CA glue (cyanoacrylate) is a fast-curing adhesive that hardens by reacting with trace moisture in the air and on the material's surface, not by evaporating like wood glue or contact cement. It's sold under names like super glue and instant glue, and it comes in several viscosities, thin, medium, and thick, because each one is engineered for a different gap size and material.
What Is CA Glue? Cyanoacrylate Explained
As the manufacturer of Starbond CA adhesives, we get some version of this question daily from woodworkers and hobbyists picking up cyanoacrylate for the first time, so here's the straightforward version.
CA stands for cyanoacrylate, the chemical family this adhesive belongs to. It's the same family of glue most people just call super glue. There's no difference between "CA glue" and "super glue" beyond which name the seller uses; woodworkers, modelers, and pen turners tend to say CA glue because the craft community adopted the chemical name, while the retail shelf at a hardware store usually says super glue.
How CA glue actually cures
Unlike wood glue or contact cement, CA glue doesn't cure by drying out. It cures through a chemical reaction with trace moisture, either humidity in the air or the thin moisture layer already present on most surfaces. That reaction is why CA glue can set in as little as 5 seconds even though no heat or clamping is involved, and it's also why cure time varies by surface: a dry, sealed material with almost no surface moisture can take noticeably longer to bond than a slightly porous one.
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The glue contacts the surface and starts reacting with available moisture.
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The reaction triggers a chain polymerization that links the liquid monomer into a solid plastic.
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Full handling strength is usually reached within seconds to a couple of minutes, depending on viscosity.
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Complete cure (maximum bond strength) can take up to 24 hours, even though the joint feels solid much sooner.
Why CA glue comes in different viscosities
A single "CA glue" formula would either run everywhere on tight joints or fail to fill a gap. Starbond makes several viscosities so the glue matches the job instead of the job working around the glue.
|
Viscosity |
Consistency |
Cure time |
Best for |
|---|---|---|---|
|
Thin |
Water-thin (1-3 cP) |
5-15 sec on close joints |
Tight-fitting joints, wicking into cracks, stabilizing porous wood, PLA 3D prints |
|
Medium |
Oil-like (50-150 cP) |
12-25 sec |
General purpose bonding, wood-to-wood repairs, hobby and model work |
|
Thick |
Honey-thick (1,000-2,000 cP) |
25-30 sec |
Gap filling, vertical surfaces, rough or uneven joints |
|
Gel |
Non-drip paste |
5-15 sec |
Overhead applications, soft materials, anywhere the glue needs to stay put |
CA Glue and Accelerator
CA glue cures on its own, but an accelerator (also called an activator) triggers a near-instant cure, dropping the wait from several seconds to under one. This matters most for thick CA on large gaps, for flexible or rubberized materials, and for cold-weather projects where ambient moisture is lower. Starbond sells both aerosol and pump-spray accelerators; if you're deciding which to buy, see the full accelerator buying guide (4.3).
Most Starbond CA glue is sold as part of the Superglue Pro Kit, which pairs the glue with precision microtips and a clog-prevention cap, so a new user isn't guessing at application on top of learning the chemistry.
Shop the Starbond CA Glue Lineup
Frequently Asked Questions
Is CA glue the same as super glue? Yes. CA glue and super glue refer to the same cyanoacrylate chemistry; "CA glue" is simply the term craft and woodworking communities use more often.
What is CA glue used for? Woodworking repairs and joinery, pen turning and woodturning finishes, model and hobby assembly, 3D print bonding, jewelry and inlay work, and general household repairs on wood, many plastics, and rubber.
How long does CA glue take to cure? Handling strength sets in 5 to 30 seconds depending on viscosity; full cure strength develops over roughly 24 hours. Accelerator drops the initial set to under a second.
Is CA glue waterproof? Cured CA glue holds up well to occasional moisture exposure, but it isn't rated for constant submersion or heavy flexing underwater; for those applications, a marine-rated epoxy is the better choice.
Is CA glue food safe? Standard CA glue isn't rated for direct, ongoing food contact. Once fully cured it's inert, but don't use it on surfaces that will regularly touch food without checking the specific product's rating first.
Can CA glue be used on plastic? It depends on the plastic. High surface energy plastics bond well with CA glue; low surface energy plastics like polypropylene and HDPE resist it and need surface prep first.
What's the difference between thin and thick CA glue? Thin CA wicks into tight, close-fitting joints through capillary action and is too runny to bridge a gap. Thick CA is viscous enough to fill gaps and hold on vertical surfaces without running, but takes longer to set without accelerator.
Why did my CA glue turn white or cloudy? This is usually from excess moisture, too much accelerator, or off-gassing from certain woods; it's a cosmetic surface reaction (sometimes called blooming), not a sign the bond failed.