CA Glue

[Susan Kline]

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Well, now, John, that's good to know.

Okay, NO BURNT MEAT, thanks just the same! I now have another reason to 
dislike char-broiled meat, and to be glad I like lamb rare.

The "kicker" full of nasty stuff did indeed accelerate the cure to the 
point that a lot of heat was released.

However, the Elmer's -- now, that's another kettle of fish! The Elmer's 
doesn't give off a nasty smell when it meets the CA -- just the normal CA 
smell. Heat is released, to the point where if one presses two ends of 
bushing cloth together (as when preventing pedal rod jingles) one can feel 
the heat through the cloth. I've never seen smoke come up from using CA and 
Elmer's together, but the CA seems to set up more firmly than if left to 
its own devices.

Titebond seems to work exactly the same way as Elmer's, and I imagine the 
yellow carpenter's glue will as well. I'm sure it's the water which is 
getting the CA to set up -- however, the "glue trick" as I've described it 
in the Journal uses a very tiny amount of CA with a relatively larger 
amount of Elmer's, and this seems to set up just fine, and quickly. In this 
case, the CA could be considered to be holding the joint together after a 
couple of seconds, but after 1/2 hour or so, the Elmer's will have set up, 
so that the strength of bond over time does not really depend on the CA.

Possibly the water in the glue, by absorbing the heat, keeps the fumes down 
by preventing smoking. Anyway, it seems quite benign to me, and I've used 
it for years to glue rubber buttons, shims, loose veneer, ecsaine (Corfam 
replacement), bushing cloth, unusual action parts which are hard to clamp, 
bits of leather on trapwork, ivory, split keysticks, little bits of jigsaw 
work, -- what have you. I don't generally use it to glue things to metal.

If one uses lots of the two glues, the squeeze-out seems sort of clotted 
and foamy. It is white, and doesn't dry clear like Elmer's. It usually 
pulls away easily (as a string) once it has set for a few minutes, which 
can be a plus. When gluing rubber buttons, I've sometimes had trouble 
putting little enough glue on, since the squeeze out can trash a satin 
finish. If it does squeeze out around a button on a piano lid, I carefully 
put a corner of cloth or paper towel down near it, and try to wick up the 
extra -- and then I LEAVE IT ALONE, and don't wipe it at all! (don't ask ...)

I think by now I can say, empirically, that the Elmer's does not seem to 
inhibit polymerization. It seems like a moderate accelerator. As far as I 
know, no one has tested the strength of the bond of CA alone versus CA + 
Elmer's, but my impression is that the white glue improves the CA bond 
strength. I know that the only time I truly _had_ to go to the car to get 
acetone, I had been gluing on a rubber button while I still had a trace of 
white glue on my finger. My thumb and the side of my index finger got so 
thoroughly stuck together I couldn't free them at all until I had worked in 
several applications of acetone. With CA alone I can usually pull fingers 
apart, possibly leaving a thin outer layer of skin behind.

Best,
Susan

At 04:15 PM 8/17/2005 -0500, you wrote:

>As to the first point, Susan, NO!! (Thankfully!)  To quote a Ph.D. in the 
>field (I m more food/flavor chemistry):
>
>
>
>Cyanoacrylate glues contain the group H2C=CH-CN: Where the = represents a 
>double bond between two carbons and there is a triple bond between the 
>carbon and nitrogen of the CN. CN is the 'cyano' group, and a three-carbon 
>chain with a double bond next to another type of multiple bond (or some 
>other form of electron rich group such as a radical or anion) is an 
>'acrylic' group -- the combination gives a relatively high reactivity to 
>the compounds and allows them to polymerize like a plastic. Many non-toxic 
>compounds contain both types of groups, and many medicines have cyano 
>groups. Along with this group, there are other chemicals and can be other 
>chains attached to that cyanoacrylate group in place of one or more of the 
>hydrogens.
>
>There is NO, NONE, NADA cyanide released on curing these glues and 
>hardening. There are some obnoxious fumes released -- some of them just 
>parts that boil out from the heat of the curing reaction. BUT, whenever an 
>organic chemical that contains nitrogen is burned, some cyanogen/hydrogen 
>cyanide is released. This happens with tobacco, meat, veggies, fireplace 
>wood, etc. This release is worst when there is not enough oxygen present 
>in the burning zone to ensure complete combustion -- so if there is a lot 
>of smoke formation, there is more likelyhood of cyanide formation.
>
>Sorry if that s more chemistry than you wanted, but I think it makes the 
>point.  Watch out for smoking rags, etc!
>
>To the kicker issue, I assume that s an accelerant?  Anything with water 
>(a VERY WEAK lye solution would be better) is going to work.  Elmer s may 
>just be getting in the way of the polymerization.  How is the smell 
>irritating (acrid, ammonia, etc)?  That may give some indication of what s 
>going on.
>
>John Delmore
>
>
>
>----------
>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On 
>Behalf Of Susan Kline
>Sent: Wednesday, August 17, 2005 3:28 PM
>To: Pianotech
>Subject: RE: CA Glue
>
>
>
>At 01:54 PM 8/17/2005 -0500, you wrote:
>
>
>The CA glues themselves have very low toxicity.  And although some 
>companies (Sur-Lok, for one) market their products as solvent free , most 
>are 99% methyl or ethyl cyanoacrylate (butyl and octyl cyanoacrylates are 
>used for surgical closures, an indication of their low toxicity!).  Of the 
>two, I would look for one that is ethyl cyanoacrylate, as a little safer 
>than the methyl.  Maybe fewer fumes.  But the fumes, though not terribly 
>toxic, are irritants.  So keep up with the ventilation.  As for safety, 
>anything that works this good, ya gotta be careful with!
>
>John Delmore
>
>
>This is very interesting, John. I've heard rumors that while curing CA 
>glue can emit small amounts of cyanide? Is this true?
>
>Also, can you tell us what is so very irritating about the kicker? One 
>smell and I decided not to use it. And is the bond stronger or weaker if 
>the glue is "kicked"? I "kick" by using it along with white glue 
>(Elmer's), but the effect seems much less violent than the spray-on kicker 
>which is sold for the purpose.
>
>Thanks for letting us pick your brains ...
>
>Susan Kline

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