What type of adhesives would you recommend for bonding glass to steel that will be exposed from -20-100˚F in an outdoor environment?
Dr. Dave explains why this type of application can often be tricky, particularly due to the large differences in thermal expansion coefficients between the glass, the steel, and the adhesive.
You don’t indicate which substrate is on the outside, and this does make a difference in the possible choice of adhesive. Epoxy adhesives were traditionally used for this application, but they should be used with care as they may be too rigid. In addition, if the glass is exposed to daylight, epoxies are somewhat sensitive to UV radiation and may discolor or degrade.
This type of application can often be tricky, particularly because you have to deal with the large differences in thermal expansion coefficients between the glass, the steel, and the adhesive. The ideal adhesive would have its own thermal expansion coefficient midway between that of the glass and the steel, but this is difficult to achieve and cracking of the glass may occur in certain applications. Some degree of flexibility in the adhesive will help to dissipate stresses in the bond line.