Sandblasting cannot be done without the use of sandblasting media. The media used for each job depends on its application. Having a knowledge of different types of sandblasting media with their applications will help you in selecting the media that serve your needs.
I have researched and listed different types of sandblasting media, their properties, and how to select the best media suitable for your job.
Let’s take a look at this definitive guide…
What is sandblasting media?
Sandblasting media are the abrasive materials forcibly propelled against a surface under high pressure to achieve the following; to prepare a surface for coating, to smooth the surface of a material, to remove old paints, to remove rust, to finish, remove contaminants, etc.
Types of Sandblasting media
The process of sandblasting is carried out using different types of sandblasting media, which depends on its applications. Some of these sandblasting media are;
- Aluminum oxide
- Glass beads
- Crushed glass
- Silicon Carbide
- Corn cob
- Walnut shell
- Steel grit
- Steel shot
- Baking soda
- Dry ice
Properties of sandblasting media to consider
The following properties are factors to be considered when determining the result of sandblasting process.
When you are choosing sandblasting media for your job, you need to understand that the shape of your media plays a huge role in impacting the depth to which it cuts the surface. Listed below are the major categories of media shape;
These are smooth materials, which can also be spherical that are capable of creating a more even, dimpled profile. The same is also applicable to sub-rounded materials. Examples of rounded materials are glass beads.
These materials can cut through rust, clean faster, cause a higher, and can shape anchor patterns well because they are jagged materials. It is capable of forming deeper, sharper, and anchor patterns.
Examples of angular or sub-angular materials are aluminum oxide and crushed glass.
Examples of sub-angular media are plastic and garnet abrasives.
In choosing the suitable media that serve your need, it’s important to understand the effect of media sizes on the material being sandblasted.
When you use larger abrasive media, they will cause deeper indentations with little impact on the material when compared with using smaller particles.
I’ll advise that you use smaller media to get the best sandblasting result. The sizes can be measured as follow –
- Grit size
- Mesh size.
Mohs scale of mineral hardness is used for measuring the hardness of abrasive media. When you have media with a lower Mohs number, it means the media is soft and for a higher Mohs number, it indicates the media is hard. Note that harder materials will have a greater effect and cause a deeper profile. Examples of soft sandblasting media are walnut shells, corn cob, baking soda, walnut shells, and wheat starch. While of hard media are aluminum oxide, garnet, steel grit, steel shot, garnet, and glass beads.
Guide to sandblasting media grit size
Sandblasting media chart
The sandblasting media needed for your sandblasting operation vary in hardness, mesh sizes, density, shape, and hardness. These differences play a huge role in determining how effective your media are.
The sandblasting media chart discussed below elaborate more on their differences.
|Sandblasting Media||Applications||Mohs Hardness||Sizes||Shape||Density|
|Walnut shell||Surface cleaning without causing damage to the material||4 -5||6-100||Sub-rounded and sub-angular||1.2-1.35|
|Steel shot||Polishing the surface of a material||8||7-120||Rounded||4.8-7.8|
|Staurolite||Applicable for higher etch surface profile and for aggressive cleaning||8||10-200||Angular and sub-angular||4.8-7.8|
|Silicon carbide||For cutting and causing deep etch on hard materials like stones and glass||9-9.5||8-325||Angular||3.2-3.22|
|Aluminum oxide||For etching surface profile||9||12-325||Angular while some are also sub-angular||3.94-3.96|
|Corn cob||It is used for cleaning soft surfaces like wood||4-4.5||12-325||Sub-angular||1.2-1.4|
|Glass Beads||Ideal for finishing steel||5-6||30-325||Rounded||2.5|
How to choose the right sandblasting media?
In choosing the right sandblasting media that best suits your job, the instructions discussed below will guide you.
If you aren’t sure of what media to select, I’ll advise that you begin with gentle or soft media that won’t cause damage to your material. You can go for a walnut shell, corn cobs, pumice, and other less abrasive materials that are biodegradable.
When you want to machinery electrical installations and other electromechanical equipment, it’s best to adopt dry ice as your sandblasting media.
When dealing with tough jobs, you need media that allow shorter blast times and less expensive, a good example of such media is silicon carbide.
If the job at hand is to finish a special surface, go for materials that are softer than aluminum oxide. A material that leaves an etched surface, makes it easier to hold paint. Examples of such materials are steel grit and steel shot.
For operators who sandblast automobiles, you need a sandblasting medium that delivers a high stripping rate without causing damage to the automobile. Media such as plastic beads best fit into this category.
