What is the primary difference between a spindle roughing gouge and a bowl gouge?
Explanation: A spindle roughing gouge has a wide, shallow U-shaped flute and thin cross-section that cannot withstand the lateral forces of faceplate turning. A bowl gouge has a deep, parabolic flute with a heavier cross-section designed for the varying grain encountered in bowl work. Using a roughing gouge on a faceplate-mounted piece risks catastrophic tool failure.
What steel type is most commonly used in modern wood turning tools for its ability to hold an edge at high temperatures?
Explanation: HSS (M2 or M42 grade) maintains its hardness at temperatures up to 1100°F, making it ideal for wood turning where friction-generated heat is constant. Carbon steel loses its temper at much lower temperatures. Powdered metal (PM) HSS variants like CPM-10V offer even greater edge retention.
What is the typical bevel angle for a spindle gouge used in general spindle turning?
Explanation: Spindle gouges are typically ground to 30-40 degrees. A lower angle (30°) gives a more aggressive cut for soft woods, while a steeper angle (40°) provides more support and durability for harder woods. Bowl gouges are often ground to 45-65 degrees with swept-back wings.
What grinding wheel grit is recommended for sharpening HSS turning tools?
Explanation: 60-80 grit wheels provide an efficient balance between metal removal rate and edge quality for HSS tools. Aluminum oxide (white or pink) wheels run cooler than gray silicon carbide. CBN (Cubic Boron Nitride) wheels are premium options that never need dressing and cut cool.
Why should you NEVER use a spindle roughing gouge for faceplate or bowl turning?
Explanation: Spindle roughing gouges have a thin cross-section and are attached to the handle via a tang (a pointed rod driven into the handle). The lateral forces encountered during faceplate turning can snap the blade at the tang, sending a sharp piece of steel flying. This is one of the most critical safety rules in wood turning.
What is the function of a skew chisel in wood turning?
Explanation: The skew chisel is the premier finishing tool for spindle work. Its angled edge can produce glass-smooth planing cuts, crisp V-cuts, and decorative beads. It requires skill to use due to its tendency to catch if improperly presented.
What is a "catch" in wood turning?
Explanation: A catch occurs when the cutting edge is presented in a way that allows the rotating wood to grab the tool and pull it violently into the workpiece. This can damage the workpiece, injure the operator, or throw the workpiece. Catches are most common with skew chisels and scrapers presented above center.
What angle should a parting tool be presented relative to the workpiece axis?
Explanation: A parting tool is presented perpendicular to the workpiece axis to cut a narrow groove straight into the wood. It is used to establish diameters, create tenons, and separate finished pieces from waste stock.
When sharpening on a bench grinder, what is the purpose of a jig system like the Wolverine or Tormek?
Explanation: Sharpening jigs hold the tool at a fixed angle relative to the grinding wheel, ensuring consistent bevel geometry every time. Freehand grinding can produce uneven bevels that affect tool performance. Systems like the Wolverine (for bench grinders) and Tormek (wet grinder) are industry standards for wood turning tool sharpening.
What visual indicator tells you a turning tool needs sharpening?
Explanation: A sharp tool slices wood fibers cleanly, producing ribbons or shavings. A dull tool tears fibers, producing dust and a rough surface. The operator also needs to apply more force, which increases catch risk. Frequent sharpening (every 15-20 minutes of turning) maintains optimal cutting performance.
What type of scraper is best suited for finishing the interior of a bowl?
Explanation: Round-nose scrapers conform to concave interior surfaces. When properly sharpened with a slight burr raised on the top edge, they produce a smooth finish on bowl interiors where gouges are difficult to control. The curved profile matches the bowl's interior curve.