Super glue question?

Question

I am just curious but why does super glue take forever to dry on some materials but dries instantly to your fingers? does it have to do with the oil within the skin?

Answer 1

Instant glues (cyanoacrylate glues) don't "dry" in the traditional sense that white glues and others do.  They *cure* instead.  

What causes them to begin curing is actually humidity, even the humidity from your skin or that's on most other items (a very thin layer that clings to most everything).  

So if you leave a bit of instant glue sitting out in the air, it will take a long time to absorb enough humidity to begin curing, but if you press two surfaces together the amount of moisture on the surfaces is greater than that present in the air (and the glue will also be very thin at that point), so the curing will begin immediately.

You'll also notice that instant glues won't begin hardening for awhile even in containers where the cap is left off.  That's because very little air is actually getting to the glue, and the amount of humidity in that air isn't a lot compared to the amount of glue inside the container so the reaction goes very slowly.

HTH,

Diane B.

Answer 2

Huh,good question,I'm not sure,you may want to ask this in a science category,where all the really "sophisticated" people are,cause i do find this as an interesting question,I'll star you.