Sanding is a skill I often use as a professional carpenter and woodworker, but the variety of sandpaper types, grit numbers, sizes, and materials can be overwhelming at first. In this guide, I’ll give you an overview of three basic types of sandpaper, how to use them, and how to choose the right sandpaper for your job.
New to sanding? Watch the video below for a quick intro to choosing the correct sandpaper grade for your project. Then, keep reading to learn more.
Sandpaper Grades
The term people most commonly hear associated with sandpaper is grit, which indicates the size of the abrasive particles on the paper, i.e. the coarseness of the sandpaper. A lower grit indicates larger, coarser abrasive grains, while a higher grit denotes finer abrasive grains. Some common grades:
- 40 to 120 grit: Extra coarse and coarse sandpaper used for quick stock removal and leveling. Used with power tools like belt sanders, this grit level can lightly sculpt wood.
- 120 to 240 grit: Medium sandpaper used for smoothing between coats of finish and stripping old finishes‌. It is a go-to grit for orbital and reciprocating hand sanders.
- 240 and up grit: Fine and extra-fine sandpaper used to get a smooth feel before applying wood finish.
Matching the sandpaper grade to your purpose is important to avoid issues like deep scratches or a rough surface.
Test grits to avoid raising the grain. The ideal grit depends on the wood species you work with. Always test sandpaper on a scrap piece first. Starting with grit that is too coarse risks tearing fibers and scratching the wood, especially if you accidentally sand perpendicular to the grain. Begin with medium grits (around 150), then use more coarse grits as needed.
Sanding Different Wood Types
When sanding different types of wood, it’s important to consider the unique properties of each material. Proper work techniques for a given wood will help avoid problems like scratches, tearing, and an uneven surface. Some tips:
- Softwoods, like pine, scratch easily. Use 240-grit or higher for final smoothing.
- Hardwoods like oak are more scratch-resistant and can handle more coarse sandpaper.
- Exotic woods with interlocking grain, such as teak, can tear if sanded improperly. Start using a lighter sandpaper than you think you need.
Sanding by Hand Vs. Machine
Hand sanding with sandpaper sheets lets you smooth contoured or detailed pieces that are difficult to reach with a power sander.
Work systematically with the wood grain, applying smooth, even pressure.
Belt sanders, orbital sanders, and other power sanders make quick work of sanding large, flat surfaces like tabletops. Be careful, though. Their speed and persistent action can damage wood in a hurry. Ensure you have the right sandpaper for the job, and avoid lingering in one spot.
With both, you’ll likely have to move through different grits of sandpaper to take the wood from where it started to where you need it to be. Conveniently, manufacturers sell packs of sandpaper with various grits and grades. Shop your local hardware store.
When to Sand Wood
Sanding is often the final step after you assemble your project, though you can do it as you go. I recommend a final sanding after the project is put together.
- Sand raw wood to prepare and smooth the surface before applying stains, paint, varnish, or other coatings.
- Sand between coats of paint to help the next coat bond. Sometimes, you should use a wet sanding technique, where water is applied to the surface while you sand. That increases sanding performance and minimizes potentially hazardous dust.
- Sand to remove old finishes before recoating.
- Sand out dents, scratches, and imperfections in a finish, using finer paper to blend the repair.
- Sand any areas with splinters.
Preventing Damage When Sanding
Using a careful sanding technique prevents imperfections and wood damage. Follow these guidelines when sanding by hand or machine for the best results:
- Work systematically along the wood grain.
- Apply smooth, consistent pressure over the surface.
- Start with medium grits (around 150) and use coarser paper if needed.
- Always sand in the direction of the wood grain, never across it. This technique is less essential for fine-grit sandpaper, but it’s always good advice to follow.
- Move to increasingly finer grits to get a polished finish.
- Clean clogged sandpaper with a brush to increase longevity and ensure the best performance.
Is Sanding Wood Difficult?
Sanding wood is not difficult. It is one of the easiest woodworking skills to master. DIY sanding and finishing projects are perfect for beginners.
If there’s only one essential rule to follow: sand with the wood grain (and not against it) with heavy-grit sandpaper. Other than that, it’s hard to mess up a wood sanding project.
If you mess up, don’t worry. The great thing about sanding is that you can sand out your mistakes.
FAQs About Sanding Wood
Can I Use a Power Sander on All Wood Types?
Yes, but match the sandpaper grade to the wood. Finer paper, around 220 grit, is safer for softwoods. Hardwoods can handle more aggressive sanding from belt sanders.
How Do I Choose the First Sandpaper Grit to Use?
Choose 120 to 150 grit sandpaper to start on raw wood, and work up to 220 or finer grits for smooth finishing. To remove old finish, begin with 80–100 grit, then switch to finer grits.
How Can I Avoid Swirl Marks When Sanding?
Move the sander straight up and down the grain, overlapping paths. Apply steady, even pressure and avoid rocking or circular motions.
Can Sanding Damage Wood?
It depends on the damage. You can’t sand away certain types of damage, such as rot. You may also need a different solution for stained woods. However, you can certainly sand out for light surface damage.
When Should I Replace Worn Sandpaper?
You should replace it when it’s compacted with material and no longer abrasive. You’ll often go through multiple pieces of sandpaper during a sanding project.