A mobile thermoplastic applicator comprises a kettle, a main gas burner, a heat exchanger plenum, and a screed die box. The kettle has walls which define an interior space for melting thermoplastic. The main gas burner is situated beneath the kettle, and is configured to heat the kettle. The heat exchanger plenum is situated inside the thermoplastic kettle and is configured to subdivide the interior space and circulate heated air from the main gas burner. The screed die box is configured to receive molten thermoplastic from the kettle and deposit that molten thermoplastic on a surface.
