Everyone hates sanding but loves the end result. We know the gorgeous finishes and before-and-after photo sets that inspired us all to get started with woodworking, but the path to success can be a confusing one at times. If you’re new to woodworking and DIY, or just looking to learn a little more about the process, we have you covered.
Before I explain to you the right grit sandpaper for wood, let me briefly explain the two types of sanding that we normally use. If you are already familiar with sanding, then you can jump to the sandpaper grit recommendations.
Manual vs. Powered Wood Sanding
Manual sanding offers the most control over your project and was obviously the norm for the centuries prior to the invention of power tools. However, it’s also time consuming and we do now have power tools, so manual sanding is now more often reserved for small projects, projects that require specific detailing and a light touch, and for finishing touches, as it offers ultimate control in contrast to its corded counterparts.
There are plenty of options for handheld sanding blocks on the shelves of any hardware store, but you can also fabricate your own. You can wrap your sandpaper around wood blocks, rigid foam insulation, a pencil eraser, a piece of plexiglass, or whatever you have in your scrap bin that will work for the project at hand.
The store-bought sanding blocks and tools are also great, though, and their ranks include flexible contour sanding grips that really help to save your fingers on routed edges and intricate moldings.
Nearly every woodworker, DIYer, and even hobby blogger will have a power sander (or two!) in their kits. These tools are best used on flat surfaces, as their powered movement can quickly erode edges or detailed carving.
While there are multiple products and manufacturers in the following two categories and a range of price points, these are the two main options:
Random Orbital Sander
While sometimes “orbital sander” is used as a blanket term, there are actually two different tools to consider here. The random orbital sander spins and also moves back and forth, while an orbital sander only spins. This distinction is important; because the additional back-and-forth motion leaves less of a swirl pattern on the wood and thus, a cleaner finish faster.
Also, sometimes called a pad sander or sheet sander, these tools vibrate and can get into corners or along edges with a bit more control than is offered by the rounded edges of the orbital sander. Their motors are typically slightly smaller than the orbital sanders, and are thus better for lighter-duty projects rather than heavy stripping. This also makes them slightly less expensive, so if you’re buying rather than renting or borrowing the tool, this may help you decide between the two.
Grit for Sanding Bare Wood
Tabletop DIYs are an ever-growing trend, especially with an emphasis on reclaimed materials. Every single home needs some kind of table, desk, or other work surfaces- it’s a universal need anywhere in the world.
Depending on how raw or unfinished the wood is, you may want to plane it first, or bring it to a shop where it can be planed for you. This will provide you with a more uniform and level surface to begin your own finishing process. For a professional-level smoothly sanded finish for your tabletop, we recommend patient, diligent passes with gradually increasing fineness.
Start with one pass with a coarse grit sandpaper like 40 or 60 grit to shape away any gouges and smooth any bumps. Then move to an 80-grit sandpaper, then 100-grit sandpaper, then 120-grit sandpaper. In our article on sandpaper grits, we discuss how this process is often referred to by tradesfolk as “going through the grits.
After the 120 grit pass, you may want to vacuum or dust the surface before moving on to ensure your sanding pad doesn’t get clogged up. Follow with a 150-grit pass, a 180-grit pass, and a 220-grit pass. Dust or sand again, and then finish with a 320-grit pass.
This last pass can be powered or by hand, though you’ll have much more control with a manual sander. Of course, depending on your work, you may not even require this fine-grade sanding step.
While 320 grit is considered extra fine and is a commonly accepted finishing grit, this might not always be necessary, depending on the project. If your end goal is to stain a frequently-handled surface, a finer finish is absolutely worth the extra effort.
However, if, for example, you’re staining a baseboard or some wall paneling, a few imperfections aren’t a dealbreaker. Rather, it’s more important to ensure the stain absorbs uniformly throughout. Different woods have different hardnesses and, thus, absorbencies. So do a little homework on the recommended sanding grit for staining that particular type of wood.
Generally, though, most wood is suitable for staining between 180 grit and 220 grit.
If the wood will be painted rather than stained, it isn’t as critical to achieve flawless smoothness, as much as it is to ensure the paint has a porous surface to adhere to. Some factory-cut wood has a light glaze on the surface, so a few passes with 120-grit to 150-grit sandpaper before priming or painting can both smooth it over and also open it up. Paint is somewhat self-leveling after a coat or two, so subsequent sanding passes with a finer grit aren’t really necessary.
Outdoor decking also trends toward a lower sanding grit prior to finishing for the same reason. Decks are usually made with pressure treated wood and are thus coated. In order for the stain or paint to really penetrate into and properly seal the wood, it’s recommended to sand with a 20-50 grit sandpaper on the first pass and 60-80 grit sandpaper on the second.
For interior hardwood floors, depending on the type of wood, how old the floors are, and how long it’s been since they were last sanded, it’s recommended to start around 24 grit to 36 grit, and work up to 80 or 100 grit before staining or resealing.
If you aren’t starting from scratch and are rather refinishing wood to give it a fresh look, the approach can be slightly different from raw wood.
While there are a few different ways to remove or strip paint from wood (including heat and chemical processes), if sanding, 80 grit is a good place to start.
Once most of the paint has been removed from the flat surfaces with a power sander, start to refine the surface by working your way up the grits.
If you’re just removing a previous stain or varnish, start with 120-150 grit and work up to 220 grit before restaining.
If you’re refinishing furniture, the sandpaper grit really just depends on the type of furniture and the type of wood. 120-150 grit is a good place to start, and your intended finish will determine how fine to sand the surface. If part of the surface is being painted, there’s not much need to sand finer than 150 grit. If your design includes part stain part paint, you will likely want to ensure a smoother finish on the surfaces being stained, but not extend that energy to the areas that will be painted.
Tips and Tricks
- Sanding Direction: Always sand in the direction of the grain. If you sand with a low grit against the grain, you will likely create new gouges in the surface, and gouges that go against the grain are very hard to smooth away. For your own sanity, always stay with the grain.
- Sanding against the grain removes material faster, as does sanding with low grit sandpaper. Keep this in mind on those first few passes to ensure you don’t take away more than you intended to.
- Sanding Pressure: Keep your pressure light when using a power sander. This will reduce sanding marks on the surface and prolong the life of the sandpaper sheet or disc. If you find yourself pushing harder to get results, the sheet has probably worn down, so just switch it out instead of wearing yourself out.
- Sandpaper for End Grain: On the end grain, go a step finer than the surface sanding grit. This will reduce the absorbency of the stain and thus provide a more aesthetically pleasing uniformity with the rest of the piece.
- Mineral Spirit Trick: Some tradesfolk recommend using mineral spirits on the surface of the wood to see if your sanding has reached the desired finish. Before evaporating, the spirits will highlight any remaining scratches on the surface that might not otherwise be visible.
- Use PPE: Protect your lungs, eyes, and ears when sanding with appropriate PPE, and always ventilate any area where you’re using chemical processes (including paint and stain).