To protect Tundish permanent layer from corrosion, a primer mass layer with 30 mm of thickness will trowelling on it, this stage name is sacrificial or work layer. It is important that the liner is in direct contact with the molten steel. The main task of this layer, is removing the remaining liquid, without damage the permanent layer. The liner also has the task of preventing heat loss when transferring the liquid molten steel to the casting line responsible. That is why the mass should be low heat transfer.