There are so many methods out there for applying an industrial-grade metal coating to products and objects.
For the most part, it depends heavily on the outcome you want. If you’re looking for aesthetically pleasing precious metal coating for jewelry, or rock hard coating for auto parts, you’ll probably opt for a different metal finishing application method.
One great method for coating products for preservation, corrosion prevention, and protection is abrasive blasting. This method is also sometimes used for engraving.
What is Abrasive Blasting?
Abrasive blasting, which is also known as sandblasting, is a method of industrial metal finishing that uses blast equipment to push a large range of media and grits. Typical blast equipment used includes air pressure, centrifugal wheel blasting, and wet blasting. Typical media includes glass beads, aluminum oxide, steel shot, baking soda, walnut shells, and plastic.
Abrasive blasting has been in use for many years and can be very effective. A variety of blasting methods are used by different industries around the world to remove paint and debris, prepare surfaces for metal coatings, strengthen metals, to clean rust and grease, and to engrave stones. Abrasive blasting is used as an inexpensive and quick method for all of these purposes. You can also use blasting in place of potentially harmful chemical strippers and solvents.
With the now known health dangers of using silicon in sandblasting, alternative types of media offer safe blasting options. It is also more effective in protecting substrates damaged with sandblasting, which is cost-effective.
Abrasive blasting commonly uses pressurized air or water to propel abrasive media against a surface to remove coating or corrosion, making it an ideal form of cleaning and polishing.
Abrasive blasting is used for a number of other things:
- Making a rough surface smooth.
- Making a smooth surface rough.
- Shaping a surface.
- Removing surface contaminants or materials such as paint, rust, or residue.
- Cleaning or prepare a surface.
- Finishing a surface.
Equipment for Abrasive Blasting
Portable abrasive blasting equipment from industry leaders such as Wheelabrator is used for the onsite blasting of cars, ships, homes, buildings, stone, brick, metal, and wood.
Blast rooms are where blasting equipment is typically used with specialized dust collection systems to protect against fire hazards and air contamination. Plus, airtight blast cabinets offer solutions for blasting significantly tinier parts. Blast cabinets and rooms make for easy clean up of media, which in many cases is reclaimable and reusable multiple times. Again, very cost-effective.
What Media is Ideal for Abrasive Blasting? Soft vs Hard Abrasives
The selection of the correct abrasive blasting media type is critical and depends on the product you want to coat.
Abrasive media includes hard abrasives and soft abrasives. Hard abrasives include materials such as aluminum oxide, garnet, silicon carbide, steel shot, and glass beads. Hard abrasives are usually used to remove rust from hard metals, introducing a smooth surface to metal surfaces. Soft abrasives for abrasive blasting typically include walnut shells, plastic blast media, baking soda, and wheat starch.
Soft abrasives are used to remove paint, debris, and coatings from hard and soft metals such as steel and aluminum. It is also used to clean soft substrates such as composites, fiberglass, rubber, and plastics. Soft abrasives can safely remove paint and coatings from very delicate surfaces without etching or marring when used with the proper blast parameters. Abrasive blasting with soft abrasives is usually used for paint removal from cars, trucks, furniture, and other hearty products or machinery.
Some of the type of abrasive media that may be used in different abrasive blasting applications include:
- Crushed glass
- Ceramic grit
- Walnut shells
- Corn Cobs
- Steel shot for “shot blasting”
- Steel grit
- Glass beads for “bead blasting”
- Aluminum oxide
- Apricot powder
- Peach powder
- Plum stone powder
- Dry Ice
- Silicon carbide or “carborundum”
- Sodium bicarbonate for “soda blasting”
- Plastic grit
- Coal slag
- Copper slag
- Cut wire
What type of blast media one should use is dependent on the end product one would want to achieve. Blasting media comes in a significant variety of density, hardness, and particle size. It is critical to match the right type of abrasive media to the job and the method of abrasive blasting.
How Does Abrasive Blasting Work?
There are typically three parts to an abrasive blasting system, all of which depend on the type of product being blasted:
- Using an abrasive container or “blasting pot”
- Using a propelling device or mechanism
- Using a blasting nozzle
In many cases, compressed air or a wheel propels the media at the surface to be blasting. In a blast cabinet or blast room, the abrasive blasting media may be reused and recycled until used up completely. Compared to other coating or cleaning methods, abrasive blasting can be very eco-friendly. In outdoor blasting, the used media can even be recycled.
Parameters for Abrasive Blasting
There are a number of important abrasive blasting parameters:
- Pressure or “PSI”
- Nozzle distance
- Media type
- Media size
Each blasting operation needs careful calibration of these various factors to ensure the most efficiency without damaging the surface or product parts. Usually, harder surfaces with thicker coatings will need aggressive media at higher PSI. More delicate and lightweight surfaces will require softer media at lower PSI. Nozzle distances can also vary from one to four feet depending on the surface, coating, and media used in the blasting process.
Is Abrasive Blasting the Best Choice for My Products?
Abrasive blasting could be a great choice for your specific products, but it significantly depends on the type of product you’re trying to coat. Send us a quote request over al ABITL, and we can help you decide if abrasive blasting is the right choice for you!
ABITL is an industrial metal finishing company that utilizes Wheelabrator sandblasting equipment in the process of coating a number of products of any size at the most affordable prices. In addition to sandblasting, ABITL also offers services involving batch coating, automated coating, and powder coating.
Do you prefer abrasive blasting over other forms of industrial metal finishing? Tell us about your experience with industrial metal finishing and abrasive blasting in the comments below.
Photo source: Pixabay