Polyisocyanurate foam should not be cut with hot wire tools. It needs a ton of heat, gives off toxic fumes, and leaves a lot of melted plastic wherever it is cut. We recommend that the polyisocyanurate foams only be cut with a blade or saw. | Polyisocyanurate foam should not be cut with hot wire tools. It needs a ton of heat, gives off toxic fumes, and leaves a lot of melted plastic wherever it is cut. We recommend that the polyisocyanurate foams only be cut with a blade or saw. |