Epoxy vs Super Glue: Which Is Better for Magnets?

Two-part epoxy usually bonds magnets better than super glue because it fills gaps, absorbs impact, and holds up under heat; cyanoacrylate wins only on small, tight-fitting joints that need a 30-second hold.

For the full breakdown, see our best Adhesive for Magnets guide.

A magnet that pops off a fridge clip or shop jig is usually an adhesive-choice problem. Two-part epoxy and cyanoacrylate sit at opposite ends of the bonding spectrum, and the exact product matters more than the category on the label.

Henkel’s data sheets spell out the gap. LOCTITE Power Epoxy Fast Metallic reaches up to 14 N/mm², handles −30 to 150 °C, and cures in 24 hours. LOCTITE Super Glue Professional, a liquid cyanoacrylate, needs no clamps, sets in 15–30 seconds, and is for clean, close-fitting surfaces only.

Which Adhesive Actually Holds a Magnet Better?

Epoxy is the stronger, more durable choice for permanent magnet bonding where impact, heat, or vibration is involved. Super glue is faster and easier when surfaces mate perfectly and load stays gentle.

LOCTITE’s cyanoacrylate cures from airborne moisture without a catalyst, heat, or clamps — hence the seconds-long set — but the film is brittle under peel, impact, and vibration. Epoxy’s resin/hardener reaction produces a tougher, gap-filling bond.

• Super glue (cyanoacrylate): thin, rigid joints; labels, small craft magnets, quick fixtures.
• Two-part epoxy: gap-filling, impact-tolerant, heat-resistant bonds; motor mounts, tool holders, load-bearing jobs.
• Rubber-reinforced cyanoacrylate (LOCTITE 480): a middle path — flexible, more peel- and shock-resistant, still fast.

Side-By-Side: What the Data Sheets Say

How Do You Bond a Magnet Without It Sliding Off?

Clean the surfaces, apply the adhesive correctly, and restrain the magnet until full strength — most failures trace to one of those steps being skipped. Henkel requires clean, dry, oil-free surfaces and light roughening of smooth ones.

1. Identify the magnet coating and substrate; check the technical data sheet first.
2. Remove oil, dust, wax, and paint; let both surfaces dry.
3. Lightly abrade smooth surfaces without cutting through thin coatings.
4. Super glue: about one drop per square inch on one surface, press and hold 15–30 seconds, then leave it. Do not reposition after contact.
5. Epoxy: mix resin and hardener 1:1, apply promptly, and keep the magnet from shifting — attraction drags it off-center during cure.
6. Wait the full cure: 30 minutes is handling strength only; the fast epoxy needs 24 hours.

Henkel’s Power Epoxy excludes polyethylene, polypropylene, and Teflon-equivalent materials. For specific adhesive picks across magnet jobs, this roundup of the best adhesive for magnets is worth a scan before buying.

When Should You Use Each One?

Match adhesive to load, gap, and temperature. Super glue suits fast, clean joints; epoxy suits tough, permanent, or hot jobs. Heat resistance varies widely — cited epoxies range from 120 °C to 200 °C, and load-bearing limits run lower than the headline heat number.

For demanding permanent-magnet work, LOCTITE EA 9514 and EA 3425 are formulated specifically for magnet bonding, with gap fill up to 3 mm and shear strength up to 27 N/mm² on the 3425.

Safety: super-glue vapors irritate and the liquid can bloom, so ventilate and wear nitrile gloves — not PVC or cotton; clean uncured glue with acetone only after checking compatibility. Neodymium magnets can pinch skin and interfere with pacemakers, so keep them away from magnetic-sensitive devices.