Rasps

Rasps

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Even though rasps closely resemble files, they're very different beasts. Instead of single rows of teeth cut into the metal surface at an angle, rasps have tiny individual teeth in parallel rows. And unlike the smooth, almost planing action of a file, a rasp is designed to virtually tear out chucks of wood. This makes them very aggressive, and a rasp in the hands of a seasoned user can remove a lot of material in no time flat. That's why rasps are reserved solely for roughing-out work that will eventually be smoothed with files, scrapers, or sandpaper.

Most rasps are around 8" to 12" long and come in coarse, bastard, second-cut, and smooth grades. You may also see them described as either a wood rasp, a cabinet rasp, or a patternmaker's rasp. Wood rasps are the most aggressive of these and usually come with a bastard cut in either flat or half-round profiles. Cabinet rasps are typically second-cut or smooth and also come in half-round and flat (halfround being the more common). Patternmaker's rasps are also available in secondcut and smooth, and they generally have smaller teeth that tend to leave a smoother finish than the cabinet rasp.

One of my favorite rasps is a 4-in-hand rasp (originally called a shoe rasp). This handy tool combines four tools in one, as you'd guess from the name. Its doubled-ended with a half-round shape. One end is a rasp, the other a file—youd think they'd call it a 4-in-hand rasp/file. Effectively, you have a half-round file, a flat file, a half-round rasp, and a flat rasp. What I like best about this tool is that both edges are "safe," or smooth. This makes the 4-in-hand rasp particularly useful when rounding-over tenons to fit into rounded-end mortises, like those cut by a router.

I also like how the shorter body fits nicely into my hand—and my shop apron pocket, too. My only use for this tool is light work, like fitting a joint or rounding-over tenons. If I have a lot of wood to remove or I'm working on a long or large surface, I'll pull out the appropriate standard-length file or rasp, since the short body of the 4-in-hand is inadequate for this type of work.

FILECARDS

Files and rasps require a lot of maintenance—a lot more than some woodworkers give them. No wonder the tool skips over the surface instead of cutting properly. Most often it just needs to be cleaned, and you should do this after every half-dozen strokes or so. I know a lot of folks who've never cleaned their files. The problem is, the tiny teeth of a file quickly fill with waste. If you don't remove it, the file can't work properly. Here's where a filecard comes into play. Filecards typically have two faces: a nylon brush on one face and a wire brush on the other. Start with the nylon brush, and if this doesn't clean the file, flip it over and use the wire side. Stubborn bits can be removed with the steel pick that's commonly built into most filecards.

Speciality Files

Speciality Files

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Taper files

Taper-cut files are triangular-shaped files that taper along their length. They come in various sizes that are defined by their cross section and taper, not by their coarseness. Common sizes are regular, slim, extra slim, and double-extra slim. These files are most often used for sharpening saws but can be pressed into service for other tasks as well.

Needle files

Needle files (sometimes called jeweler's files) are thin, delicate files that are used for small fine detail work. They're usually sold in sets that include a variety of shapes, including round (often called a rat-tail file), square, rectangular, half-round, triangular, and flat. I use my needle files frequently to smooth tiny details, enlarge a hinge hole, and in the past, to sharpen spurs on some of my drill bits; this task has since been taken over by my diamond hones (see Rasp Planes).

Riflers

Riflers are specialty files used primarily by carvers to smooth out small details in their work. They may be double-ended or come with a handle. Riflers are available individually or in sets and can be either files or rasps. I bought a set years ago when I first became interested in carving. Although I don't do a lot of carving anymore, I occasionally pull them out when I just can't get into a spot with any other tool. They really are quite handy.

Mill Files

Mill Files

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There are three common techniques for using a file: straight, cross-filing, and drawfiling. Each has advantages and disadvantages.

Straight

Straight or in-line filing is not used often, since most files perform best when skewed at an angle (see Cross-filing, below). There are times when in-line filing is your only option or actually works best for the job. When I prepare the edge of a scraper by filing it flat, I typically use the in-line method, since this helps to create an absolutely flat edge. If you hold the file at an angle, there's a big tendency to tip or rock the file, which will produce an angled cut.

Cross-filing

Cross-filing is the most common technique used with both files and rasps. With this method, the file is skewed at an angle to produce more of a shearing cut. Cross-filing lets you quickly remove wood while leaving a fairly smooth surface. Any roughness can usually be removed with draw-filing (see below), a scraper, or sanding.

Draw-filing

Draw-filing puts the smoothest finish you can get on a surface with a file. The file is held at 90 degrees to the edge and is drawn across the surface. This technique works best with single-cut files and with a light touch. As with any filing operation, make sure to lift the file at the end of the stroke and return it to the starting position.

It's amazingly easy to destroy hours (even days) of work with one careless slip of a file. Since these beasts are all-metal, they can and will scratch, ding, and mar wood surfaces if allowed. Here's a tip that can save you a lot of aggravation when filing, particularly near surfaces that are easily damaged, such as plywood and veneered panels: Simply wrap a turn or two of masking or duct tape around the end of the file. This way you can safely rub the file on your surface without risk of damage.

