Sandblasting is a process in which sand, glass beads, or some other medium is shot at high speed through a machine across the surface of a rigid material until it is sanded smooth. Sandblasting is often done to remove a previous finish on an item, remove rust, or prepare a surface to receive a new paint coat. The medium used to blast the body depends on how complicated the removal is and how much impact the material can withstand.
Below are more instructions for how to choose the right sandblasting media.
- Start with a gentle medium if you are uncertain. If you are unsure how the material will withstand sandblasting, it is best to choose the gentlest medium and work your way up. Walnut shells are one of the less abrasive sandblasting media you can use and are completely biodegradable, so there are no environmental impact concerns. Corn cob is also biodegradable and will not etch the material being blasted. Pumice is the softest of all the blasting media. It is often used to remove paint from softwood.
- Consider glass beads as a medium. Glass beads give a soft, bright finish that is more attractive than angular media. Glass beads can be recycled up to 30 times. Crushed glass grit made from 100 percent recycled bottle glass is also available.
- Choose plastic beads for automotive sandblasting. Plastic beads are made out of acrylic, polyester, melamine, and urea. They deliver a high stripping rate without damaging or warping the underlying material.
- Take care with clean-up if you use aluminum oxide, another gentler medium on the sandblasting palette. It is composed of small grains of aluminum oxide and is very long-lasting. The disadvantage of this medium is that you must carefully dispose of the material after it is used.
- Use silicon carbide for the most challenging jobs. Silicon carbide is the most demanding medium available for sandblasting. It allows for shorter blast times and lower costs overall than other media. It can be recycled more times than aluminum oxide or sand.
- Pick steel grit or steel shot for unique finishes. Though softer than aluminum oxide medium, steel grit leaves an etched surface that makes it easier for paints to adhere. Steel shot is used for peening operations to leave a smooth, polished finish. The image can be used up to 3,000 times and produces minimal dust.
- Try dry ice sandblasting. One of the newest sandblasting methods uses compact dry ice pellets shot in a jet of compressed air. Dry ice is used to clean machinery, electrical installations, electromechanical equipment, and other surfaces where the residue from standard sandblasting techniques would be detrimental.