-scale construction and terrain building. Once cured, the excess foam can be cut and sanded.