Neodymium magnets are incredibly strong.
But gluing them securely can be tricky.
In this post, we’ll cover everything you need to know to achieve a lasting bond.
You’ll learn the best adhesives to use for different applications.
We’ll share tips for properly preparing the surfaces for maximum adhesion.
And we’ll highlight the common mistakes to avoid that can cause glue failure.
By the end, you’ll be equipped to tackle any magnet gluing project with confidence.
Let’s dive in!
Best Glues
Below you can find some of the best glues and adhesives for attaching neodymium magnets.
Two-part epoxy
This is one of the most highly recommended options.
Epoxies bond well to the nickel plating on neodymium magnets and provide a very strong hold.
5-minute epoxies are a good choice.
Cyanoacrylate (super glue)
Super glues like Loctite and Gorilla Glue gel can work well.
Especially for smaller magnets and lighter applications.
Use the thicker “gap filling” varieties for best results.
Urethane adhesives
One common brand can be Gorilla Glue.
These provide good bonding strength to the magnet and various surfaces.
Silicone adhesives
Silicone provides a flexible bond that can help absorb shock.
Products like E6000 and Sugru moldable glue work well with magnets.
JB Weld
Other metal-reinforced epoxies will work as well.
These are very strong but can be attracted to the magnet, so use carefully.
Best for high-strength applications.
Bonus: Extra tips
- Avoid hot glue guns, as the heat can demagnetize the magnets
- Roughen up the magnet surface with sandpaper to help the glue adhere better
- Clean the surfaces thoroughly with rubbing alcohol before gluing
- Allow proper curing time for maximum bond strength
The best glue depends on your specific application, but in general a two-part epoxy or thicker super glue will provide the strongest bond for neodymium magnets. Proper surface preparation is also key to achieving a lasting hold.
Clean before Gluing
Below are the key steps to properly clean neodymium magnets before gluing.
Follow these tips, and you obtain good bonding results.
Remove dirt and debris
Use a soft cloth or sponge to wipe down the surface of the magnet and remove any loose dirt, dust, or debris.
Degrease the surface
Clean the magnet thoroughly with a degreasing agent like acetone or isopropyl alcohol to remove any oils or grease. This is critical for achieving a strong bond.
Abrade the surface
Lightly sand the nickel plating on the magnet with fine-grit sandpaper to roughen it up.
This gives the glue more surface area to adhere to.
Clean off any sanding dust afterwards.
Final cleaning
After abrading, clean the magnet again with alcohol and allow it to dry completely. The surface should be free of any contaminants before applying glue.
Prepare the mating surface
Clean and abrade the surface you are gluing the magnet to as well.
Especially if it is metal or a smooth plastic.
This will help the adhesive bond.
Bonus: Additional tips
- Wear gloves when handling the magnets after cleaning to avoid getting skin oils on the surface
- For stubborn dirt or rust, a rust remover or ultrasonic cleaner may help
- Allow proper drying time after cleaning and before gluing
- Select an appropriate adhesive for your application, like epoxy, cyanoacrylate, or silicone
In summary, thorough cleaning, degreasing, and abrading of the magnet surface is essential for achieving a strong, lasting bond when gluing neodymium magnets.
Proper surface preparation will help avoid failures and detachment of the magnets during use.
Properly Apply Adhesive
Here are the key steps to properly apply adhesive when gluing neodymium magnets:
Apply the adhesive evenly
Put a small amount of glue on one of the surfaces.
Enough for good coverage but not so much that it will squeeze out excessively.
Avoid air bubbles.
Press the surfaces firmly
Attach the magnet to the surface and apply steady.
Even pressure for a few minutes to allow the adhesive to begin setting.
Use clamps if needed to maintain pressure.
Allow proper curing time
Let the bond cure fully before putting any stress on the joint.
Most adhesives require 24 hours to reach maximum strength.
But epoxies may take even longer.
Avoid moving the parts during this time.
Bonus: Additional tips
- For better adhesion to wood, remove any finish and glue directly to the bare wood
- If gaps are unavoidable, use a gap-filling adhesive or add foam tape
- Test a small sample first to check adhesive compatibility with the surfaces
- Handle the magnets carefully as they can pinch fingers when attracted to each other
In summary, proper surface preparation, adhesive selection, and curing time are essential for creating a strong, lasting bond when gluing neodymium magnets.
Following these best practices will help ensure your magnet stays securely attached to the desired surface.
How Long before Gluing
Here are the key steps for cleaning neodymium magnets before gluing.
