Sandblasting versus media blasting
“Sandblasting” is still the common name, but modern blasting rarely uses sand. Traditional sand is silica, and breathing silica dust can cause serious lung disease (silicosis), so it is restricted or avoided in many places. “Media blasting” or “abrasive blasting” is the broader term: the same equipment propels a chosen abrasive at a surface to clean, strip, texture or finish it. The medium changes the result far more than the machine does.
How to choose media
Consider these factors:
- Base material. Soft metals, plastics and wood need gentler media than steel.
- Goal. Cleaning, paint or rust removal, deburring, peening, or a uniform matte or satin finish.
- Hardness and shape. Hard, angular media cuts fast and leaves a rougher profile. Round media peens and smooths.
- Particle size (grit). Coarser grit works faster but leaves a rougher surface.
- Reusability and cost. Some media break down quickly; harder media can be recycled many times in a cabinet.
- Contamination. Iron-containing media can leave residue on aluminum or stainless steel.
Always test on a scrap piece before blasting the real part.
Soft media
Soft media suits delicate surfaces and coating removal.
- Sodium bicarbonate (baking soda). Gentle and water-soluble, used for cleaning engines and delicate parts and for stripping paint from softer substrates. Usually single-use.
- Walnut shell. A natural, mild abrasive often used on wood, fiberglass and delicate parts where you do not want to pit the surface.
- Corn cob. Even softer, used for light cleaning and polishing.
- Plastic media. Engineered plastic pellets used in coating removal from thin or sensitive parts where metal must not be damaged.
Medium media
- Glass bead. Round beads that leave a clean, bright, satin finish and can peen the surface lightly. Popular for stainless steel, aluminum and finishing small parts.
- Crushed or ground glass. A silica-free, economical alternative to sand for general cleaning and paint removal on metal. It is angular and cuts more aggressively than beads.
Hard media
- Aluminum oxide. A hard, sharp, long-lasting abrasive, widely used in hobby cabinets for etching, rust removal and surface prep before painting or coating. Available in many grit sizes.
- Garnet. A natural mineral abrasive that cuts well and is commonly used for general-purpose and wet blasting.
- Silicon carbide. Very hard and sharp, used for tough jobs and for etching hard materials like glass; it breaks down faster in some uses.
- Steel shot and steel grit. Very hard and heavy, typically used in industrial settings for heavy rust, scale and peening. Not suited to most small hobby cabinets.
Quick chooser by task
| Task | Typical media to consider |
|---|---|
| Gentle cleaning, delicate parts | Baking soda, corn cob, walnut shell |
| Removing paint from soft metal or fiberglass | Walnut shell, plastic media |
| Bright satin finish on metal | Glass bead |
| General rust and paint removal | Crushed glass, aluminum oxide |
| Etching and heavy surface prep | Aluminum oxide, garnet, silicon carbide |
| Heavy industrial scale removal | Steel grit or shot |
Parts made by 3D printing or molding can also benefit from blasting. Fine glass bead is often used to even out the surface of printed parts, but plastics are easily damaged, so start with low pressure and fine, soft media. For molded parts with flash, see injection molding flash removal.
Can you blast brass?
Yes, brass can be media blasted. Because it is a soft metal, a gentler medium such as glass bead or fine walnut shell is a common choice, at moderate pressure, to avoid pitting or removing too much material. Harder, coarser media can leave a rough or uneven surface. Test on a scrap piece first.
Alternatives to sandblasting
If blasting is not practical, alternatives include:
- Chemical strippers or rust removers, following product safety instructions.
- Wire brushing and sanding for small areas.
- Wet blasting, which uses a slurry and produces less dust.
- Soda or dry-ice blasting, which are gentler cleaning options.
- Tumbling or vibratory finishing for small parts in batches.
Safety basics
Dust, noise and flying particles are real hazards. Use a proper blasting cabinet where possible, eye and hearing protection, and a respirator rated for the media and the coating being removed. Be especially careful with old paint, which may contain lead. Avoid free silica sand. Follow the media manufacturer’s safety data sheet and local regulations.