Cyanoacrylate adhesives, commonly known as CA glues or super glues, are fast-curing glues that form strong bonds in seconds. But is there a difference between CA glue and super glue?
CA Glues and Super Glues
CA glue and super glue are often used interchangeably, but they are not completely identical products. However, they share some common characteristics:
- They are cyanoacrylate-based adhesives that cure rapidly when exposed to moisture. This allows them to quickly bond materials together in just seconds or minutes.
- They can be used to bond a wide variety of materials like plastic, rubber, metal, wood, ceramic, paper, leather and more. This makes them versatile adhesives for many DIY, craft, home improvement and industrial applications.
- They form strong, rigid bonds that are resistant to heat and chemicals. The cured glue creates a thermoplastic bond that can be softened with heat but will return to its solid state upon cooling.
While CA glue and super glue are very similar, there are some subtle differences between the two terms that are worth noting:
- CA Glue is the industrial name for cyanoacrylate adhesive. It encompasses all grades and viscosities of cyanoacrylate-based glues used for industrial, manufacturing, and specialty applications.
- Super Glue is a consumer brand name for fast-curing cyanoacrylate adhesives. It refers primarily to low-viscosity, general purpose glues used for home, office and hobbyist projects. Popular consumer brands include Krazy Glue and Gorilla Glue.
Chemical Composition
The key component of both CA glue and super glue is cyanoacrylate. This unique adhesive molecule has the ability to rapidly polymerize (link together to form chains or networks) in the presence of moisture, creating strong bonds between surfaces.
Specifically, CA glues and super glues consist of an ethyl or methyl-based cyanoacrylate monomer. The most common types are:
- Ethyl cyanoacrylate – The primary component in many consumer super glues and thin CA glues. It offers a fast cure time and can bond a wide range of materials.
- Methyl cyanoacrylate – Used in some industrial CA glues and “super glue for plastics” products. It bonds plastics strongly but has a slower cure time than ethyl cyanoacrylate.
- Methoxyethyl cyanoacrylate – A modified cyanoacrylate found in some medical-grade adhesives and specialty glues. It has a slower curing time and flexible bonds.
Curing Process and Bonding Mechanism
CA glue and super glue cure through a rapid moisture-initiated polymerization process. Here is how it works:
- Cyanoacrylate monomers in the glue are spread in a thin layer between two surfaces to be bonded.
- Trace moisture on the surfaces acts as an initiator and triggers the monomers to link together in long chains, forming cyanoacrylate polymer fibers.
- The fibers interlace and create a strong, rigid bond that continues to cure and strengthen over the next 24 hours.
- The cured CA glue or super glue creates a thermoplastic bond. It can be softened with heat but will return to its solid state upon cooling.
This moisture-activated curing reaction is extremely fast, which is why CA glues and super glues bond surfaces so quickly. The process gives them their reputation as a “super fast glue”.
However, the speed of the curing process can vary based on:
- Humidity – More moisture in the air accelerates curing. Low humidity increases cure time.
- Gap Between Surfaces – Thinner bond gaps promote faster curing. Larger gaps take longer to cure.
- Cyanoacrylate Type – Methyl cyanoacrylate takes longer to cure than ethyl cyanoacrylate.
- Surface Chemistry – Porous or acidic surfaces initiate faster curing. Non-porous and basic surfaces are slower.
Comparing CA Glue vs Super Glue
Now that we’ve covered the basics of cyanoacrylate adhesives, let’s directly compare some of the characteristics between industrial CA glues and consumer super glues:
Curing Time
- CA Glue – Cure time can range from 5 seconds to over 1 minute depending on type, gap, and conditions.
- Super Glue – Most super glues cure in 5-30 seconds. Designed for very fast cure.
Viscosity
- CA Glue – Offered in a wide range of viscosities from 1 centipoise liquid to gel.
- Super Glue – Primarily very low viscosity liquids intended for capillary flow into bonds.
Performance
- CA Glue – Can be formulated for high strength, flexibility, heat/solvent resistance, and specialty applications.
