The impact of temperature and humidity on bonded repairs performed in the field

In this investigation, sandwich and laminate single lap-shear specimens were manufactured in cold, ambient and hot environments using five typical adhesives commonly used for bonded repairs conducted in the field. The use of these adhesives in these environments, and resulting mechanical strength of repair were evaluated. The results indicate that in most instances, the hot environment proved favourable for adhesive handling and application, but dramatically reduced adhesive gel time and the effectiveness of surface treatment procedures. Flatwise tension strength of the sandwich specimens was not affected, and single lap-shear strength performance varied for each of the adhesives. In the cold environment, adhesive handling and application was relatively difficult, whilst the single lap-shear strength was found to improve, likely resulting from improved effectiveness of surface preparation procedures in this environment.