Sandpaper Buying Guide

Sandpaper can be used with power tools and for sanding by hand. A power sander removes material quickly and efficiently. It’s a good choice for getting rid of surface blemishes and for shaping and leveling wood. Power-sanding is also an effective way to prep surfaces for painting. Sandpaper for power-sanding comes in sheets, discs and belts designed to fit specific power tools. Some tools also accept sheets cut to size.

Hand-sanding products give you a lighter touch for woodworking and finishing. You have better control and can sand areas that a power sander can’t reach. With proper technique, the scratches align with the woodgrain and are less visible. Sand wood by hand before applying the final finish and between finish coats. Sandpaper for hand-sanding comes in sheets you cut to size. Some sandpaper can be used for both hand-sanding and power-sanding.

Some papers use natural abrasives:
 

• Garnet is good for hand-sanding. It works well on raw wood, removing light scratches and preparing the surface for finishing. The abrasive particles break during use, providing new edges for removing material, but garnet sandpaper wears quickly.
• Emery works for both hand-sanding and power-sanding metal. Use coarse grits to remove rust or paint and finer grits to polish. Emery cloth sandpaper has a cloth backing.
  

Other abrasives are synthetic:

• Aluminum oxide is a common sandpaper type that works on wood, plastic, metal and drywall. The particles break during sanding, constantly exposing new, sharp edges. Aluminum oxide sandpaper is long lasting, making it a popular choice for power-sanding, and you can also use it for hand-sanding.
• Silicon carbide sandpaper removes material more quickly than aluminum oxide but doesn’t last as long. Use it on wood, plastic and metal for tasks such as rough-sanding, removing paint or rust, and sanding between coats when finishing. Use it on drywall to smooth joints. Silicon carbide products often have a waterproof backing that you can use for wet-sanding, which is a good technique for minimizing scratches when applying liquid to lubricate the work surface. Wet-sanding also helps to prevent the sandpaper from clogging with dust, remove loose abrasive particles and reduce airborne dust.
• Zirconia alumina is suitable for wood, fiberglass, metal and painted surfaces. You’ll find it in the form of belts, pads and discs for power-sanding. Like garnet and aluminum oxide abrasives, the particles break during use, maintaining sharp edges that remove material quickly. Zirconia alumina lasts longer than aluminum oxide.
• Ceramic alumina is available in belts and discs for power-sanding and is good for aggressive material removal on wood. Ceramic abrasives are durable, lasting longer than aluminum oxide.

You may see sandpaper labeled closed coat or open coat. Closed-coat products feature abrasives covering all of the backing. This construction removes more material — making it effective for hand-sanding — but can clog more quickly than open-coat products. Open-coat products have empty space on the backing, giving waste material room to accumulate without reducing performance. Since they don’t clog as quickly, they’re effective for an electric sander.

The grit number of a sanding product indicates the size of the abrasive particles. The lower the number, the larger the abrasive particles; they remove more material but create more-noticeable scratches. A higher number indicates smaller particles, which don’t remove as much material but leave a finer, more polished appearance. Sanding projects generally use several grit sizes, starting with lower-number grits and moving up the scale to finer, higher-number grits. Each higher grit removes scratches from the previous grit, creating an increasingly smooth surface.

There’s a wide range of grit numbers available, from 24 for heavy material removal to 2,000 and beyond for working with automotive finishes. Grit numbers between 60 and 220 will handle most household projects. The specific grit numbers you need vary by project and the material you’re sanding, so follow the abrasive product manufacturer’s recommendations. Here are some general guidelines:

Sandpaper grit numbers from 36 to 100 are good for removing material and work well with power sanders.

Applications include:

• Stripping away finishes, such as paint or varnish
• Removing rust on metals or flaws in wood
• Leveling and shaping wood

Sandpaper grit numbers from 100 to 180 perform well with both hand-sanding and power-sanding, preparing bare surfaces for finishes. Large grit makes a good sandpaper for metal and is used in applications such as:

• Smoothing work pieces
• Removing scratches
• Final preparation for finishing

Grit numbers from 180 to 320 work for finishing. Hand-sanding is good for these applications:

• Removing raised woodgrain fibers
• Scuffing between finish coats

In addition to sandpaper, there are other abrasives, available in a range from coarse to fine:

• Sanding sponges are flexible pads with an integrated grit. They’re effective on both flat and contoured surfaces, and you can use them for wet-sanding or dry-sanding. They’re more durable than sandpaper and are reusable. Sanding sponges with channels built into the surface help keep the abrasive from becoming clogged with dust.
• Steel wool is another abrasive that can conform to the work surface, letting you work on areas sandpaper can’t easily reach. Steel wool can leave behind small strands, which, if left on the work piece, can rust and cause discoloration. Bronze wool is a similar product that doesn’t rust.
• Refinishing or stripping pads are flexible, reusable sheets of abrasive material that won’t shed. You can cut them to a specific size or shape.
• Drywall screens are metal, open-mesh products designed to level joint compound and plaster. Drywall screens don’t clog as easily as drywall sandpaper and can be easily cleaned for reuse.

Common tools for hand-sanding and power-sanding include:

• Hand Sanders and Sanding Blocks: These tools, which use sandpaper sheets cut to size, give you more comfort, control and leverage than sanding with sheets alone and can generate good results on flat surfaces.
• Pole Sanders: Use these for sanding large, flat surfaces such as drywall.
• Orbital Sanders: Also known as sheet or finishing sanders, these handheld power tools use small sheets of sandpaper attached to a rectangular base. The base vibrates in a continuous pattern of small circles. This motion can create a smooth finish but doesn’t remove as much material as other power sanders.
• Detail Sanders: Similar in function to orbital models, these have a triangular or teardrop-shaped sanding base for custom-fit sandpaper to reach tight spaces. Detail sanders are suitable for small areas.
• Random-Orbit Sanders: These handheld power tools use an arbitrary, circular sanding motion to prevent conspicuous marks on the work surface. They remove more material than an orbital sander.
• Handheld Belt Sanders: A rotating band of sandpaper aggressively removes material or shapes wood. They work well on large surfaces and aren’t suitable for more-delicate finishing projects. Poor technique with these sanders can lead to gouges in the work piece. They take more effort to control than other sanders and require two hands to operate.
• Benchtop Belt and Disc Sanders: Use these stationary power tools to sand surfaces for large work pieces.
• Other Devices: Drills, oscillating tools and rotary tools can use bits and accessories designed to handle sanding jobs.