What You’ll Need
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Angle grinder
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Diamond-tipped blade
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Clamps or non-slip mat
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Straightedge (metal ruler or level)
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Chalk or pencil
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Water
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Safety gear
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Safety glasses or face shield
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Dust mask or respirator
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Hearing protection
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Gloves
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Safety First (Don’t Skip This)
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Work outside or in a very well-ventilated area
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Keep hands well clear of the blade path
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Let the grinder reach full speed before cutting
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Never force the cut—slate can snap unexpectedly
Step 1: Mark Your Cut
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Use chalk or a pencil to mark your cut line
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For straight cuts, line up a straightedge and clamp it down as a guide
💡 Tip: Mark both the top and underside if precision matters.
Step 2: Secure the Slate
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Place the slate on a stable surface (workbench or plywood on sawhorses)
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Clamp it firmly so it cannot vibrate or move
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Leave the cut line slightly overhanging the edge of the bench
Step 3: Score the Slate (Important)
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Hold the grinder with both hands
- Wet the slate.
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Make a light pass along the cut line
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Don’t try to cut through on the first go
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This scores the surface and reduces chipping
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Step 4: Make the Cut
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Slowly deepen the cut with multiple shallow passes
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Let the blade do the work—no pressure
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Keep the grinder straight and steady
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For thicker slate, cut halfway through, then flip it and finish from the other side
💡 Tip: If the slate starts to heat up, pause briefly.
Step 5: Finishing the Edge
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Use the grinder at a slight angle to smooth rough edges
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Light passes only
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For a natural look, lightly “soften” the edge rather than squaring it perfectly
Reducing Dust
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Lightly mist the cut line with water
OR -
Have someone hold a shop vacuum hose near (not touching) the cut