Something else about crazy (cyanoacrylate) glue.

[kinsler33]

I bought a zillion little tubes of Harbor Freight Crazy Glue today and, for lack of anything more interesting to distract me, read the directions on the back. "Do not wear cotton or wool clothing," it said. Huh?

So I looked it up and yep: " If uncured CA comes in contact with cotton and wool fibers a strong chemical reaction will occur. This reaction is a powerful and produces intense heat that may cause burns." The authority is the website of an outfit that sells eyelash extensions, which are fake hairs that you glue to your eyelashes to look like Zsa Zsa Gabor or perhaps Lamb Chop. They sell a lot of it.

CA is cyanoacrylate, which is what Crazy Glue is. I've used it since it was invented, and I had no idea the stuff would burn down the joint. Does anybody have experience with this?

 

[Willie X]

Yes, model airplane makers often use the 'fast' or 'hot' varieties that smoke when used on balsa wood or cloth. I would guess somewhere around 400 degrees for a short while. Personally, I've never seen a fire but pretty sure the potential is there. Willie X

 

[Tim Orr]

Good evening!

A few weeks ago, after using cyanoacrylates for years, I had trouble getting the cap off and some spurted onto my cotton t-shirt. I saw smoke and "felt the burn." No flames, but I had a red mark on my belly for days! Left a big hole in the shirt too!

Best regards!

Tim Orr

 

[lwalper]

Woodworking a couple of years ago ... CA glue makes a great, hard acrylic finish .. sweaty hands and CA are not a good chemical combination. Short story — the sweat chemistry catalyses the polymerizing reaction and in just a couple of seconds 3rd degree burns resulted. Be careful with the stuff. I don't know about flames (rather doubt that actually), or "smoke," (rather some kind of chemical fumes), but the stuff does get HOT! and irritates your eyes.

 

[c.kugle]

I worked in the Nuclear power industry for almost 20 years and used an Isocyanate based product all the time. While it may be slightly different but it's root base is the same. The "heat" you are refering to is called an exothermic reaction and can cause burns and melt plastic mixing buckets as well. Funny thing is that "crazy glue" and spray foam insulation are only a few molecules different. Chris.

 

[Schatznut]

I've never felt the burn but have always marveled at the way the stuff can migrate: per the instructions, put one drop on one surface of the two pieces to be joined. Clamp the pieces between thumb and forefinger for a minute. Then discover that either (a) one piece is bonded to your finger and the other is bonded to your thumb, or (b) your thumb and forefinger are bonded together.

There's a lot of information about cyanoacrylates on this page, including a brief description of the reaction with natural fibers - apparently the fibers work as a catalyst for the glue.

Superglue - cyanoacrylate - Molecule of the Month - July 2009 - HTML-only version

 

[kinsler33]

It just occurs to me that automobile "clear coat" finishes are cyanoacrylate or something similar. These are fussy to apply, and I suppose that the heat of the reaction has something to do with it. No, cars aren't clocks, but for people who work with their hands it's something likely worth knowing.

 

[Bernhard J.]

Well, superglue contains cyanoacrylate monomers. Clearcoats used to be a reaction product of acrylic polymers and polyisocynates, nowadays I believe that at least some clearcoats are rather PU based. It makes a great difference whether cyanoacrylate monomers having both functional groups in one molecule are polymerized or whether two polymers with the separate functional groups are crosslinked.

 

[Arthur Cagle]

I heard on a professional woodcarver's site today that superglue has only a five year guaranteed bonding life, and that for wood yellow wood glue like Titebond is permanent, so if using on cases be advised that the two glues are not equally desirable. I can't verify the accuracy of this statement, but the source is very professional.

 

[PatH]

Arthur, just curious.....Did the woodcarvers address hide glue (often the preferred glue for wood case repairs because it's what was originally used and is reversible).

 

[Tim Orr]

Good evening, all!

