A machine for making an impermeable join between two panels made of three-layer or two-layer textile material including at least an internal layer, already joined along a joining line by way of a stitching operation, simple or complex, or by ultrasound joining or other, includes first movement element able to move the textile material in a direction of feed and impermeabilization element able to achieve the impermeabilization along said joining line and including second movement element able to move an impermeable tape for hot taping with adhesive, in order to determine the hot application and welding on the internal layer along the joining line. The impermeabilization element also comprise heating element suitable to effect a cauterization of the material of the internal layer and positionable directly upstream of the second movement element in the direction of feed, so that the hot taping can be effected immediately after the cauterization.