If you read the data sheet or the instructions on a consumer package, you will see that the five minutes refers to the gel time; that is, the time when the mixed adhesive becomes immobile. Full cure typically takes up to 24 hours, although parts can often be handled much sooner. The other major benefit of these adhesives is that the hardener is based on relatively non-toxic and non-corrosive chemicals.

These adhesives can give high adhesive strengths, and I have no hesitation in recommending them for many household or industrial applications, but some limitations do exist. Like all epoxies that are cured at ambient temperatures, they tend to have limited high-temperature resistance. They are also not very resistant to severe environments, such as continuous immersion in water, although some special versions perform much better than others. In order to achieve maximum performance from an epoxy adhesive, it is necessary to use hardeners that contain more hazardous chemicals, but these can be handled safely with appropriate equipment and personal protective measures.

 Any views or opinions expressed in this column are those of the author and do not represent those of ASI, its staff, Editorial Advisory Board or BNP Media.