Sunday, September 30, 2012

Adhesive Should I Use To Glue Neodymium Magnets

Neodymium magnets are powerful magnets used in many different applications. Most magnets purchased from stock are nickel plated. Nickel is an excellent choice to protect the magnet as it is very resistant to attack by corrosives. Unfortunately, the same great properties of nickel that make it ideal to protect the magnet make it difficult for adhesives to form a chemical bond to adhere to the substrate. In addition, the process of plating with nickel creates a surface that is extremely smooth and hard, further reducing the ability of the adhesive to create a satisfactory bond to the metal.
When using stock neodymium magnets, the types of glue that actually work are very limited. The best choice is a two part epoxy adhesive. These glues are mixed just before use, creating their own chemical reaction to adhere the magnets to another object.
Before attempting to glue stock Neodymium magnets, users should take time to prepare the surface to interact with the glue and create the best possible bond. Begin by cleaning and degreasing the surface of the nickel plating. This will require the use of an industrial solvent degreaser. Household detergents and alcohol do not have the degreasing power to effectively clean the magnet and prepare it for gluing. Once the grease is removed, use a 200 grit emery cloth to abrade the surface. The goal is to create a surface with enough texture for the glue to grip and without breaking through the nickel, which would allow the magnet to corrode. After abrading the surface, clean and degrease a second time. To test the preparation, place a few drops of water on top. If the water spreads to wet the surface and does not bead, it is ready to receive the adhesive and form a strong bond. Be sure to allow the surface to dry before mixing the adhesive and attempting to glue the magnet to the surface.
The surface to which the magnet will be adhered will also need to be prepared to receive the magnet. Be sure that it is also free of grease, dust or other debris. If this surface is also extremely smooth like the nickel plated Neodymium magnet, it may be necessary to abrade this surface as well.
Mix the epoxy according to package directions. Normally, this involves mixing equal parts of the hardner and the adhesive. Only mix the amount of adhesive that can be used in a short period of time. Apply to the magnet and attach to the surface. Clamp in place to dry if necessary.
Stock Neodymium magnets are plated with extremely hard and smooth nickel, which prevents bonding with most adhesives. With proper preparation, the magnets will adhere to most surfaces using a good quality two part epoxy adhesive.

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