Choosing the most appropriate wood smoothing tool will help you achieve superior results.
When it comes to smoothing wood, choosing the best tool for the job is the first step in getting the results you want. The main wood smoothing tools at your disposal are sandpaper, scrapers, planes, rasps and files. Each has its advantages.
Sandpaper: For slow but effective smoothing, with dust as a downside
Sandpaper, the most basic tool for smoothing wood, contains tiny particles that scrape away imperfections and scratches. One advantage to using sandpaper is that it requires little finesse (unless you’re using a power sander) and therefore little practice.
You’ll need to start with a coarser grit and work through finer and finer grits to remove the scratches and imperfections the previous grit left behind. Skip a grit and you may see flaws. How fine a grit you end with depends on your project and the wood you’re working with.
Different sandpapers use different abrasive materials. Aluminum oxide is durable and often used for sanding wood. For a particularly smooth finish on bare wood, garnet sandpaper may work best.
One downside to sanding wood: It creates dust, which you don’t want to inhale. Wear appropriate respiratory protection, especially when operating powered sanding equipment. The dust can also “clog” the sandpaper. Open coat sandpaper has more spaces between the particles and is slower to become clogged. Closed coat sandpaper is the most common.
Scraper: For fast smoothing and superior flatness
Need a tool to shave wood? A hand scraper, also known as a card scraper, slices off very fine wood shavings, smoothing wood faster than sandpaper and achieving superior flatness. It’s nothing more than a thin piece of steel, usually rectangular, with a sharpened edge, or blade. A cabinet scraper is a hand scraper mounted in a frame, with screws for adjusting the blade.
Pushing or pulling the blade at an angle leaves a perfect, smooth finish and no scratches or dust. If you’re planning to stain or vanish the wood, using a scraper or planer may produce more clarity and contrast than using sandpaper.
Conventional wisdom calls for using scrapers on hardwoods only, though some people use them on softwoods, too.
A scraper is dirt cheap compared with other options (unlike sandpaper, you buy it only once), but be prepared to put some elbow grease into the job — scraping can be tiresome. The key to using a scraper effectively is sharpening and honing the blade and then creating a “burr,” a minuscule lip or hook at the edge of the sharpened steel that becomes the cutting edge and makes smoothing wood easier. One way to create the burr is with a tool called a burnisher, as this video about how to sharpen and use a scraper explains.
Scrapers tend to lose their edge quickly, so be prepared to re-sharpen and re-burnish as necessary. When the shavings left behind become more like dust, it’s high time.
Plane: For ultimate smoothing, shaving and leveling
More expensive than a scraper, a hand plane can be used as a tool to flatten wood. It can also make wood perfectly smooth and shave down stubborn cabinet drawers and door frames. Pushing the plane creates wood shavings at the back of the tool.
One key to using a plane successfully is starting with a finely sharpened blade. Some planes have adjustable blades. Until you know how deep you can cut without tearing the grain, start with a shallow blade angle and gradually increase the angle as necessary.
This video from Ask This Old House shows you how to grip and use a plane with good results and explains what hand planes of different sizes are used for.
Power planers can get the job done faster, but they’re not appropriate for all tasks, and many experts agree it’s a good idea to master the hand tool first before graduating to a power tool.
Rasp: For shaping curved wooden surfaces
A rasp is often confused with a file, but this hardened steel tool has course, individual teeth that rise up like tiny mountains. It is a tool for smoothing wood and wood only.
The teeth cut wood without ripping up the surface, and they don’t clog easily. A rasp is a good choice for shaping a table leg or other curved wooden surface. It will leave a rougher surface than a file. Use it to shape the wood, then use a file to finish the job, just as you would use increasingly fine grits of sandpaper to smooth a surface.
For rasps, the smoothest grade is bastard, followed by cabinet (also called medium) and wood, which is the coarsest grade.
File: Meant for metal but also useful for woodworking
A file is a hardened steel tool for removing fine amounts of material, including metal, wood or plastic. Files come in different sizes and profiles and can be used for a variety of tasks. For example, one type of file can be used to sharpen a lawn mower blade or a metal woodworking tool while another file can be used to smooth curved or contoured wood.
A file has closely spaced grooves that run the width of the file. Straight-cut files have grooves that run parallel to each other, while cross-cut or double-cut files have groves with opposing angles. A file’s cutting ability depends on the cut of these grooves. There are several grades of cutting action, including smooth, second cut (also called medium) and bastard cut, the coarsest grade.
The grooves on a file clog up easily, so it’s best to use a file in conjunction with a rasp.