Overcoating a furnace is one of the most intricate and demanding tasks in furnace maintenance, requiring a high level of skill and precision. As furnaces age, particularly in the later stages of their life cycle, the top portions of AZS sidewall blocks begin to corrode due to continuous exposure to molten glass and high temperatures. This corrosion weakens the refractory material, posing risks such as glass leakage and increased energy losses. 

Hot overcoating addresses these issues by reinforcing the furnace’s structure. The process involves removing the support refractories from the AZS sidewall blocks and replacing them with AZS tiles. These tiles, typically ranging in thickness from 75mm to 125mm, are pre-heated to over 900°C in an external kiln. The heated tile is then installed directly onto the furnace’s sidewall block while still at this high temperature, ensuring a seamless fit. 

Although overcoating is highly effective, it is far more complex than it seems. The extreme heat, combined with the precision required to install the hot tiles, makes the process both physically and technically challenging