White Fused Alumina 150# for Aluminum Tube Sandblasting
1. Application Suitability
Aluminum is soft in texture, prone to denting, sand embedding and oxidation discoloration. White fused alumina 150# (F150) is a widely used grade for aluminum tube sandblasting.
- Made of high-purity alumina with no iron impurities; no rust spots or contamination will form on aluminum surfaces after sandblasting.
- Moderate grit size balances cleaning efficiency and uniform matte finish, avoiding excessive material erosion on aluminum substrates.
2. Key Specifications of White Fused Alumina 150# (Grade Preferred for Aluminum Tubes)
- Al₂O₃ ≥ 99.0% (High-purity Grade 1 white fused alumina)
- Fe₂O₃ ≤ 0.05% to prevent rust specks on aluminum workpieces
- Ultra-low magnetic content to minimize embedded sand defects
- Grain size: F150, corresponding particle size approx. 53～67 μm
3. Applicable Working Conditions
- Removal of oxide scales, oil stains, drawing lines and minor scratches on aluminum tubes
- Surface roughening pretreatment prior to anodizing, painting or coating to enhance coating adhesion
- Uniform matte finishing and surface matting for aesthetic purposes
4. Recommended Sandblasting Process Parameters (Prevent aluminum deformation, gouging and sand embedding)
- Operating air pressure: 0.20～0.35 MPa
For thin-walled aluminum tubes (wall thickness ＜ 1 mm): adopt 0.20–0.25 MPa; high pressure easily causes indentation and deformation.
- Blasting distance: 120～200 mm
- Blasting angle: 30°～45°; avoid direct perpendicular blasting at 90°.
- Gun travel speed: move the gun at constant speed; do not hold the nozzle aimed at a single spot for prolonged blasting.
- Recycling mode: closed-circuit recycling blasting; white fused alumina can be reused multiple times.
5. Reference Surface Roughness
Aluminum tube surface Ra value after blasting with F150 white fused alumina is generally 15～35 μm.
Roughness can be adjusted by modifying air pressure and blasting distance to meet pretreatment requirements for painting or anodizing.
6. Advantages & Disadvantages
Advantages
- Iron-free pure white abrasive, no subsequent rust discoloration on aluminum parts
- Angular grains deliver moderate cutting power for consistent scratch removal and roughening effect
- Reusable to control overall abrasive consumption cost
- Uniform matte surface with excellent appearance consistency
Potential Risks
- Excessive air pressure may cause abrasive embedding into aluminum matrix, resulting in pinhole defects during subsequent anodizing treatment.
- Compared with glass beads, it produces relatively coarser surface texture; switch to 220# / 320# white fused alumina for finer matte and lower roughness.
- Relatively high dust generation, requiring matched dust extraction equipment.
7. Alternative Grit Selection Reference
- Faster scratch removal, coarser surface: 120# white fused alumina
- Finer matte finish, lower roughness: 200# / 220# white fused alumina