- Super Glue – General purpose for minor repairs. Suitable for basic applications.
Brands
- CA Glue – Brands include Loctite, Bob Smith Industries, Starbond, Stick Fast, and Permabond.
- Super Glue – Popular brands are Krazy Glue, Gorilla Glue, and Loctite Super Glue.
Price
- CA Glue – Industrial grades can range from $10 to $50 per ounce.
- Super Glue – Consumer-sized tubes often under $5 per ounce.
Applications
- CA Glue – Used extensively in manufacturing and industry. Also used for crafting and hobbies.
- Super Glue – Mainly used for minor household repairs, crafts, and quick fixes.
Selecting the Best CA Glue
With so many options for cyanoacrylate adhesives, how do you choose the best CA glue? Here are some tips:
- Consider the materials – CA glues bond plastics, rubber, metals, wood, and more. Select a formula compatible with your materials.
- Mind the gap – Thin, low-viscosity CA works best in tight spaces. Thicker gels are better for wider gaps.
- Factor in curing time – If you need extra fast curing, look for quick-bonding ethyl cyanoacrylate glue.
- Get the right viscosity – Thin liquid CA glues wick into joints. Thick gels prevent run-off. Medium viscosities offer control.
- Check flexibility – Some CA glues remain rigid and brittle. Flexible formulas allow some movement.
- Review performance ratings – Check manufacturer specs for tensile, shear, and impact strength.
- Buy from reputable brands – Loctite, Starbond, and Bob Smith offer consistent, high-quality CA glues.
- Consider shelf life – Unopened CA glue lasts 12-18 months. Refrigeration extends shelf life.
Tips for Using CA Glue
Once you’ve selected the best CA glue for your project, proper technique is key to achieving effective bonds:
- Ensure surfaces are clean, dry, and free of dirt, grease, or oil. Roughen smooth plastics with sandpaper.
- Avoid over-gluing. A thin layer of CA glue is all that’s needed. Too much glue can weaken the bond.
- Dispense glue precisely using the applicator tip. Be careful not to get CA glue on your fingers.
- Hold parts together firmly for 30-60 seconds until set. Do not disturb or reposition during curing.
- Allow 24 hours for the CA glue bond to fully cure before stressing or testing the joint.
- Apply activator sprays or liquids to accelerate curing times. Be careful not to over-apply.
- Store unused CA glue properly by keeping containers sealed and refrigerated if possible.
- Wear eye protection and work in a well-ventilated area. CA fumes can irritate eyes and skin.
CA Glue vs Super Glue for Plastic
One of the most common uses of CA glue and super glue is bonding plastic parts. Both can be used effectively for plastic, but there are some differences:
Suitability for Plastics
- CA Glue – Formulated for plastics bonding. Ethyl and methyl cyanoacrylate work well.
- Super Glue – Bonds most plastics but sometimes weaker than industrial CA plastic glues.
Cure Time
- CA Glue – Quick-cure ethyl cyanoacrylate options available. Methyl CA glue cures slower.
- Super Glue – Very fast cure, usually in under 1 minute. Good for impatient plastic bonding.
Bond Strength
- CA Glue – Stronger when using plastic-specific CA glue rather than multi-purpose super glue.
- Super Glue – Adequate strength but can be more brittle on plastics than formulated plastic CA glues.
Viscosity
- CA Glue – Thin, medium and thick CA glues allow flexibility for plastic bonding.
- Super Glue – Thin viscosity works well for tight-fitting plastic joints.
Durability
- CA Glue – More resistant to temperature fluctuations and moisture when using plastic-formulated CA glues.
- Super Glue – Prone to degradation over time when exposed to moisture or temperature changes.
For high strength, durable plastic bonding, opt for plastic-specific ethyl or methyl cyanoacrylate CA glues. For convenience and speed, super glues work reasonably well on plastics too.
CA Glue vs Super Glue for Wood
In addition to plastics, CA glue and super glue are commonly used to bond and repair wood materials. Here is how they compare for woodworking applications:
Suitability for Wood
- CA Glue – Bonds wood quickly. Resists moisture better than standard wood glues.
