Uneven or Wandering Grind Lines
Symptom
Plunge lines don't match from one side of the blade to the other, the bevel wanders wider or narrower along the blade's length, or grind lines aren't straight and parallel no matter how carefully you try to hold the work.
Likely Causes
- Inconsistent hand pressure or angle as you move the blade across the platen
- A worn, grooved, or unevenly-glazed platen surface that no longer gives a true flat reference
- Body position shifting during longer grinding passes instead of staying consistent
- Not using a consistent reference point (like a marked angle or a work rest) to guide the pass
- Switching grits or belts mid-blade without re-establishing the existing line first
Quick Checks
- Run a straightedge along the platen surface to check for grooving or unevenness
- Compare the plunge line angle on both sides of the blade against each other directly
- Watch your stance and grip partway through a pass, has it drifted from where you started
Fixes
- Slow down and take lighter, more frequent passes rather than one long aggressive pass
- Use a marked reference line or angle guide until consistent muscle memory is built
- Resurface or replace a grooved platen rather than grinding against an uneven reference
- Reset and re-establish the existing grind line before switching to a new belt grit
- Consider a work table or angle-holding attachment while building consistency
Prevention
- Practice consistent body positioning and stay square to the platen throughout each pass
- Inspect and true up the platen surface periodically rather than waiting until it’s visibly grooved
- Mark reference lines on practice blades until the correct angle becomes automatic
When to Stop and Get Help
If the blade is already significantly asymmetric or over-thinned on one side while chasing an even line, stop and reassess rather than continuing to grind, it's easy to grind away the material needed to fix the problem.