Magnetic tape is made of a thin plastic ribbon coated with fine particles of iron oxide or chromium dioxide (Wikipedia, 2023). When passed over an electromagnet, it can be magnetically imprinted with audio, video or data recordings. This allows magnetic tape to be used for sound and video recording as well as data storage.
Magnetic tape was a key technology in early audio and video recording, allowing the capture of sounds and moving images that could be played back later. It revolutionized broadcast media in the mid-20th century. Magnetic tape data storage was the most common form of computer data storage from the 1950s to the 1980s and is still used today for long-term archiving.
Some of the key properties of magnetic tape that have made it useful for audiovisual and data recording applications are its reusability, portability, and ability to allow sequential access to information. It can also store large amounts of data at a relatively low cost.
Metals
Magnetic tape sticks very well to metals that exhibit magnetic properties like iron, steel, nickel, and cobalt. This is because magnetic tape itself contains a coating of fine magnetic material, usually ferric oxide or chromium dioxide. The magnetic properties of the metals cause them to be attracted to and adhere to the magnetic particles in the tape.
Of the metals magnetic tape sticks to, it has the strongest adhesion to iron and steel. This is because iron has the highest magnetic permeability of any element. Steel is an alloy of iron containing anywhere from a few percent to 1-2% carbon. The high iron content gives steel similar magnetic properties to pure iron. So magnetic tape sticks readily to iron and steel surfaces through magnetic attraction.
Nickel and cobalt are also ferromagnetic metals, meaning they exhibit strong magnetism in the presence of an external magnetic field. While not as magnetic as iron, their ferromagnetic properties still allow magnetic tape to stick well. The microscopic magnetic particles on the adhesive side of the tape are drawn to align themselves with the magnetic fields in nickel and cobalt. This magnetic attraction causes secure adhesion.
Plastics
Magnetic tape does not readily stick to most plastics. This is because plastics are non-magnetic materials that lack ferrous (iron) content. Plastics are made from synthetic or petroleum-based polymers that have no magnetic properties. Some common plastics that magnetic tape adheres poorly to include:
PVC – Polyvinyl chloride, commonly known as PVC, is a very widely used plastic. From plumbing pipes to plastic wrap, PVC can be rigid or flexible. Magnetic tape has minimal adherence to the smooth surface of PVC.
Acrylic – Acrylic plastic is found in many household items like windows, shower doors, and aquariums. Products made of acrylics like Plexiglas or Lucite are too slick for magnetic tape to grip onto.
Polycarbonate – Polycarbonate is an incredibly strong and durable plastic. It is used for bulletproof glass, riot shields, and lenses for glasses. Magnetic tape does not bond well to polycarbonate.
In summary, magnetic tape lacks an ability to cling to these non-ferrous plastics. The tape slides right off their smooth and slippery surfaces.
Wood
A Complete Guide to Magnetic Tape mentions that magnetic tape can stick to wood surfaces, but it depends on the specific tape as well as the wood surface. Self-adhesive magnetic tape is often recommended for sticking to wood. However, sealed, painted, or finished wood may present challenges for magnetic tape adhesion. The tape may have difficulty adhering to slick surfaces.
According to this Quora post, various glues and epoxies can help magnetic vinyl strips stick to wood. Cyanoacrylate adhesives (super glue) are suggested. Proper surface preparation is also key – sanding and cleaning the surface can help magnetic tape adhere better. Overall, magnetic tape can stick well to raw wood, but finished and treated surfaces may require additional adhesion methods.
Glass
Magnetic tape does not stick directly to glass. This is because glass is not magnetic, meaning it does not contain iron or other ferrous metals that are attracted to magnets. In order for magnetic tape to stick to glass, there needs to be a layer of metal in between the glass and the tape.[1] This metal layer creates a magnetic surface that the tape can adhere to. Some options for creating a magnetic surface on glass include:
- Attaching a thin strip of steel, iron or nickel to the glass
- Spray painting the glass with magnetic paint that contains iron filings
- Placing a magnetic sheet behind the glass
With any of these modifications, the magnetic tape will be able to stick to the glass through the magnetically conductive material in between. So while magnetic tape does not directly adhere to glass, with a little creativity it can be made to stick.