- Super Glue – Works on wood but not as strong or moisture resistant as CA wood glues.
Cure Time
- CA Glue – Ethyl cyanoacrylate CA glue cures very fast on wood, sometimes under 10 seconds.
- Super Glue – Also cures quickly on wood, generally within 30 seconds.
Bond Strength
- CA Glue – Stronger when using wood-formulated ethyl cyanoacrylate CA glue.
- Super Glue – Adequate for minor wood repairs but not as strong as wood-specific CA glue.
Viscosity
- CA Glue – Thin options wick into wood joints. Thick gels prevent run off on vertical surfaces.
- Super Glue – Thin super glue absorbs well into wood but can drip.
Sanding/Finishing
- CA Glue – Can be sanded and finished like wood after curing. Some CA glues soak invisibly into wood.
- Super Glue – Cured glue residue may need to be scraped or sanded off before finishing wood.
For robust wood bonds, a wood-formula ethyl cyanoacrylate CA glue is recommended. Super glue works in a pinch but may not offer the same performance.
Best CA Glue and Activator Combinations
Using a CA glue accelerator or activator allows the glue to cure almost instantly. This offers greater convenience and control. Here are some top CA glue and activator pairings:
Starbond EM-02 with Starbond EM-02 Activator
- CA Glue – Medium viscosity ethyl cyanoacrylate adhesive. Bonds metal, plastic, wood, ceramic, rubber and more.
- Activator – Matching spray accelerates cure time to under 5 seconds. Allows precise glue placement before spraying.
Bob Smith Industries BSI-157H with BSI-157 Activator
- CA Glue – Low-odor, low-bloom ethyl cyanoacrylate glue ideal for plastics and rubbers.
- Activator – Non-flammable aerosol activator sprays on evenly. Speeds cure time significantly.
Loctite 401 Prism with Loctite 7452 Activator
- CA Glue – Flexible ethyl cyanoacrylate formula resists impact and vibration.
- Activator – Aerosol spray accelerates cure time and provides easier application control.
Gorilla Super Glue Gel with Gorilla Super Glue Activator Spray
- CA Glue – Anti-clog gel formula ideal for vertical surfaces and porous materials like wood.
- Activator – Mist-on spray speeds Gorilla Super Glue Gel cure time to just seconds.
Using a compatible CA glue and activator system allows for fast, convenient curing with easier application control. This helps maximize the effectiveness of CA glue bonds.
CA Glue vs Epoxy vs Super Glue
How does CA glue compare to other popular adhesives like epoxy and traditional super glue? Here is a detailed comparison:
Cure Time
- CA Glue – Cures in 5 seconds to 1 minute. Very fast bonding.
- Epoxy – Cures in 5 minutes to 24 hours depending on formula. Slower curing.
- Super Glue – Also cures rapidly, within 1 minute. Fast bonding.
Bond Strength
- CA Glue – High strength but more brittle bonds. Resists moisture and chemicals.
- Epoxy – Strong bonds with high resistance to shock, heat, chemicals and moisture.
- Super Glue – Strong but prone to degradation over time. More brittle than epoxy.
Viscosity
- CA Glue – Available in various viscosities from thin liquid to thick gel.
- Epoxy – Offered in liquid and putty consistencies. Can be thinned.
- Super Glue – Primarily very low viscosity for wicking into joints.
Gap Filling Ability
- CA Glue – Minimal gap fill. Best for tight precision joints.
- Epoxy – Excellent gap filling properties. Can bridge larger voids.
- Super Glue – Capable of small gap fills but not as effective as epoxy.
Applications
- CA Glue – Ideal for rapid bonding of close-fitting materials. Wide usage.
- Epoxy – Versatile adhesive and sealant for heavy duty bonds.
- Super Glue – Convenient and fast minor repairs. Limited heavy duty use.
Oily Glue vs Super Glue for Plastic
For certain plastics, oily glues like polyurethane can outperform super glue. Here’s how they compare:
Viscosity
- Oily Glue – Typically thick liquids or gels that resist running and dripping.
