If you follow us here on Obsessed Woodworking, you know we often repeat the mantra: “The right tool for the right job.” If you follow this simple rule, you’ll never go wrong in the shop.
Virtually every project you will work on in your shop involves at some point the removal of material – – cutting, sanding, planing, filing – – something to shape or smooth a piece of wood.
One such tool is a rasp plane, a hand plane of sorts that sometimes will be the right tool for the job.
What Is a Rasp Plane?
When you need to remove material from a soft material like wood, plastics, laminates, fiberglass, even horse hooves, and leather, it’s the rasp plane you’ll reach for often. The very rough cut of a rasp plane gets the job done quickly and can then be followed by some other tool to smooth out those cuts.
More appropriately called a rasp-cut file, this tool in the woodworking shop, cousin to the file, has rows of individually cut teeth that are produced by a punch-type chisel. In fact, the rows of these teeth across the rounded blade look like mini-chisels.
It’s a bit of a bull in a china shop tool that removes material quickly and coarsely. They are the perfect hand tool when trimming and shaping timber when you are creating a curved or rounded edge. This coarse cutting is then followed up by finer tools that will smooth out the wood as you move it along to a finished surface.
In the advancement of taking a piece of lumber along to the finished piece, the rasp plane shows up on the list early in the process, roughing out a curve or rounded edge, shaping it for those finer tools, and eventually sandpaper, as the project is readied for the chosen finish.
How Does a Rasp Plane Work?
Among the options of hand planes, and as you’ve learned, the rasp plane is the rough cousin. The individually cut, or more properly, punched teeth are aligned in rows across the blade.
As with other planes, grasping the handle and applying a small amount of pressure at the front end, it is run along the wood grain. No pressure should be applied in the drawing back of the rasp plane for the next pass on the wood so as not to dull the teeth.
The sharp teeth will do most of the work, while your pressure hand simply maintains contact between the teeth and the wood. The greater the pressure, the greater amount of material will be removed. When creating a curved or rounded surface, both greater and lesser pressure will be used to create the desired shape.
Rasps come in various sizes, and their abrasive blades come in a variety of abrasion abilities. Again, the right tool for the right job – what is the material being removed, and how much is coming off.
In an earlier piece here, we discussed the tools a beginner should have in the shop. You’ll find that piece here. We included a jack plane or a block plane as one such tool. Perhaps we might consider adding a rasp plane to the list, depending on what types of projects are to be tackled.
A jack plane will also remove a lot of material in a single pass, but not as coarsely as a rasp plane will; and, a block plane is the better choice for tighter work in creating smooth finishes in joints. Yet, as you are now learning, a rasp plane has its advantages in the early stages of a project to rough out wood quickly into shape.
Various Models of Rasp Planes
Rasp pocket planes and surform planes are among the models of rasp planes that can come in handy at times in the shop.
Think cheese grater when you think of surform planes. It’s a surface-forming tool (thus sur + form = surform) that comes in the shape of a plane. The “pocket” in rasp pocket planes refers to size rather than purpose or function – they are smaller, pocket-sized.
It’s the same perforated sheet metal with punched, chisel-like teeth that will remove material quickly from the wood piece. Surform planes are a cross between a plain rasp and a rasp plane – a little play on words, but it describes a surform well. A plan rasp is file-like; a rasp plane is plane-like, and a surform plane is a rasp plane-like tool.
We found some videos to help distinguish surform planes (pocket-sized) from other planes and rasps and files. You’ll understand better when you see them in action.
You’ll find one video here:
Finally, a good video on planes in general: how to use a hand plane
While often used on bullnose work, rounding off edges and corners, they can also be used to remove material from a door that is sticking, for instance. The material being removed will extrude through the holes of the blade as the chisel-like teeth dig it out.
What is the Difference Between a Rasp and a File?
As we’ve seen now, a rasp is a coarse variation of a file used to remove material quickly in the early stages of shaping wood in a project. While a file will also shape and trim, it does so to a much lesser extent, smoothing more than shaping, and is a kinder, gentler tool.
Each plays a part in your project between the rough cut of a saw, power or hand, and the smoothing and finishing of the wood by sandpaper. Neither is a replacement for smoothing and finishing, the ‘tweener tool if you will.
Both a rasp and a file can play an essential role in the process of your project, and each brings with them their own specialty. Cut – rasp – file – sand – stain or paint. Add each to your set of shop tools if your projects are likely to require those special talents.