The third row of hanging bricks on the nasal part of double “J” type hanging wall at the refining section of the inlet neck of the 500 T float glass furnace fell off, forming a trapezoidal gap which was approximately 4,500 ㎜long, approximately 450 ㎜wide at the lower-mouth, about 250 ㎜ wide at the upper-mouth and about 200 ㎜ thick; the hanging wall was displaced downward seriously and endangered the furnace structure. With the high temperature periscope, the company spent only 4 days in dealing with such a complex case by using the ceramic Welding without affecting the production. Positions soldered were in good operation condition for 25 months in a row.