Hot Air Welders are small light-weight welders that, just as their name implies, use hot air to join materials together. This welding technique is suitable for all of the more common geomembranes including PVC, Urethane, HDPE, Polypropylene and LLDPE. The interface of the two overlapping layers of geomembrane are exposed to heated air that softens their surfaces, which are then pressed together to form a strong bond. Hot-air welders are generally used for detail work or to “tack” materials together in the field.