What is condensation in finished glass?
This phenomenon, also known as weathering or fogging, is created in Type 1 glass when heat causes water-soluble alkali salts to vaporize. Some of these salts condense on the cooler portions of the inner surface, leaving a white or gray film that looks like smoke. During transit and storage, the glass surface is exposed to moisture, which may cause the salt film to dissolves and form crystals. This phenomenon is normal and does not indicate a contaminate condition. The salt may be completely removed by rinsing with water. As flint/soda lime glass is exposed to the atmosphere, a complex reaction occurs on the surface between the alkali on the glass and gases in the air. These reactions are commonly known as weathering. Weathering is a normal condition and the quantity and appearance vary depending upon the amount of time, humidity and temperature of storage. Keeping the glass under a constant low humidity is the most effective method to slow weathering as it keeps the surface dry. Period