The Best sandblasting media
List the best sandblasting media. Give a brief intro and for what they are most used.
Which is the best sandblasting media for rust removal?
The best sandblasting media for removing rust from the surface of a metal is silicon carbide because it is a hard abrasive material that provides an extremely aggressive cutting action used for fast etching hard materials and best for removing rust.
Which is the best sandblasting media for paint removal?
The best sandblasting media for removing paint is aluminum oxide. It is the best for this job because of its hardness and sharpness, which is ideal for general cleaning and paint removal.
Which is the best sandblasting media for glass etching?
Glass etching can be effectively carried out by the use of silicon carbide as the abrasive media. Its aggressive cutting action makes it ideal for glass etching.
Which is the best sandblasting media for aluminum?
If you have a surface that is aluminum, you need a medium that isn’t as hard as aluminum nor capable of creating surface profiles which could lead to corrosion. The best media to use in sandblasting aluminum material are glass beads, walnut shells, and sodium bicarbonate.
Sandblasting media cost
The cost of your sandblasting media depends on the following factors;
- Size of the surface you want to sandblast
- the intensity of sandblasting you use ranges between $1per square foot to $16 per square foot.
- Methods used, that is, what you used in pressuring the sandblasting media onto the surface of the material being sandblasted.
- The type of cleaning
- The amount of media spent
- Lastly, the type of surface you are sandblasting also determines the overall cost of your media.
How to recycle sandblasting media?
Sandblasting media are recycled to increase the useful life before the media is no longer useful for removing paint or rust from surfaces. Things needed to carry out the process of recycling on sandblasting media:
- A special blasting cabinet is needed to recycle media.
- Sized screens or filters
Listed below are the step-by-step methods for recycling a medium;
- Use a collection bin to collect the blasting material from the bottom of the blasting cabinet.
- Filter out the collected materials such as baking soda or crushed walnut shells with the use of a screen.
Note: A screen with larger holes is advised, to filter debris from coarse abrasive media.
- You need a catch bucket to collect the media after being poured through the screen. After screening the material, dispose of the debris into a bin. When you are done disposing of the debris, your recycled media is ready to be loaded into the media blasting reservoir to be used for your sandblasting operation again.
How to clean sandblasting media?
As an operator or user of sandblasters, you can clean your sandblasting media to make them useful for the next job.
A vacuum recovery system can be used to clean your media. It does this by allowing you to pick up sandblasting media at a fast pace. The use of a basic front-end loader can also be employed.
You can also use a mechanical or pneumatic blast recovery system to clean your blast media, it cleans media by the use of a dust collector.
How to dispose of sandblasting media?
There are some factors you need to consider before disposing of your blast media that have used up their shelf-life. Some of those factors are;
- Are the blast media hazardous?
- Are the blast media non-hazardous?
- What is your waste service doing?
For hazardous media that contain heavy metal, it can be disposed of accordingly by your waste service. While for non-hazardous media, they can be disposed of in a container and handed over to your waste service.
Can you reuse sandblasting media?
Some blast media cannot be reused because of the low hardness of the media, which get shattered into particles when forced on the material being sandblasted. However, plastic blast media, garnet, steel shot, and glass beads can be reused more than one time.
Can you mix sandblasting media?
Yes, you can mix one mesh size or type of blast media with another can give improved and improvised sandblasting operation. Blast media with smaller mesh sizes can be mixed with another to clean a metal profile. If you are a beginner, you can start with a lower blast pressure and move higher as your skills increase.
How much sandblasting media do I need?
The amount of sandblasting media you need depends on the volume of work you want to sandblast. For larger jobs, you will need a higher number of sandblasting media and vice versa.
How long does sandblasting media last?
If you are using recycled glass as your blast media, they will last a minimum of half an hour to approximately an hour. For carbide grit media, they last long but are quite expensive. However, how long a blast medium lasts depends on abrasive dose setting and Blast pressure setting.
To get the best out of your sandblasting operation, you need to understand the applications of each blast media which have been discussed in this article.
- What is sandblasting media?
- Types of Sandblasting media
- Properties of sandblasting media to consider
- Guide to sandblasting media grit size
- Sandblasting media chart
- How to choose the right sandblasting media?
- The Best sandblasting media
- Which is the best sandblasting media for rust removal?
- Which is the best sandblasting media for paint removal?
- Which is the best sandblasting media for glass etching?
- Which is the best sandblasting media for aluminum?
- Sandblasting media cost
- How to recycle sandblasting media?
- How to clean sandblasting media?
- How to dispose of sandblasting media?