White corundum for glass etching

Why White Corundum is Ideal for Glass Etching

1. Superior Hardness (9.0 on Mohs scale):​ It is significantly harder than glass (~5.5 Mohs), allowing for efficient and fast material removal without excessive wear on the abrasive itself.
2. Sharp & Angular Grains:​ The crystalline structure fractures to form sharp edges, providing excellent cutting action for a clean, frosted etch.
3. High Purity (Al₂O₃ >99%):​ The low iron oxide content prevents yellowing or discoloration of the etched surface, resulting in a pure, bright white frosted finish crucial for aesthetic work.
4. Consistency & Durability:​ It offers a consistent etching rate and can be partially recycled in closed-loop sandblasting systems, making it cost-effective for production.
5. Versatility:​ By varying the grain size (grit), you can achieve different finishes, from a coarse, pebbly texture to a very fine, satin-like frost.

How to Use White Corundum for Glass Etching (Sandblasting Method)

Required Equipment & Materials

• Sandblaster Cabinet​ (with dust collection)
• Air Compressor​ (with moisture filter)
• White Corundum Abrasive​ (select appropriate grit)
• Safety Gear:​ Respirator​ (NIOSH-approved for silica/abrasive dust), safety goggles, gloves.
• Glass Substrate
• Abrasion-Resistant Stencil/Resist:​ High-tack vinyl, rubber, or specialized sandblast tape.

Step-by-Step Process

1. Design & Stencil Application
   • Create or obtain your design digitally.
   • Cut the design into the stencil material (vinyl) using a plotter/cutter.
   • Weed​ (remove) the parts of the stencil that correspond to the areas you want etched. Apply the stencil firmly to the clean, dry glass, ensuring no bubbles or lifted edges.
2. Abrasive & Machine Setup
   • Fill the sandblaster’s hopper with your chosen grit of white corundum.
   • Ensure the air supply is dry to prevent clogging.
   • Key Parameter Settings:
     • Grit Size:​ See selection guide below.
     • Air Pressure:​ Typically 60-100 PSI (0.4-0.7 MPa). Start low and test. Higher pressure etches faster but can be harder to control and may wear stencils faster.
     • Nozzle Distance:​ 5-15 cm from the glass surface.
     • Nozzle Angle:​ 90 degrees for a uniform matte finish; angling can create shading effects.
3. Sandblasting Execution
   • Place the glass inside the cabinet.
   • Put on all safety gear.
   • Using steady, even passes, blast the exposed glass areas. Overlap strokes to ensure uniformity. The etching depth/frost density is controlled by blast time and pressure.
4. Cleaning & Finishing
   • Once satisfied, carefully remove the glass from the cabinet.
   • Peel off the stencil.
   • Rinse the glass thoroughly with water to remove all abrasive dust.

Grit Size Selection Guide