Metal surfaces can become coated with various contaminants and debris over time, making them difficult to paint or cover.
Grit blasting is a process that can clean and prepare any metal surface for coating, allowing you to achieve a flawless finish. In this blog post, we’ll discuss how grit blasting works and some examples of how it can be used to clean and prep metal surfaces.
Stay tuned!
How Can Grit Blasting Be Used to Clean and Prep Metal Surfaces for Coating?
Grit blasting removes mill scale from metal surfaces before coating or painting. It can also be used for corrosion, surface preparation, rust removal, and more.
So let us now discuss how! Grit blasting effectively cleans and preps metal surfaces so they are ready for coating. This can be achieved in a multitude of ways, as discussed below:
From Rough to Fine: Grit blasting can clean metal surfaces from coarse to very fine. This even includes deburring edges and hard-to-reach areas (such as inside holes in metal frames).
Removal of Mill Scale: Mill scale is a flaky layer that builds up on metal surfaces over time. This inhibits the life of any coating or paints applied to the metal surface. Grit blasting is an effective method for removing mill scale and includes a variety of abrasives that can be used for various applications and materials.
Corrosion Removal: Rust and corrosion can present a challenge to any coatings or paints that are applied to metal surfaces over time. This is again due to the flaking of the mill scale and the corrosion of the metal substrate beneath. Grit blasting is an effective method for removing corrosion and rust and can help achieve a flawless finish.
Descaling: Descaling is the removal of residues left by cleaning or etching. Grit blasting provides an effective method for descaling and can also be used to clean and prep for applying any coating.
Rust Removal: As mentioned previously, grit blasting is an effective method for the removal of rust and corrosion. This type of pretreatment can also include the removal of mill scale from ferrous metals such as steel and iron.
Surface Preparation: Grit blasting can also be used to smooth surfaces to prepare them for the application of a coating or paint. This can be achieved using specific applications and abrasives designed for specific applications.
These are just some methods in which you can use grit blasting for cleaning and prepping a surface so that it is ready to be coated or painted.
What Are Some Benefits of Using Grit Blasting to Clean Metal Surfaces?
When you use grit blasting to clean metal surfaces, you provide the surface with an even and smooth finish. This then allows for introducing a coating or paint to be processed and bonded to the metal surface more evenly than if the surface had not been cleaned by grit blasting.
Below we will list the top benefits associated with using grit blasting to clean metal surfaces:
- It removes rust and corrosion from metal surfaces.
- It prepares metal surfaces for painting or coating.
- It removes paint, grease, oil, and other contaminants from metal surfaces.
- It increases the adhesion of paint or coatings to metal surfaces.
- It allows the paint or coating applicator to see any rust and other surface imperfections that would not be visible otherwise, allowing them to be repaired before painting or coating the surfaces.
- It smooths rough or uneven surfaces of metal parts, which increases the ease with which these parts can be assembled and decreases the chance of damage during assembly or operation.
- It cleans and prepares all metal surfaces for bonding to plastics, woods, and composites, which increases the durability and longevity of these bonded assemblies.
These are the top benefits of grit blasting to clean metal surfaces before painting or coating them. As you can see, using grit blasting to clean metal surfaces is beneficial in many ways.
Is There Any Drawback to Using Grit Blasting to Clean Metal Surfaces?
You would be right to think that there are drawbacks to using grit blasting to clean metal surfaces. After all, we are talking about using abrasives that can damage metal surfaces if not handled correctly.
However, with some knowledge and experience in using and applying grit blasting on metal surfaces, these risks are minimised. They can be reduced even further by implementing proper safety practices when grit blasting metal surfaces and cleaning or prepping them in this way. Below we will list some of the drawbacks associated with grit blasting:
It Is a Messy Process:
Because grit blasting involves using abrasives to clean any surface, it can involve using large amounts of dust and water to clean up afterwards.
Therefore, if you are considering grit blasting as a form of surface preparation, you will need to consider the risk of this dust and other debris contaminating any surfaces that need to be coated or painted after the cleaning process is completed. However, this risk can be minimised with an appropriate dust collection system and adequate pre-cleaning processes in place.
It Can Create Sharp Edges:
Grit blasting can roughen the surface of any metal part. This can create sharp edges on the part that must be smoothed out either by filing or sanding before painting or coating the part.
However, with experience and the right tools, this risk can be minimised, and the part can be prepared for coating with sharp edges or rough areas, which is impossible if it has not been cleaned using this method first.
It Can Scratch Plastic Parts:
The abrasive materials used can scratch the plastic surface when grit blasting plastic parts. This can lead to visible scratches that must be smoothed out before painting or coating the part using plastic paints or coatings.
