One of the most common ways of cleaning and prepping a material for coating or plating is to sandblast it. This method, also known as abrasive grit blasting, involves using an industrial or commercial sandblaster to treat the surface of a substrate metal or plastic. The sand of abrasive grit blaster sends a controlled stream of abrasive media through a nozzle.
Media: Types and Best Usage
Choosing the right media is something best left to the professionals. They know exactly how much pressure the substrate surface is capable of taking. As a result, they choose their media wisely from a list that no longer includes the namesake for the process – sand.
The type of treatment and finish a substrate metal or plastic requires lies with the medium. If the wrong one is selected and employed, it can destroy or negatively affect the surface of the base or substrate. Of the many potential candidates for use in a commercial sandblaster the following are among the most common and even popular.
- Acrylic: This is used if the substrate surface is extremely sensitive. It can strip without causing damage. It is durable and used for delicate parts and aircraft components.
- Aluminum Oxide: This gentle medium is long-lasting but presents some challenges for disposal
- Corn Cob Grit: A biodegradable abrasive, this medium does not etch the surface off the substrate
- Crushed Glass Grit: Comprised of recycled bottle glass, this particular medium acts similar to glass bead abrasive particles. They can be recycled for further use and applied to deburr, descale and texturize. The result is a soft, attractive finish
- Glass beads: See crushed glass grit
- Melamine: A plastic abrasive, this is the hardest and is perfect when both a high stripping rate and no damage to the substrate are required
- Pumice: Not for use on metals, this gentlest of abrasives is best suited for removing paint from wood
- Silicon Carbide: When the going is tough, finishers turn to silicon carbide. This hard medium has a fast cutting speed it combines with shorter blast times lower overall cost per hour and high recyclability. Altogether a favorite method for many finishers
- Steel Grit: This medium leaves behind an etched surface. This makes it easier for any other material to adhere to the substrate surface
- Steel Shot: See Steel Grit
- Urea: Of plastic abrasive medium, this is the most popular. It is commonly used to restore vehicles. It easily strips quickly and efficiently without causing damage to the substrate.
- Walnut Shell Grit: Used for thermoset plastics, this totally biodegradable and not-so-abrasive abrasive, does not damage the original polish.
Commercial Sandblaster
There are several reasons why companies perform sandblasting. The process may be required to remove an old finish. It also can be employed to take off rust or prepare the surface for another process. The exact medium the commercial sandblaster will use to accomplish such tasks will depend on the type of surface treatment the finishing company and the customer desire and specifications require.