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Activity 002: Guided Tool Sharpening Lab

Activity ID: U7M2-ACT-002 Duration: 45 minutes Objective: Sharpen a spindle gouge and a scraper using the Wolverine jig system on a slow-speed bench grinder.

Overview

Students perform supervised tool sharpening, learning to set up the Wolverine jig, grind a consistent bevel on a spindle gouge, and raise a burr on a round-nose scraper. This is a foundational skill that must be mastered before independent turning.

Materials & Equipment Needed

  • Slow-speed bench grinder (1725 RPM) with 80-grit white aluminum oxide wheels (or CBN wheels)
  • Wolverine jig system (V-arm and platform)
  • Spindle gouge (practice tool—pre-dulled)
  • Round-nose scraper (practice tool)
  • Angle gauge or protractor
  • Burnishing rod (hardened steel)
  • Magnifying loupe
  • Permanent marker (for bevel marking technique)
  • Safety glasses (mandatory)
  • Face shield

Instructions & Procedure

Phase 1: Grinder Setup and Safety (5 minutes)

  1. Inspect grinding wheels for cracks (ring test—tap lightly, listen for a clear ring vs. dull thud).
  2. Verify wheel guards and spark deflectors are in place.
  3. Check that tool rest/jig is securely mounted.
  4. Start grinder and let it reach full speed. Stand to the side during startup.
  5. Dress the wheel if glazed (instructor demonstration).

Phase 2: Spindle Gouge Sharpening (20 minutes)

  1. Insert the spindle gouge into the Wolverine V-arm. Adjust arm length to achieve a 35° bevel angle.
  2. Color the existing bevel with permanent marker (this shows where grinding contact occurs).
  3. With the grinder off, present the tool to the wheel. Verify full bevel contact by checking the marker pattern.
  4. Start the grinder. With light pressure, contact the bevel to the wheel at the center of the flute.
  5. Slowly rotate the handle to sweep the edge across the wheel, maintaining consistent pressure. Rotate approximately 45° each direction from center.
  6. Make 3-4 passes. Remove and inspect: the marker should be evenly removed across the entire bevel.
  7. Check the edge with the loupe—look for a consistent, keen edge with no reflected light.
  8. Remove any burr from the flute interior with a diamond slip stone.
  9. Test sharpness on end grain scrap.

Phase 3: Scraper Sharpening and Burr Raising (15 minutes)

  1. Set the Wolverine platform to achieve a 75° angle.
  2. Lay the scraper flat on the platform, top face up.
  3. Grind the edge with 2-3 light passes until a fresh, clean edge is visible.
  4. Remove from the grinder. Hold the scraper in a vise or on the bench edge.
  5. Using the burnishing rod, draw firmly across the top edge at 5-10° above horizontal.
  6. Make 3-4 burnishing passes with firm, even pressure.
  7. Check with the loupe: a tiny rolled burr should be visible along the entire edge.
  8. Test on scrap: the scraper should produce thin, curled shavings, not dust.

Phase 4: Clean-Up (5 minutes)

  1. Clean grinding area of metal filings.
  2. Apply paste wax to sharpened tool blades.
  3. Return all tools and jigs to proper storage.

Discussion Points

  • What happens if you press too hard against the grinding wheel?
  • How can you tell if a gouge has a consistent bevel vs. uneven grinding?
  • Why does the marker technique help beginners?
  • How often would you sharpen during a typical turning session?

Expected Outcomes

  • Students produce a clean, consistent bevel on the spindle gouge
  • Students raise an effective cutting burr on the scraper
  • Students demonstrate proper grinder safety procedures
  • Students can assess their sharpening results using the loupe and cutting tests

Assessment Rubric

Criteria Excellent (4) Proficient (3) Developing (2) Beginning (1)
Gouge Bevel Even contact across entire bevel, sharp edge Minor uneven areas, functional edge Uneven bevel, partially sharp Cannot achieve consistent contact
Scraper Burr Consistent burr, produces shavings Burr present but uneven Partial burr, inconsistent cutting Cannot raise a burr
Grinder Safety All safety checks performed independently Minor omission, self-corrected Required prompting on 2+ checks Unsafe behavior observed
Technique Smooth, controlled movements, light pressure Occasional heavy pressure Inconsistent technique Requires continuous guidance

Safety Considerations

  • Safety glasses are mandatory—grinding produces metal sparks and particles
  • Never grind on the side of the wheel unless it is specifically designed for side grinding
  • Stand to the side when starting the grinder—wheel failure is most likely at startup
  • Keep fingers behind the tool rest at all times
  • If the tool catches between the wheel and rest, release immediately—do not fight it
  • Long hair must be secured; no loose clothing or jewelry near the grinder

Last Updated: 2026-03-19