THE WELDING TRUCK WAS BROUGHT TO THE SHOP AREA AND PARKED. THE MAINTENENACE CREW WENT TO THE WATER PUMPS AND DRAINED FOR THE NIGHT. UPON RETURNING TO THE SHOP AREA EE ROUNDED THE CORNER OF THE BLDG AND DISCOVERED THE WELDING TRUCK WAS ON FIRE. THE CREW TRIED TO PUT THE FIRE OUT WHILE SUMMONING THE STRINGTOWN FIRE DEPT. ALL FLAMES WERE OUT WITHIN 25 MINUTES OF STARTING. FIRE BURNT