FILE HANDLES

It's odd: Although almost every file manufacturer warns you not to use their files without a handle, none of them supply one. It's sort of like buying a table saw that doesn't come with a blade guard; go figure. The point is, you really should use a handle when using a file, because the tang is a rather nasty bit of work. It's sharp, often covered with burrs, and generally painful to hold in your hand. I admit that some of my files don't have handles, but I have taken the time to remove any burrs and soften the edges.

My example notwithstanding, it's a good idea to fit every file and rasp that you own with its own handle. These can be bought for little at most hardware stores, or you can easily make your own. If you're a turner, you can get fancy (drawing below).

Otherwise, a short length of dowel will do—anything is better than nothing. NOTE: To prevent the handle from splitting, it's a good idea to add a metal ferrule; a short length of brass or copper pipe works great for this.

File And Rasp Terminology

File And Rasp Terminology

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How often you use files and rasps will depend heavily on the type of work you do and how long you've been woodworking. If your work involves a lot of curved shapes, your files and rasps are likely very prominent in your tool cabinet. Folks who build antique reproductions, especially Queen Anne furniture, with its classic S-shaped cabriole legs, use files and rasps regularly. On the other hand, if you build Craftsmanstyle furniture, with its rectilinear lines, you probably use them less.

How long you've been woodworking is also a factor. I used files and rasps much more often when I was a novice than I do now. This was partly because I didn't have as many tools then, and also that I've since learned better ways to do the jobs. Now, for example, instead of trying to fit a tenon into a mortise by filing it, I use a shoulder plane or a chisel. And instead of shaping a curve on a leg with a file, I tend to use a spokeshave. Any of these tools leaves a cleaner, smoother surface than a file or rasp and, just as important, is more of a pleasure for me to use. I still use my rasps and files—just not as often.

File cuts

Files are made by cutting parallel rows of teeth into the surface of the metal at an angle (usually between 60 and 80 degrees). There are three common "cuts available: single cut, double cut, and curved tooth (right drawing). Single-cut files are the most common and work well for both general-purpose woodworking and the occasional metalworking I need to do around the shop. Double-cut files have a second set of teeth at an opposite angle to the first set; so they're more aggressive and work great when you need to remove a lot of material in a hurry. Curved-tooth files are becoming quite rare and are very aggressive. These have been replaced primarily by the rasp (see Rasp).

Shapes

Files come in a huge variety of shapes and sizes. The most frequent shapes you'll find are: mill (or flat), half-round, round, 4-in-hand, and triangular (right drawing). For all-around woodworking, the halfround shape is your best bet. This combination of a gently curving face with a flat face will handle most jobs. Lengths for files vary from 4" to 12" and larger. Eight-inch and 10" files are the most suitable for the shop, while smaller files, particularly taper or triangular files, are useful for sharpening.

Carving Tools

Carving Tools

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The first time I seriously began shopping for carving tools, I couldn't help snickering at some of the names: Fluteroni, spoon bit, allongee fishtail? Silly though they may sound, these names have special meaning to carvers, and often aptly describe the business end of the tool. Carving tools can be broadly categorized into three main groups: gouges, chisels, and specialty tools. Each tool is designed to handle a specific task; serious carvers can have dozens of carving tools, ranging from delicate 4"-long detail chisels to huge gouges for roughing-out work.

Standard sizes

Unlike most woodworking tools, carving tools have long been available in standard sizes (drawing below). If one carver tells another that he used a No. 8 gouge, the other will know exactly which tool he used. Surprisingly, most toolmakers follow these standards. Not all do, however, so stick with a reputable brand when you buy.

Gouges

A carving gouge is basically a chisel that's curved across the width of the blade (right photo). Of all the carving tools, you'll find that gouges have the widest array of curves, sizes, and special features (such as a bent neck). In general, gouges may be one of two types: in-cannel or outcannel. With an in-cannel gouge, the bevel is ground on the inside of the blade; an out-cannel gouge has its bevel ground on the outside. Out-cannel gouges are by far the more popular.

Chisels

Although some carving chisels often look similar to standard firmer chisels, there's one big difference: Instead of the bevel being ground on one side, the bevel on a carving chisel is ground on both sides so it'll meet in the center (right photo). Unlike the concave (hollow) grind of most chisels, a carving chisel generally has a convex grind. This helps prevent the edge from digging in too deep in use. Carving chisels may have either a square edge or a skewed edge.

Specialty tools

In addition to gouges and chisels, the carver typically has a number of other specialty tools in his arsenal (right photo). Parting tools and veiners are the standbys. The most commonly used parting tool is the V-shaped version used for cutting grooves in wood and making squarecornered cuts. The V-parting tool is widely used for incising letters in signs. Veiners can have square or rounded edges and are used mainly to add decorative grooves or "veins" in carvings.