How Super Glue Works
If you've ever used it, you'll know that super glue is one product that has earned its name. Far more powerful (and fast acting) than traditional adhesives such as epoxies and white glue, super glue is the go-to sticky for those who need something fixed right the first time. But how does this powerful adhesive work? The main ingredient in super glue is a chemical called cyanoacrylate. This resin uses water and air to cure, explaining the age old question of why super glue doesn't harden in the tube. You may be thinking to yourself "there's no water on that coffee cup I just glued back together", but you're undoubtedly mistaken. Almost everything in the world has at least minute traces of water on the surface, believe it or not, and trace amounts are all cyanoacrylate needs to cure.
How to Best Use Super Glue
Keeping in mind that super glue uses water to harden, you should avoid your instinct of fully drying a surface before attempting to use super glue to do repairs. Actually, super glue will work best in humid, moist areas, which may be the opposite case of your experience with other types of adhesives. In fact, it wouldn't even be a bad idea to wipe a surface with a damp rag before using super glue. While its not advisable to attempt gluing on a dripping wet surface, a little moisture is fine.
What Does Super Glue do When it's Not Glueing?
Interestingly, super glue, or more specifically, cyanoacrylate, has an unexpected use that has nothing to do with its adhesive properties. It has become an invaluable chemical for law enforcement. Warming cyanoacrylate release fumes which can then bring up fingerprints on smooth surfaces. The once invisible fingerprint residue reacts with the fumes to create a soft white polymer, making the fingerprints fully visible to crime scene investigators. From there, photographers can snap pictures of the prints and put them into a database as a way of searching for suspects.