Damage to glass surface can occur through high temperature contact during processing and chemical and mechanical interactions after manufacture. The response of the air and tin sides of float glass to such interactions occurring during manufacture and in service is expected to be different and they are investigated in this work. The response of this type of glass to mechanical contact from room temperature to 600 deg C is investigated through instrumented micro-indentation using Vickers and tungsten carbide spherical indenters. As expected, hardness and elastic modulus are observed to decrease with temperature and a factorial experiment is on-going to study the effects and interactions of loading rate, dwell time and surface chemistry. Nanoindentation, SEM/EDX and 4-point load bending have been used to study the nanohardness, reduced modulus and fracture strength of specimens exposed to accelerated weathering conditions of 40 deg C and 95% R.H. for 3, 7, 15, 19 and 49 days. A significantly more rapid deterioration of the air side as compared to the tin side was observed. The significance of these results for the performance of float glass in service will be discussed.