One more tragic recollection: About 6 years ago, I was getting ready to leave for an NAWCC convention. The night before, while packing, I discovered that the handle on my fancy TravelPro computer case (a premium for which I exchanged a bunch of points on my Amex card) was loose – again. I decided to put a little Loctite Blue 242 on the screws to solve that problem once and for all.

In the morning, I grabbed the handle and it came off in my hand. With little time left, I frantically bound the handle up in black Gorilla tape and headed for the airport. Later, TravelPro told me I could get a new handle and extension rods (couldn't just buy the handle) for the low low price of $150! Got a new computer case for the next trip, but still miss that one.

I admit, I didn't read the instructions on the Loctite, which cited "methacrylate ester" and cautioned against use on plastic. A hard, but well-learned lesson! I don't know if "methacrylate ester" is similar to "cyanoacrylate," but it had its own hazards.

Best regards!

Tim

 

[ChimeTime]

The "heat" you are referring to is called an exothermic reaction and can cause burns and melt plastic mixing buckets as well.

Another common exothermic reaction you might run into is with linseed oil, commonly used as a wood finish. The rags or paper wipes used to apply it can catch fire if casually thrown into a trash can.

 

[lwalper]

Arthur, just curious.....Did the woodcarvers address hide glue (often the preferred glue for wood case repairs because it's what was originally used and is reversible).

Not often. It's too much trouble to use. Luthiers tend to go that direction since it is "reversible" and repairs can be made without damaging the instrument. Titebond is generally the way to go. That, along with dowels or biscuits pretty well ensures the project will stay together.

 

[lwalper]

Another common exothermic reaction you might run into is with linseed oil, commonly used as a wood finish. The rags or paper wipes used to apply it can catch fire if casually thrown into a trash can.

Exothermic, yes. But that's oxidation. If you're not going to enclose the used rags in a sealed metal can, spread them out to increase the exposed surface and heat radiating area which reduces the temperature of the oxidizing process. It still oxidizes, but at a lower temperature until it "dries" (is fully oxidized).

 

[Uhralt]

Good evening, all!

One more tragic recollection: About 6 years ago, I was getting ready to leave for an NAWCC convention. The night before, while packing, I discovered that the handle on my fancy TravelPro computer case (a premium for which I exchanged a bunch of points on my Amex card) was loose – again. I decided to put a little Loctite Blue 242 on the screws to solve that problem once and for all.

In the morning, I grabbed the handle and it came off in my hand. With little time left, I frantically bound the handle up in black Gorilla tape and headed for the airport. Later, TravelPro told me I could get a new handle and extension rods (couldn't just buy the handle) for the low low price of $150! Got a new computer case for the next trip, but still miss that one.

I admit, I didn't read the instructions on the Loctite, which cited "methacrylate ester" and cautioned against use on plastic. A hard, but well-learned lesson! I don't know if "methacrylate ester" is similar to "cyanoacrylate," but it had its own hazards.

Best regards!

Tim

I tried to glue back a piece that broke off a 3d printed toy with super glue. The result was that the 3d print melted where it came into contact with the glue, without bonding. It seems the glue acted as a solvent in this case.

Uhralt

 

[Arthur Cagle]

Arthur, just curious.....Did the woodcarvers address hide glue (often the preferred glue for wood case repairs because it's what was originally used and is reversible).

No, he was just referring to gluing pieces of wood that broke off in the process of carving. I would think hide glue has proved its mettle over time...he was just concerned that the crazy glue was not really permanent.

 

[MartinM]

Well, superglue contains cyanoacrylate monomers. Clearcoats used to be a reaction product of acrylic polymers and polyisocynates, nowadays I believe that at least some clearcoats are rather PU based. It makes a great difference whether cyanoacrylate monomers having both functional groups in one molecule are polymerized or whether two polymers with the separate functional groups are crosslinked.

Crosslinked polymers are really odd things. I recently learned that the rubber component, as vulcanized in a tire, is essentially a single molecule.