Sunday, January 17, 2010

More Chisels Than You Can Shake a Stick At...

I recently was asked to teach a hand-tool class for the Gwinnett Woodworking Association, my local woodworking club - I choose to focus on Chisels, Gouges and Draw Knives (that last I justified purely to the form of a Draw-knife, resembling a chisel with a handle on either end, sharpened along the end). To prepare, I gathered up what I had that qualified in those categories - it's funny how you accumulate things. I didn't realize I had so many - I'm not even sure this is everything, as I'm sure I have some stuffed away in boxes.












In case you're wondering, here's the lesson plan:

Wood Chisels, Gouges and Draw Knives

What are these and how are they used?
These are bladed, cutting or shaping tools, usually with an extended handle for striking or leverage for prying. They are used to shape wood by removing material. They’re primarily used during the fitment of wood parts into project components, or for decorative carving.

What is a Wood Chisel?
Wood Chisels are hand tools used to shave or chip wood. Wood Chisels can be operated by striking them with a hammer with some care. There are two main types of wood chisels – those used by carpenters and those used by woodworkers.

Carpenter chisels are broken into types by size and usage:

• A butt chisel has a short blade that ranges from about 2 1/2" to 3" long. It is used by pattern-makers, cabinetmakers, carpenters and do-it-yourselfers for carving, paring and similar work. It can be used with hard-faced hammers. These usually have tang handles and often have metal plates on the end to aid in striking with a hammer. Butt chisels generally have 30-degree bevels.

• The firmer chisel usually 3 ½” to 6” and is meant to be lightly stuck or used for hand work. .which is used mainly for cutting deeply into wood. It should be used with soft-faced hammers or with hand pressure alone. Firmer chisels are usually the same length as bench chisels (see below) but of thicker, heavier steel, usually straight sided. For paring and striking with 30-degree bevels and socket handles.

• Stanley also had a chisel that fit between the butt and firmer that they called a pocket chisel – it had a 4 ½” blade with their firmer chisel at 6” – these also have a 30-degree bevel.

• Framing Chisels are larger, longer chisels usually an inch or larger wide. Some were designed for paring with beveled edges and 20-25 degree bevels and some for striking with square edges and 30-degree bevels. Framing chisels usually have hooped, socket handles.

  • Framing corner chisels are framers forged into a 90-degree angle to clean out corners. Generally 30-degree bevels. Usually with hooped, socket handles. 
  • Millwright or Factory mortise chisels are very long, very heavy mortise chisel designed for heavy striking with heavy, hooped handles. Many were 16” long and often made by manufacturers like New Haven Edge Tool who specialized in large chisels. Always with hooped, socket handles and a 35-40 degree bevel.
• English “Pigsticker” mortise chisel is a short, stubby, fit-in-the-tool-chest, tang-handled mortise chisel with un-hooped handle designed for striking with 35-40 degree bevels.

• Slicks are large, very heavy 2-4” framing chisels with long handles up to 24” designed for paring large timbers with 20-25 degree bevels. Never struck. Always with socket handles.

Woodworking chisels are broken up into types by usage:

• A bench chisel has a longer blade, usually 3 ½” to 6” and is meant for workbench use, lightly stuck or used for hand work. It generally has a 30 degree bevel and beveled edges.

• Paring chisels are long, thinner chisels not designed for any striking, only paring with 20-25 degree bevels. Some have "cranked" handles for clearance and were primarily used by pattern makers making negative patterns in soft pine. Others are skew cut to reach into corners, and a “dovetail” chisel is diamond-shaped to clean female sliding dovetail sockets. Paring chisels usually have tang handles.
  • Cranked Paring Chisel – the blade is offset so the handle is above the surface of the work. These are mostly used by pattern makers to get into areas that are below the surface of the work piece.
  • Skew Paring Chisel: has a 60 degree cutting angle and is used for trimming and finishing.
  • Dovetail Paring Chisel – these have nearly a diamond shape to clean female sliding dovetail sockets. 
• Sash Mortise Chisel is a medium length mortise chisel for bench use, generally with un-hooped handles. “Sash” comes from window factories, and there is some confusion describing medium length and long length mortise chisels as factories generally used the longer chisels but the medium ones are often called “sash” chisels.

