Weathering of Glass

Weathering of Glass

Weathering of glass is a form of glass corrosion that causes discoloration of glass. Archaeological glass shows weathering, but contemporary, historical and modern glass also show it at some level.

Weathering of glass consists of soluble crystals of salt (sodium carbonate) and an insoluble film. The addition of carbonate, dirt, moisture, and organic material is found on the weathered glass as compared to the original glass which basically consists of lime, silica and soda. The thickness of weathering depends on how stable the glass can be under different conditions.

Solubility plays an important role in weathering of glass. The glass shows similar resistance to weathering and water under temperature and pressure above the normal limit. Resistance of glass to weathering is increased by alumina whereas the existence of sodium carbonate after manufacturing increases the chances of weathering of glass.

Specimens can be exposed in climate chambers with varying time periods and under varying relative humidity. Effects of weatherization can also be reduced by bloom treatment in which glass is treated with fluorine gas to make it ten times more chemically inert. 

Video 01: Weathering of glass

Common Uses of Weathering of Glass:

• For solar application

Advantages of Weathering of Glass

• Weathering preserves the original surface unlike metals as the corrosion in glass occurs from the outer to the inner surface.

Limitations of Weathering of Glass

• More susceptible to fractures and cracks
• Glass may break in some cases which may prove fatal.