Heat sealing

Heat sealing is a finishing technique where a heat source is briefly passed over EVA foam to close its pores, creating a smoother surface that accepts paint and sealant more evenly.

When you work with EVA foam, the cut or sanded surface is covered in tiny open pores that can soak up paint unevenly and make a finished piece look rough or blotchy. Passing a heat gun quickly over the surface causes those pores to close up and the outer layer to tighten slightly, giving you a denser, smoother base to prime and paint. Use a heat gun, never an open flame such as a lighter or torch. Keep the heat gun moving, work in a well-ventilated area away from anything flammable, and avoid breathing the fumes from warmed foam. The foam stays hot for a short while afterwards, so wear heat-resistant gloves, never leave the tool unattended, and make sure younger makers have close adult supervision. Check your heat gun's own instructions for safe use.