Material pair

Metal to Plastic

Best bet

Wets out both surfaces. Scuff smooth plastic first so the glue can grab.

Preparation

Prep each side differently

Scuff and degrease the metal.

Scuff the plastic too — shiny molded surfaces shed glue. Check for PP/PE, which resists epoxy.

Conditions

If the plastic flexes in use, a flexible adhesive beats rigid epoxy. Small, tight-fitting parts can use super glue gel instead.