- Super Glue – Very thin viscosity intended for capillary action into joints.
Gap Filling
- Oily Glue – Excellent gap filling properties, ideal for uneven plastic surfaces.
- Super Glue – Does not fill gaps well. Requires a tight-fitting joint.
Cure time
- Oily Glue – Slower curing, from 5 minutes to 12 hours after mixing.
- Super Glue – Very fast, bonding surfaces in under 1 minute.
Flexibility
- Oily Glue – More flexible bonds. Absorbs shock and vibration better.
- Super Glue – Forms rigid, brittle bonds with less flexibility.
Chemical Resistance
- Oily Glue – Broad chemical resistance. Handles oils, solvents and corrosives.
- Super Glue – Prone to degradation from chemicals over time.
For plastics that require gap filling or flexibility, oily glues offer better performance. For tight precision joints, super glue works very well on plastic.
Best CA Glues for Common Materials
Here are top CA glue recommendations for bonding different materials:
Plastic
- Loctite Plastics Bonding System – Formulated for plastic, provides superior strength on polystyrene, PVC, acrylics, fiberglass and more.
- Bob Smith Industries BSI-157H – Low-odor ethyl cyanoacrylate that bonds plastic strongly with some flexibility.
- Starbond EM-2000 – Medium viscosity CA glue ideal for plastic model assembly and repair.
Wood
- Starbond EM-02 – Popular thin CA glue that absorbs deeply into wood for a strong bond. Allows rapid woodworking.
- Bob Smith Industries BSI Super Gold+ – Low-bloom ethyl cyanoacrylate engineered for superior wood bonding and finishing.
- Gorilla Super Glue Gel – Anti-clog gel formula is ideal for use on vertical wood surfaces and overhead bonding.
Metal
- Loctite 401 Prism – Flexible, impact-resistant CA glue resists vibration and shock loads on metal parts.
- Bob Smith Industries Insta-Bond Gap Filling – Thick cyanoacrylate formula fills gaps on uneven metal surfaces.
- Starbond EM-150 – Medium viscosity metal-bonding CA glue with higher heat resistance than standard super glues.
Ceramic/Glass
- Loctite Glass Glue – Formulated to bond glass and ceramic while withstanding high temperatures, washing, and microwaving.
- Bob Smith Industries BSI-157 – Low-odor ethyl cyanoacrylate that bonds glass and ceramic stronger than regular super glues.
- Pratley Quickset Clear – Optically clear CA glue designed for invisible repairs of glass, china, and ceramic items.
CA Glue Safety Tips
Despite their convenience, CA glues should be handled with care:
- Work in a well-ventilated area since vapors can irritate eyes and skin.
- Wear gloves and eye protection when handling. Use extreme care not to bond skin or eyes.
- Avoid contact with fabrics and clothing. CA glue bonds to skin and ruins clothing.
- Never intentionally inhale CA glue vapors. This can damage nasal passages and lungs.
- Store upright in a cool, dry location away from heat and moisture. Refrigeration can extend shelf life.
- If accidental skin bonding occurs, soak in warm soapy water and slowly peel apart bonded skin. Do not pull forcibly.
- In case of eye contact, flush with water for 15 minutes and seek medical attention. Do not force eyes open.
- Dispose of used gloves, cloths and applicators properly. Hardened CA glue can slowly release fumes.
Exercising proper safety precautions allows you to take advantage of CA glue’s bonding power while avoiding accidents or mishaps. With responsible use, it is an enormously useful adhesive.
Conclusion
While CA glue and super glue are very similar cyanoacrylate-based adhesives, there are some subtle differences between the industrial and consumer products:
- CA Glue offers a wider range of viscosities, curing speeds, and performance levels for specialty applications.
- Super Glue provides very fast bonding and convenience for home repairs and crafts.
By selecting the right CA glue formula and using proper application technique, strong and rapid bonds can be achieved on plastics, metals, wood, glass, and more. With responsible use, CA glue is a versatile adhesive that opens up new possibilities for both industrial manufacturing and home projects.