However, with experience and the consideration of which abrasives to use when grit blasting plastic parts, these risks can be minimised, and plastic parts can be cleaned efficiently and effectively.
These are some of the most common drawbacks of using grit blasting to clean metal surfaces before painting or coating them.
Suppose these risks are something that you would like to mitigate when grit blasting metal parts in preparation for painting and coating the surfaces. In that case, you should invest in the appropriate equipment for the process and train your staff on properly using that equipment. However, when properly used and with experience and training, grit blasting can be an effective cleaning process for preparing any metal surface for coating. It can provide a clean and smooth finish to metal surfaces, making them easier to paint and coat with flawless results.
What Coatings Can Be Applied to Metal Surfaces After Grit Blasting Them Clean and Prepped?
Metal surfaces can be coated for various reasons.
For example, if metal parts are being assembled or used in environments where the temperature of the metal parts rises above ambient levels or if parts are being used in environments where corrosive conditions are present, then these metal parts may be coated in a protective or decorative coating to prolong their lifespan and reduce the chances of damage or failure in those environments. Below we will list some coatings that can be applied to the cleaned surface of metal parts after grit blasting the surfaces to prepare them for painting or coating:
Paints:
Paints are one of the most commonly used coatings for protecting and decorating metal surfaces.
Paints are often referred to as enamels or varnishes, which is incorrect terminology as paints are not enamels or varnishes; they are solids that dry to form a film on a substrate. Paints can be made from various materials and can be solvent or waterborne.
Paints are more commonly used in applications where the lifespan of the coating is extended or where corrosion and paint wear are significant issues. Paints are also often used to increase the overall aesthetic appeal of metallic finishes without significantly reducing their functionality or lifespan.
Paints can be one colour or incorporate various colours or metallic finishes depending on the desired look and application of the part.
Epoxy Coatings:
Epoxy coatings can be one colour or incorporate various colours or metallic finishes depending on the desired look and application of the part.
Epoxy coatings are often used in applications such as the marine and automotive industries or in applications where high chemical resistance is required, such as in the oil and gas industries. Epoxy coatings can also be designed to impart specific properties to the coated substrate.
For example, epoxy coatings can be designed to impart high chemical resistance or high abrasion resistance to the substrate being coated. However, these types of coatings may sacrifice their aesthetics in the process.
Polyurethane Coatings:
Polyurethane coatings can be one colour or incorporate various colours or metallic finishes depending on the desired look and application of the part.
Polyurea coatings are often used in applications that require excellent chemical and abrasion resistance or must operate in corrosive environments. Polyurea coatings can also be designed to impart specific properties to the coated substrate.
For example, polyurea coatings can be designed to impart high chemical or abrasion resistance to the substrate being coated. However, these coatings may sacrifice their aesthetic properties in the process.
Rust-Resistant Coating:
Rust preventive coatings are often found on metal parts located outdoors in environments with significant moisture present in the air, such as the exterior of metal buildings or industrial properties.
Rust preventive coatings are also used on the exteriors of metal vehicles to protect them from corrosion and rust until the panels are repainted after some time. Rust preventive coatings can be applied to metal surfaces protectively or decoratively, depending on the type of primer used and the top coat applied on top of the primer and rust preventive coating.
A Primer
A primer is a coating used to prepare the substrate being coated for the top coat or finish that is applied onto the primer coat after the primer has dried.
The primer coat acts as a barrier to protect the substrate coated underneath the top coat or finish from corrosion and rust before the top coat is applied or the paint or primer dries. Primers are also designed to prevent colour fading or changing on some metal surfaces, especially during the priming process when a bright or shiny metal surface may become dull during the priming process due to the contact between water and the metallic surface being primed.
Primers may also prevent corrosion or rust from forming on their priming metal surface. They can therefore be quite helpful in protecting metal surfaces and prolonging their lifespans in corrosive environments or when exposed to moisture or moisture vapours.
Metallic Coatings and Powder Coatings:
Metallic and powder coatings can be one colour or incorporate various colours depending on the desired look and application of the part.
Metallic coatings and powder coats are used as an alternative to paint for metallic surfaces when the desired look of the part cannot be achieved using paint alone. These coatings can also be used to provide a different finish to the metallic part in question than the paint can provide, for example, a brushed or hammered metal finish instead of a shiny polished finish or to add a specific aesthetic or functional aspect to the part that cannot be achieved using paint alone.
Are Any Health and Safety Concerns Associated With Grit Blasting That Business Owners Should Be Aware of Before Starting the Process?
When it comes to applying paint or other coatings to metal surfaces, risks or issues can arise if the proper techniques are not applied, if they are not used properly, or if the process is rushed when preparing metal surfaces before painting or coating them.