[1] https://www.findtape.com/videos/magnetic-tape-uses/v7/
Concrete
Magnetic tape does not stick directly to concrete. This is because concrete is not magnetic. For magnetic tape to adhere to concrete, there needs to be a metal layer in between the tape and the concrete surface. The metal acts as an intermediary that the magnetism can pass through.
A common solution is to attach a thin sheet of galvanized steel to the concrete first using construction adhesive or screws. Then the magnetic tape can be applied on top of the galvanized steel sheet. The magnetic attraction passes through the steel into the concrete behind it. This creates a solid bond.
Another option is using magnetic primer paint. After painting a coat of magnetic primer on the concrete and letting it dry, the magnetic tape can stick directly to the primed surface. The ferrous particles in the primer act like the steel sheet to transmit the magnetism.
With proper preparation using a metal intermediary, magnetic tape can be mounted securely on concrete surfaces. But it does not adhere directly without a magnetic base layer.
Drywall
Magnetic tape can stick to drywall, also known as plasterboard or gypsum board, with varying levels of success depending on the type of drywall compound used. According to Magnet.com.au, “The adhesive side of the magnetic tape uses high quality adhesive that will bond with painted timber, gyprock, tile, glass, steel…” (1) However, some types of drywall joint compound have lower porosity and may not allow the adhesive to grip as strongly. Testing a small piece of magnetic tape first is recommended. With standard drywall that has been properly prepared and primed, magnetic tape should adhere sufficiently. But excessive layers of compound or highly polished surfaces may hinder adhesion. Overall, magnetic tape can stick to most types of drywall under normal conditions.
Fabrics
Magnetic tape does not stick directly to most fabrics like cotton, polyester, etc. This is because fabrics themselves are not magnetic or ferromagnetic, meaning they cannot be magnetized or attracted to magnets (source). For magnetic tape to stick to fabric, there needs to be a metal object placed between the tape and fabric, such as a metal curtain rod, buttons, or other embellishments.
Some creative ways to use magnetic tape with fabrics include adding metal grommets or decorative metal pieces to curtains and using magnetic tape to hold the curtains shut. Small metal washers can be sewn into garments at strategic points, allowing magnetic fasteners or embellishments to attach via magnetic tape. Overall, a metal intermediary is required for magnetic tape to adhere to most fabric materials.
Tile
Magnetic tape does not stick directly to tile. This is because tile is not magnetic, so the tape won’t adhere. In order for magnetic tape to stick to tile, there needs to be a metal surface between the tape and the tile. Some options for creating a magnetic surface on tile include:
According to this Reddit thread, one way is to apply adhesive to the back of the magnetic tape, and secure it to the tile surface with strong tape. Small pieces of wood can also be used under the magnetic strip to hold it in place while the adhesive cures.
Another option is to attach a thin metal sheet or magnetic primer to the tile first, and then apply the magnetic strip on top of that. The metal sheet creates a magnetic surface for the tape to stick to.
Overall, magnetic tape adhesive alone will not bond directly to tile. A magnetic intermediary surface like metal or magnetic primer must be utilized for the magnetic tape to adhere to a tile backsplash or wall.
Conclusion
In summary, magnetic tape will stick well to metallic surfaces like steel, iron, and nickel. It can also adhere to other magnetizable materials like some plastics and woods. However, non-magnetic surfaces like aluminum, glass, tile, and drywall are poor matches for magnetic tape. Fabrics can be hit-or-miss depending on their material composition.
The key factor determining if magnetic tape will stick to a material is whether that material can be magnetized. Ferromagnetic metals with high iron content and some magnetizable plastics and woods allow magnetic fields to pass through them and are readily adhered to by magnetic tape. Non-ferrous materials like glass and aluminum cannot be magnetized, and so magnetic tape does not stick to them.
By understanding the magnetic properties of different surfaces, one can determine if magnetic tape will properly stick to them or not. This allows for informed decisions when selecting surfaces and materials for use with magnetic tape in various applications and projects.