Abstract: An automatic seam welder for thermoplastic material includes a single piece frame riding on two drive wheels and a caster, the drive wheels being driven by a drive motor through a helical spring clutch. A heat gun is gimbal mounted to the frame and includes a blower, heating element, and shaped foot to direct hot air between overlapped thermoplastic sheets. A thermocouple in the foot directly senses the air temperature and, through a control circuit in a control instrument enclosure, is used to control power to the heater element. A guide wheel, foot rest and air dam are also provided.

Abstract: A recirculating sandblasting device having a generally cylindrical body with a conical blasting medium bin is mounted on a cart and includes a cyclonic separator and a high capacity filter for filtering air drawn in by a blower and motor within a motor housing. A sandblasting head includes a supply line to draw blasting medium from the medium bin and a return nozzle with a resilient bellows connected to a recovery hose for returning laden air to the cyclonic separator in the body.