Blade types are generally divided into registered and beveled.

• Registered Chisels have sides that are square to the back – the extra metal provides more blade strength for really tough jobs where the handle is struck to remove large chunks of wood

• Beveled Chisels – have sides that are beveled to make it easier to fit the chisel into corners. These days the beveled chisel is much more common than the registered chisel.

Chisels have wood or plastic handles. Wood handles are available in both tang (the end of the blade or tang fits into the handle and is reinforced with a metal ferrule) and socket type (a projection from the handle fits into a socket in the blade). Plastic handles fit only tang construction.

Quality woodworking chisels have large, ergonomically shaped handles for a comfortable, sure grip and better control. Blades should be of high-quality carbon, heat-treated steel with precision ground cutting edge. In addition, carpentry chisels should have crowned steel strike caps to help center the blow (why these are often called “pounding” chisels).

Japanese Chisels

 The better quality Japanese wood chisels are made from laminated steel. There are different types of metals used in each chisel. The better ones are laminated by hand, over a charcoal fire. The combination of the metals makes a chisel that takes a very sharp edge, and is hard enough to maintain the edge for a long time. This technique produces a tool that have a harder edge, usually a hardness rating of Rockwell 64, compared to their western counterparts of around 62 on the Rockwell scale. There are two basic metals used in these chisels, white steel and blue steel. The names come from the color of the paper the steels are wrapped in. White and blue steel come in various grades that vary in carbon content. Both have low levels of impurities. White steel is a simple carbon steel. Blue steel contains alloying elements, and sacrifices some sharpness for edge retention, toughness, and corrosion resistance, although it is not stainless.

Japanese chisels have hollows in the back side, the wider ones having as many as four hollows. These are intended to help in the flattening of the back of the chisels.

Wood Turning Chisels

 A lathe tool is a woodworking chisel designed to cut wood as it is spun on a lathe. These tools have longer handles for more leverage, needed to counteract the tendency of the tool to react to the downward force of the spinning wood being cut or carved. In addition, the angle and method of sharpening is different, a secondary bevel would not be ground on the tool.

Woodworking chisels range from quite small hand tools for tiny details, to large chisels used to remove big sections of wood, in 'roughing out' the shape of a pattern or design. Typically, in woodcarving, one starts with a larger tool, and gradually progresses to smaller tools to finish the detail. One of the largest types of chisel is the slick, used in timber frame construction and wooden shipbuilding.

What is a Gouge?

 A gouge, one type of chisel, is used, particularly in woodworking, woodturning and sculpture, to carve small pieces from the material. Gouges are most often used in creating concave surfaces. A gouge typically has a 'U'-shaped cross-section.

• If the angle of the plane of the blade is on the outer surface of the curve the gouge is called an 'incannel' gouge, otherwise it is known as an 'outcannel' gouge.
• Gouges with angled rather than curved blades are often called 'V-gouges' or 'vee-parting tools'.

Types of gouges

 • Straight Gouge

 • Fishtail Gouge

 • Spoon Gouge

 • V-parting Tool - used for parting, and in certain classes of flat work for emphasizing lines.

 • Veining Gouge - a specialized deep gouge with a U shaped cutting edge

 • Framing Gouge – a large (2” or wider) gouge used to scrub wood for fitment in timber framing construction.


 Gouge Parts:

 • Sweep – The curvature of the cutting edge of a carving gouge. A lower number (like #3) indicates a shallow, flat sweep while a high number (like #9) is used for a deeply curved gouge.

 • Bent – the curvature of the gouge length –

  • Long Bent – A gouge, chisel or V tool where the blade is curved along its entire length. Handy for deep work.
  • Short Bent or Spoon – A gouge, chisel or V tool where the blade is straight with a curve at the end, like a spoon. Use for work in deep or inaccessible areas.
  • Back Bent – A spoon gouge with a reverse bent end. Used for undercuts and reeding work.

 • Cannel – the curved inner surface of a gouge

Besides wood carving, gouges have a place in woodworking and timber framing. Gouges can be used to quickly wear down the surface of wood that is hard to reach with other tools – much like a scrub plane. Large gouges were used by timber framers in this manner in conjunction with the slick chisel to fit mortise-and-tenon joints.


