I know there are chemists on this site because I get corrected by them with uncomfortable frequency. But that’s another story.
My question is about super glue and closed cell foam.
The background of the question starts with mee sitting in a 2006 tying show making foam flies with super glue. [See http://www.flytyingforum.com/pattern6910.html for the pattern I was tying]. Sitting next to me was a PhD chemist who explained that the reason super glue worked so well was that it caused a chemical reaction with the surface molecules of the closed cell foam – and then he went into chemistry that lost me completely. Like I said, that’s another story. Anyway, I had been using super glue for closed cell foam for quite a while and knew what it did, just not why.
So…here’s the question. What is the chemical reaction between super glue and closed cell foam
and…is it as permanent as it seems?
CoachBob, I don’t know why it works either but it sure speeds up the tying time and holds the foam to everything from the thread on the hook to foam to foam. I’m tying up some foam hoppers for a fly swap and I’m using the heck out of it. Jim
ive always heard it was water that causes superglue to harden. this would explain why it would glue so effectively youre fingers together. it reacts with the water in youre skin(or in most cases the water vapor in the air) which causes it to harden.
Superglues or “cyanoacylates” are cure by the crosslinking (polymerzation) of their reaction with weak bases…(water, aochol, blood, etc) So when you glue your fingers together…You are actually crosslinking the very thin layer of moisture on one finger to the very thin layer of moisture on the other finger?Hense making a Bridge between the two fingers…which can easily be broken …depending upon how much dry dead skin you have. This is why super glue bonds wounds very well…all the presece of blood & bodily fluids to react with .
Now to the closed cell foam… Craft foam is a polyurethane closed cell foam. It is a polyol (weak base) resin reacted with an isocyanate…the isocyanates are similar chemisty to the super glue. So not only does the super glue react with the thin layer of moisture on the foam, but it actually crosslinks with the polyol resin (left over unreacted sites) within the foam…so the Bond is much greater and will hold better and longer. You will proabably see a failure in other areas of the foam before the foam - super glue- foam bond breaks.
Hope this help _ I could write a whole essay on this–but it would bore everyone to death!!
I’m no doctor…But I did stay in a Holiday inn express last night?.:D:D
I would suggest staying with medial grade for wounds, but I suspect that it is not much differnet…just a good way to charge more? mabe a little differnet solvent or carrier to help out with the “sting.”
I have worked in a machine shop for years.
Super glue works great when you get cut and it a real bleeder. might sting a little when applying lol.
I keep a tube in my tool box all the time, this stuff is great!
Curt
“The super glue that doctors use is different than the type available in hardware stores. Surgical super glue contains types of alcohols that are less toxic to human tissue. The type sold in stores use ethyl of methyl alcohols that can kill cells.”
Ethyl alcohol has certainly killed many a cells…especially brain cells…other wise know as “white lighting” or grain alcohol…
Not saying that link is “bogus” but if you put alcohol in super glue …you get “ROCK”!!! Medicianal glues probably have different inhibitors, esters, or what ever…but it aint alcohols.
Im no chemist, but don’t most alcohols also contain water? Even if they are mostly pure, won’t the alcohol “absorb” water from the surrounding atmosphere? And if water cures the super glue, wouldn’t it be safe to say anything also containing water would cure the glue, and this would include alcohol?
It the polar OH (oxygen and hydrogen) group in the molocule is what crosslinks the super glues…
Water (as you probably know is H20)
an “alcohol” is a molecule that contains an OH group…so all alcohols should cure a super glue (some are very big molecules and the size and location of the aolchol (OH) group may cause “steric hinderance”…the molecule is just too big and get in the way of itself…too crowded…may not cure a superglue)))
But yes many diluted alcohols contain water…but both should cure the glue
