How Does Crazy Glue Work?

Properties

The active ingredient of Krazy Glue is ethyl 2-cyanaocrylate. When the glue is exposed to moisture, as in the air, the chemicals form long chains, or polymers. It sticks stuff together that does not have a lot of holes; it also sticks well to items that contain some water (like skin!).
Krazy Glue lifts up when pried; therefore, it is not necessarily permanent when applied to a smooth, flat item such as glass. However, don't count on this glue to be semipermanent; it is very sticky! Store in a container with a desiccant like silica gel.

History

In the mid-twentieth century, the scientist Harry Coover stumbled upon the main ingredient in Krazy Glue as he was working on a project to improve weaponry. He rediscovered it when he was working on a project involving flying jets and found that the chemical bonded items very well.
The adhesive properties of cyanoacrylate glue were found to be helpful during field surgery in Vietnam when advanced surgical tools were not available.

Removers

Acetone is a reliable solvent for Krazy Glue but should never be used near mucous membranes. Gamma-butyrolactone, although it has been used as a recreational drug, is also a well-known solvent and is a good Krazy Glue remover.
Sweat and time is a safer and preferable option for the removal of Krazy Glue, despite the fact that it takes longer than solvents. You may also place the object in the freezer; the cold loosens the bonds (don't try this on flesh!). On cloth, when the stain is frozen, scrape the glue off.

Other Uses

Folks who do repairs, such as on musical instruments, have noticed that adding baking soda to Krazy Glue can have it harden very quickly. Baking soda is used as a filler material, and the cyanoacrylate glue seals it. Adequate ventilation and heat-protective equipment are necessary, since this process can give off heat and fumes.
Adding cyanoacrylate-based glue to a surface can create a polymer varnish, such as in an electric guitar. Bone dust added to cyanoacrylate glue can make a very hard lacquer. However, breathing on a dried surface of Krazy Glue or using accelerators to make it dry faster can make it foam up and ruin the finish. This process may give off heat and fumes as well, so wear protective equipment and open the windows.
Some hobbyists report that cyanoacrylate is safe on Z foam; however, there are differing types foam, and it may not work well on all types. Common white cooler foam may melt with cyanoacrylate glue.
Cyanoacrylate glue dries much faster than epoxy glues.
Some doctors have been known to use cyanoacrylate glues to seal minor skin lacerations. N-butyl-cyanoacrylate was used in hospital settings and has since been replaced with 2-octyl cyanoacrylate because of its better resiliency. N-butyl-cyanoacrylate is still used in veterinary preparations and dental work, however. It is also used in treating some blood vessel deformations as well as minor birthmarks.
Lay users of Krazy Glue have suggested the following uses, without possibly examining the drawbacks: fake piercings (may burn or irritate the skin, ornament may be difficult to remove) and corals (may be toxic in a fish tank).
Professional forensic scientists use cyanoacrylate glue to locate fingerprints on evidence.

Hobbyists

Cyanoacrylate glue is helpful for woodworking professionals and for household fix-its--for example, broken ceramic holders and wood crafts--Popsicle sticks, toothpicks, and small pieces of leather. Remarkable stories involving Krazy Glue include fixing a leaky boat miles from nowhere.

Warnings

Krazy Glue does not work well on glass. Cotton fibers give off a great deal of heat when added to Krazy Glue; you can burn yourself severely! The glue can cause irritation of the mucous membrane and can give off noxious fumes.