 What is a Draw Knife?

 A drawknife is a traditional woodworking hand tool used to shape wood by removing shavings. It consists of a blade with a handle at each end. The blade is much longer (along the cutting edge) than it is deep (from cutting edge to back edge). It is pulled or "drawn" hence the name, toward the user. The draw knife provides a quick and simple way of removing large amounts of stock from timber billets. Much loved by the green woodworker, these tools have been with us since the very dawn of woodworking. There are two or three styles with variations, the most common are:

• Straight-bladed with handles set at ninety degrees to the line of the blade, also known as the English pattern

• Curved bladed style, with handles in line with the cutting edge, also known as the continental pattern.

• Folding-handles that allow the user to adjust the angle to gain maximum leverage
• Scorp - Also commonly called an inshave, is a deeply curved drawknife that has the perfect regular sweep and handle angles for rapid, aggressive shaving to finish the shaping job begun with the adze. Its deep sweep takes heavy cuts without excessive effort and without tearing at the edges of the cut.

Generally draw knives have a 20 degree bevel with a 5 degree or so back-bevel. The trick to draw knives is mastering reading the grain of the wood.

Who uses Chisels, Gouges and Draw Knives?

• Everybody that works with wood will at some point need at least a single chisel and the techniques to use it.
• Traditional furniture makers
• Timber Framers
• Wet Wood workers.
• Carvers

• Retail Stores
• eBay
• Yard and Estate Sales
• Craig’s List
• What to look for
  • Look for all the parts (iron, handle, *ferrule, *strike plate)
  • Look for cracks or chips, especially around the ferrule
  • Look at the length for stress and condition of the edge for bluing
  • How flat is the back? Convex back = bad (takes too long to knap)
  • Look for excessive pitting due to rust
  • Cheap pot-metal or sheet metal materials and soft plastic in general = bad
  • Metal striking plate is more of a carpenter’s chisel
  • Anything marked "Stanley", "Witherby", "Winchester", “James Swan”, "Chas Buck" or "L&IJ White" is generally going to a collector for too high a price unless they are part of large, handle-less lots.
  • Good brands include older (not newer) Greenlee and Buck Bros, New Haven Edge Tool, Ohio Tool, Crossman, DR Barton, Underhill, Union Hardware, Jennings, Sargent, GI Mix, Shapleigh Hardware, Eric Anton Berg, Dickerson, Gillespie, Wye, Dixon, PS&W or PEXTO, Robt Duke, Fulton, Merrill, Butcher, Stiletto, Hibbard OVB, Simmons Keen Kutter, Lakeside and several other old makers and hardware store brands are every bit as good as the collector prizes and are much less expensive. Most unmarked chisels of that era were usually made by one of the above makers for a hardware distributor and are also generally excellent.
To avoid:
  • Stanley Defiance
  • Eclipse
  • Newer Greenlee, Buck or Stanley socket chisels made in the 1960's and later
  • Any chisel with a vanadium finish like used on today's mechanic's tools


 Flattening, Grinding and Filing - ,

 • Flattening the back - the first step in sharpening a chisel. Once the back side is perfectly flat, and polished to the required degree, the front and side edges need to be addressed.

 • Hollow Grind of the blade or chisel edge

 • Stones or Scary Sharp method

 • Micro bevel

 • Stropping

Removing Knicks
• Flat Grinding perpendicular to the back past the knick.

Rust Removal
• Evaporust or Electrolysis
• Phosphoric Acid (Parkerizing)

Rust Prevention
• Waxing
• Bluing

A sharp chisel gives you great control and allows you to remove paper-thin slices of wood, but it can be dangerous if you’re not careful.

• Never chisel toward your body or place your hand in the path of a chisel
• Clamp small projects.
• Cover the chisel blade when it’s not in use.
• Store chisels in a safe place, away from children.
• Wear safety glasses when striking a chisel with a hammer.
• Wear close-toed shoes (nothing like spearing a toe)


 Short demonstration of chisel, gouge and shave use (paring, mortising, gouging)

Web Resources  (email list)

• Bob Smalser
• Scott Grandstaff

(my notes were liberally taken from materials written by the above and from the web resources  listed).
-- John