Metals can be plated to provide electrical insulation or corrosion resistance or to enhance their aesthetic properties. However, the plating can be hazardous to your health if proper protection is not worn during the preparation and application phases, as plating fumes can be toxic and can cause irritation to the lungs or skin if the fumes are not properly ventilated out of the room or if the plating chemicals are used without proper ventilation or safety measures.
Fortunately for small business owners, when preparation methods for metals being used for plating or painting are followed properly and with the proper safety equipment or ventilation methods being used, the fumes associated with plating or painting can be minimal and non-toxic. However, if the proper precautions are not followed or the proper safety equipment is not worn during the plating or painting process. The fumes from the plating or painting chemicals are hazardous to your health.
Another health and safety issue that sometimes arises when preparing metal surfaces that will be used for plating or painting is that particles from the metal being removed or the metal being cleaned can accumulate in the air and become airborne if the area is not adequately ventilated. If inhaled, these particles can irritate the lungs or eyes or cause breathing problems if the particles become large enough to cause obstructions in the airways and the lungs.
Fortunately, these risks can be avoided by following proper cleaning and ventilation methods during grit blasting or metal preparation. Below, we will list some health and safety risks that business owners need to be aware of when preparing metal surfaces for plating or painting:
- Painting or coating fumes can be toxic if proper ventilation methods are not followed during preparation.
- Mineral particles can be released into the air during grit blasting or metal cleaning that can become airborne if proper ventilation methods are not followed during the preparation process.
- Particles from the complex metal significantly being cleaned or removed can accumulate in the air during the grit blasting or metal preparation process if they are not adequately cleaned or filtered out during the preparation process. If the particles are not properly cleaned or filtered out, they can become airborne and cause breathing problems or irritation to the lungs if inhaled.
- The noise generated by grit blasting or metal cleaning can irritate the ears and cause hearing damage if the sound is not managed correctly.
- The dust generated from grit blasting or metal cleaning can become airborne if proper ventilation methods are not followed during preparation.
As long as you follow procedures when preparing metal surfaces for plating or painting, then you should be safe and not experience any health problems caused by the cleaning process that you are using.
What Common Challenges Do Businesses Face When Trying to Clean and Prep Metal Surfaces for Coating?
Grit blasting and other types of metal cleaning processes can be very effective when preparing metal surfaces for coating and can also save business owners a lot of money in the long run.
However, business owners should be aware of some common challenges that can arise when trying to do this type of metal cleaning themselves:
- Preparing and grit blasting metal surfaces can be back-breaking work, especially when business owners are trying to apply the method to clean large metal structures or buildings.
- Metal structures or buildings with many nooks and crannies are challenging to clean using grit blasting alone because of the difficulty of reaching these areas with blasting media or grit.
- The grit blasting method can be rather painful and abrasive on the skin of business owners. It can irritate the skin if business owners are not wearing the proper safety measures and protection during the cleaning process.
- Business owners do not want to spend money on hiring professionals to spray or coat their metal structures or buildings if they know how to do this themselves.
However, business owners may find themselves spending more money in the long run if they can not adequately prepare their metal structures or buildings for coating or painting and end up having to pay professionals to fix any mistakes that they may have made by not properly preparing their structures or buildings for coating in the first place.
Although grit blasting and metal surface preparation may be difficult processes, business owners should be willing to shell out a little more money to hire professionals to spray or coat their metal structures and buildings when they think they may not be able to do so correctly themselves.
Who Should Use Grit Blasting to Clean Metal Surfaces?
Small business owners who own and operate their metal structures or buildings and are looking for an excellent alternative to using chemicals and paint on their metal structures or buildings should consider grit blasting.
Cleaning and grit blasting metal structures or buildings can eliminate any water or rust stains on their metallic surfaces and give them a gleaming and new appearance as if they have just come out of the factory or been freshly painted. When business owners use grit blasting to prep their metal structures or buildings for coating or painting, it improves the look of the metal. It removes any rust or paint that may have formed on the metal before coating or sealing the metal structure or building.
Business owners who utilise this pre-prep method on their metal structures or buildings will find that the coating or paint will last longer on these structures, or buildings, especially if any of the metal structures are exposed to the elements regularly.
Conclusion
Grit blasting is a versatile process used to clean and prep metal surfaces for coating.
There are many benefits to using grit blasting, including increased efficiency and better results. However, there are also some drawbacks to considering starting the process.
Businesses should weigh the pros and cons of grit blasting before deciding whether it is the right solution. Contact us today if you’re looking for a reliable way to clean and prep metal surfaces for coating.
We have years of experience with grit blasting and can help you determine if this is the best option for your business.