The small back arch of the float glass furnace is often corroded by alkaline atmospheres and local temperature changes within the furnace. The entire ring of arch bricks in the small back arch has fallen off, and the side walls of the small furnace below the small back arch have collapsed, creating a defect approximately 500 mm wide and 2000 mm long, with serious fire penetration. Further erosion could lead to the collapse of the small back arch, posing a threat to the structural safety of the furnace.Our company's high-temperature ceramic welding repair technology, combined with a high-temperature induction ceramic welding gun, successfully repaired the furnace defects and extended the furnace's service life by two years.