Wipe the magnet surface with a degreasing solvent like acetone or isopropyl alcohol to remove any oils, grease or contaminants.
- Allow it to dry completely.
Lightly sand or abrade the nickel plating on the magnet with fine-grit sandpaper to roughen up the surface.
- This gives the glue more surface area to adhere to.
Clean off any sanding dust with alcohol and let the magnet dry thoroughly.
- The surface should be free of any residue before applying glue.
In terms of how long to clean the magnets, the key is allowing sufficient drying time after each cleaning step:
- After the initial degreasing with solvent, let the magnets air dry for a few minutes until no residue remains.
- After abrading the surface, clean off the dust and allow to dry again, typically just a minute or two.
The final cleaned magnet surface must be completely dry before applying any adhesive.
- This may take 5-15 minutes depending on the cleaning solvents used.
So in summary, the actual cleaning process is fairly quick, but it’s important to allow proper drying time after degreasing and after removing any sanding dust.
Expect to spend around 15-30 minutes in total to thoroughly clean, abrade, and dry the magnets before they are ready for gluing.
Careful preparation of the magnet surface is essential for achieving a strong, lasting adhesive bond.
Common Adhesive Failures
Below are some of the most common causes of adhesive failure when gluing neodymium magnets.
Improper surface preparation
Not cleaning and degreasing the magnet surfaces thoroughly before gluing is a major cause of bond failure.
Oils, dirt and other contaminants can prevent the adhesive from adhering properly.
Using the wrong type of adhesive
Neodymium magnets require strong adhesives designed for bonding metal.
Using weak glues like hot glue or those not rated for the material can lead to the magnets detaching.
Insufficient curing time
Rushing to use the glued magnets before allowing the adhesive to fully cure.
Usually 24 hours, is a common mistake that leads to premature failure of the bond.
Excessive force or impact
Neodymium magnets are very brittle. Allowing them to slam together with high impact, even when glued, can crack the magnets and damage the adhesive bond.
Exposure to high temperatures
Many adhesives soften and lose strength when exposed to high heat.
Exceeding the maximum operating temperature of the magnets themselves can also degrade the magnetic properties and attached adhesives.
Corrosive environments
Exposure to moisture, chemicals, and salt can corrode the neodymium magnets.
This may cause the nickel plating to peel away from the crushed magnet material underneath, taking the glue with it.
Inadequate adhesive coverage
Applying too little glue or not spreading it evenly, especially on larger magnets, can result in a weak bond prone to failure.
The entire mating surface needs to be coated.
In summary, the keys to avoiding adhesive failure are proper surface preparation, using a strong metal-bonding adhesive with full coverage, allowing sufficient curing time.
And not exposing the assembly to excessive forces, impacts, heat or corrosive elements.
Following the adhesive manufacturer’s instructions closely will help ensure a lasting bond.
Common Mistakes to Avoid
here are some common mistakes to avoid when gluing neodymium magnets.
Not cleaning and degreasing the surfaces thoroughly
Dirt, oils, and other contaminants can prevent the glue from adhering properly. Always clean the magnet and the surface you are gluing it to with rubbing alcohol or a degreasing solvent before applying adhesive.
Not roughening up smooth magnet surfaces
The nickel plating on neodymium magnets is very smooth. Sanding or abrading the surface slightly will give the glue more texture to grip onto for a stronger bond.
Using the wrong type of glue for the material
Different adhesives work better on different surfaces. For example, two-part epoxy is best for metal and wood, while plastic may require a specific plastic-bonding glue. Using the wrong adhesive can lead to a weak bond.
Applying too much or too little glue
Excess glue can add unwanted weight and may attract the magnets in unintended ways.
Too little glue will result in a fragile bond. Apply just enough for good coverage.
Not allowing sufficient drying/curing time
Rushing to use the glued magnets before the adhesive has fully cured is a common mistake. Follow the manufacturer’s recommendations and allow ample time, usually 24 hours, for maximum bond strength before handling.
Using hot glue, especially on neodymium magnets
The heat from hot glue can demagnetize neodymium magnets. Avoid hot glue entirely or use cool-temperature glue on ceramic magnets only.
Exposing the bond to excess force too soon
Even after curing, avoid putting too much stress on the glued joint for the first few days to allow the bond to reach full strength.
In summary, proper surface preparation, glue selection, application technique, and curing time are all critical for achieving a strong, lasting bond when gluing neodymium magnets.
Avoiding these common errors will help ensure your magnet adhesion project is successful.