1 – Cyanoacrylate: An overview
Cyanoacrylate adhesives, or “CA” in shorthand, are one of the fastest setting adhesives on the market today. A lot of different formulations are out there that have setting times that range from just a few seconds to more than a minute. As a general rule, they don’t need to be clamped, so you can hold things in place until the glue dries (in manual fixturing applications). CA monomers (liquid, uncured state) will quickly polymerize (cure, solidify) when there is moisture on the substrate and in the air around them. Once the polymerization process starts, it keeps going on its own, making it a true one-part self-curing adhesive that only needs one part.Characteristics
2 – Characteristics
Cyanoacrylates are very strong because of the long chains of polymer that connect the two surfaces together. CAs can stick to a wide range of materials, like rubber, plastic, metal, ceramic, wood, and more. Can be used at a wide range of temperatures (-40F to +250F), which is good for most things. When you use CA, it makes a strong, waterproof bond that can’t be broken. You can remove it with high heat (above 350 degrees F) or a special debonding solvent, like acetone or nitromethane.
- When clamping is not possible or not ideal, setting things up quickly is important.
- Maintenance, repair, and overhaul (MRO) is a type of application.
- Rubber and engineering plastic bonding applications are ideal with this glue.
- There are times when looks are important and speed of assembly is very important.
- Bonding different materials together
3 – Out of the Ordinary Uses (Some fun facts)
- Cyanoacrylates have been used for a lot of different things for a long time, like:
- In forensic science, fingerprints are made (crime scenes)
- Archaeologists need to keep fragile fossils safe during their work.
- Making a live tortoise’s shell whole again after it was broken
- Putting plastic worms on fish hooks
- Fragments and colonies of saltwater coral can be put on reef rock and plugs.
- Strengthening and sealing a 3D printed model made of grains
4 – Using the Adhesive
There are many ways to put together cyanoacrylates. It’s important to start with a clean, dry surface when you apply it by hand. As soon as the glue is dry, you quickly press and hold together all of the parts. This can happen in less than one minute or more than one minute, depending on how long it takes for the glue to dry and set. You don’t want to spread the drop or bead out. Instead, let it shrink when you join the parts together.
Use the least you need. It usually takes a drop to cover one square inch, but if the surface is porous, you’ll need more. Extra glue doesn’t make things stronger. CA takes longer to dry on some surfaces, but you can use an accelerator to speed it up.
5 – Warnings
The best way to keep glue from getting on your hands and in your eyes is to wear disposable plastic or rubber gloves (non-woven fabric style). As with cutting onions, CA can make your eyes and lungs hurt, but it’s not very dangerous. However, it can burn. It will also stick to skin, so be careful not to get the adhesive on your skin.
6 – Storage and Shelf Life
The size of the container affects how long CA‘s can be stored and how long they can be kept on the shelf or in the pantry. Smaller amounts of something have a shorter shelf life than bigger ones. If the bottle is kept at room temperature, it should last for at least a year or more. Make sure you don’t put open containers in the fridge because that can make the tip clog up and make the glue harden in the container. There is a way to double the shelf life, but only if the bottles haven’t been opened. If they’re cold when you open them, don’t put them back in the fridge.
Other important things to know about cyanoacrylate
- They are great when there is no need for clamping.
- Short cure time: less than a minute
- It’s long-term and waterproof.
- An item that can be buried in water.
- Apply to the surface that is going to be matted with another surface, like a piece of paper.
- Neither expands nor shrinks while treating