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Choosing the right sandpaper for your D.I.Y. project is key to achieving a smooth, clean finish.
Whether you're upcycling furniture, preparing to paint, or sanding a deck, selecting the correct sandpaper type and grit can make all the difference to a successful job.
What is the difference between sandpaper grits?
Sandpaper comes in different grits, which refers to the coarseness of the abrasive material. A lower grit number, such as 40 or 60, represents a rougher, coarser paper. Higher numbers, such as 120, 240, or 400, indicate finer abrasives for smoothing surfaces.
Coarse grit (40-60) is used for heavy sanding tasks such as removing old paint, rust or sanding very rough surfaces. It’s also helpful for sanding down wood that has been heavily damaged or for stripping materials quickly. However, it can leave deep scratches, so it should be followed by a finer grit for smoothing.
Medium grit (80-120) is suitable for general sanding purposes, like smoothing rough surfaces or preparing wood for finishing. It provides a balance between abrasiveness and smoothness and is commonly used for tasks like sanding plasterboard or wood before painting.
Fine grit (150-180) sandpaper is ideal for smoothing the surface after sanding with a medium grit sandpaper. It’s often used for finishing touches on woodwork, especially when preparing a surface for painting or staining.
Very fine grit (220 and above) is used for the final sanding stage, helping to produce a smooth, flawless finish. It’s ideal for sanding between coats of paint or varnish to create an ultra-smooth surface.
What sandpaper type to choose?
Sandpaper is available in various forms, each designed for different uses. The form you choose will depend on your sanding technique and the tool you’re using.
Sandpaper sheets are the most common and versatile type. They are typically used by hand or with a block sander. The sheets can be easily cut to size and are ideal for smaller projects or areas that require more control.
Sandpaper rolls are great for larger projects where you need to cover more surface area. Rolls can be cut to size or wrapped around a sanding block for use with power sanders.
Sandpaper discs and belts are specifically designed for use with power sanders. Discs are commonly used with orbital sanders, while belts are used with belt sanders for faster, more aggressive sanding.
Sanding sponges are ideal for precision work, such as sanding around edges or mouldings. They can also be used wet or dry, making them versatile for different materials and finishes.
How to match sandpaper to your material
Sanding different materials require different types of sandpaper to achieve the best results. The material you are working with will determine the type of abrasive and backing material you should choose.
For wood, choose sandpaper with a garnet or aluminium oxide abrasive. Garnet is ideal for softer woods, while aluminium oxide is more durable and works well on hardwoods. Start with a coarser grit (80-100) to smooth rough surfaces, then progress to finer grits for a smooth finish.
Metal surfaces require sandpaper with a silicon carbide abrasive, which is sharp enough to remove rust and corrosion. Start with a medium grit (80-120) to remove the rough material, then switch to finer grits (220 or higher) to polish the surface.
For plaster, you’ll want to use sandpaper with a fine grit, typically in the range of 120 to 180. Plaster sanding can produce a lot of dust, so opt for a sanding sponge or use a sander with dust extraction and a filter.
When sanding painted surfaces, it’s essential to use a fine grit sandpaper to avoid removing too much paint. Start with 120-grit paper and finish with 220-grit for a smooth, even surface.
What sandpaper backing material to choose?
The backing material refers to the substance that holds the abrasive particles in place. It can affect the durability and flexibility of the sandpaper.
Paper-backed sandpaper is typically used for light-duty tasks, such as sanding wood and finishing work. It’s easy to use but can tear more easily than other backings.
Cloth-backed sandpaper is more durable and flexible, making it suitable for heavy-duty applications, such as sanding metal or automotive work. It’s resistant to tearing and can be used for longer periods of time.
Sanding sponges are ideal for contours, edges, and areas where flexibility is needed. They are particularly useful for sanding plasterboard, corners or curved surfaces.
The type of sander you’re using will also influence your sandpaper choice. There are several types of sanders, including orbital sanders, belt sanders and detail sanders. Each requires specific sandpaper shapes and sizes. For example, orbital sanders typically use round discs, while belt sanders require long, continuous strips of sandpaper.
How to keep safe when sanding
Always prioritise your safety when sanding. Wear a dust mask with a suitable rating to protect your lungs from harmful dust particles. Safety eyewear is also vital to shield your eyes from flying debris.
Be aware that older properties can contain asbestos, which can be hazardous if disturbed. Never sand any material that could contain asbestos, as inhaling the fibres can lead to serious health issues. If you’re unsure whether your property contains asbestos, it's important to have it professionally assessed.
How to choose the right sander for the job
For more helpful information, check out our guide How to choose the right sander for the job.
