The Comprehensive Guide to Powder Coating Aluminum

Aluminum is the most sought-after material for building various structures. 

Being durable and lightweight, this metal does the job just right. 

However, its durability, longevity and appearance can be enhanced by choosing the right finish. 

Nowadays, powder coating has gained a lot of popularity making it a desired finish. If you are new in the world of finishings and are unaware of what powder-coating aluminum is, then you are at the right place. 

This article will take you through the entire process of powder coating along with its benefits, making you realize the utmost importance of powder coating your aluminum pieces. Let’s get started! 

• What does Powder Coating actually mean?

The process of powder coating involves a dry powder that is used as a finishing material. 

This powder is applied to the metal surface followed by baking the metal to make sure the protective layer is firm enough.

 You can powder coat any material including aluminum. There is also a wide selection option of colors to powder coat aluminum, such as clear, white, black, brown etc.

 This process elevates the appearance of the metal by giving it a matte or glossy look while increasing its life.

 If it is done accurately, you won’t have to worry about protecting your aluminum products from the damage caused by wear and corrosion. 

• Powder Coating  Types

Horizontal Powder Coating

Horizontal powder coating means the application of coating powder to a surface placed in a horizontal orientation.

The horizontal powder coating involves 2 shifts, making the whole process take around 48 workers. The production capacity of horizontal powder coating is only 500 metric tonnes of aluminum.

 This process involves six steps, making the production process complicated. The only advantage it has is the low equipment investment. 

Vertical Powder Coating

Vertical powder coating means spraying the powder to coat a surface placed in a vertical orientation.

The vertical powder coating cuts down extra time taken along with the labor. This process takes only 24 workers and is able to cater to around 1500 metric tonnes of aluminum.

 The production process is also simpler, involving just three steps. The only drawback of this process is its high investment in equipment. 

• Different way to powder coat aluminum

To powder coat aluminum, there are many types of  finishings and processes that can be used. Below we have gathered some of the best ways to powder coat your aluminum products: 

Polyester

One of the most popular choices for powder coating is polyester. 

The process simply involves an electrostatic spraying of electrostatically charged powder. This makes the polyester particles stick to the metal.

However, there are two types of polyester powder coatings available in the market currently. The first is the triglycidyl isocyanurate (TGIC) and the other, most preferable one is the TGIC-free. It is liked because it offers an ideal consistency and is much more suitable for large-scale production usage.  

Super Durable Polyester

This type of coating utilizes a type of polyester which is a bit more sturdier than the normal ones. 

There are many pros that come with the utilization of super durable polyester for coating your aluminum products. Firstly, it protects against rust. 

Moreover, it also shields the metal from harmful UV rays. Its longevity sets it apart – it can outlast regular polyester by up to ten years. 

If you’re after a sleek, glossy finish, particularly for outdoor structures like window frames or roofs, this will be your best choice. 

Epoxy

Epoxy is slightly more expensive than the other coatings. However, it is extremely durable and tough. 

If your aluminum pieces are exposed to heat or extreme environmental conditions, use epoxy to coat them. It also takes care of the aesthetics with a wide color range.  

Fluoropolymer

This is the top-tier, the priciest, but also the sturdiest. It’s reserved for products that’ll be up against severe temperatures or conditions. 

With fluoropolymer, the color options are fewer but can be tailored as per your demand.

Urethane

This coating is similar in strength to epoxy, but it’s especially useful outdoors. It’s a popular pick for items that need to resist chemicals, from car parts to doorknobs. One cool feature is that dirt and stains don’t show up easily on it. 

However, there are some downsides. It can be costlier than epoxy and might not be the greenest option due to the fumes it releases during its application.

In essence, the right powder coating depends on your needs, whether it’s longevity, aesthetics, or resilience against the elements. Each category from the above holds its unique strengths and uses.

• Powder Coating Aluminum Advantages

Aluminum has a natural ability to resist corrosion. However, in some circumstances, it seems necessary to powder-coat aluminum to provide extra protection.

Powder coating of aluminum can help you prolong the life of many things for example playground equipment, and sign boards. 

Let’s go through the top six reasons why you should be using powder coating as a finishing process: 

1-Corrosion resistance

By powder coating aluminum you provided your product with added protection against corrosion.

The metal base is safeguarded against oxidation and other forms of severe weathering. This increases the durability and the longevity of your product. 

On top of this, the powder coating also provides a scratch-resistant thick layer. This also helps in protecting against stresses that can cause the product to wear out.

2-Wide color selection option 

The choice of colors for powder coating is immense. You can pick any color you like. There are many variations available too, including, matte, gloss, and wrinkle.

These colors are resistant to fading along with providing your product with UV protection. Hence, this makes powder coating ideal for achieving an aesthetic finish. 

You won’t have to renew the color for up to 20 years despite the tough environment you expose the product to. 

3-Minimal wastage

Powder coating is sprayed on the parts and whatever is oversprayed can easily be collected. This allows it to be reused. 

The ability to reuse powder coating allows more parts to be covered. This helps you minimize the wastage. Hence, you can benefit from a cheap finishing process. 

4-Environmentally safe

The process of powder coating is environmentally safe. It doesn’t involve volatile organic compounds like those present in the paint. There are no carcinogenic or other toxic compounds. Hence, it causes no harm to the technicians during the application process. 

• Aluminum Powder Coating Process

If you are wondering how the process of aluminum powder coating takes place then here are the five basic steps involved in the process. 

1. The pre-treatment:

The pre-treatment is a bath that involves the removal of all the unwanted particles. This is essential to get rid of the dust and grease. After this, your product has a clean surface. 

2. Powder paint adhesion:

It involves spraying electrostatically charged powder paint on your aluminum products.

The positively charged powder binds with the electrically grounded profile. This step takes place in a spray booth. 

3. Curing or baking:

This step involves baking the aluminum product by passing it through a curing oven.

The coated powder paint adheres to the aluminum products. You also get an even coating through this step. 

4. Cooling:

After the process of curing the aluminium products require cooling. Once they have cooled down, an inspection is done. This ensures that the paint is evenly spread. 

There are many tests like scratch test, punch test, and microns test carried out. They check the surface thickness and adhesion of the paint. This helps in maintaining the quality of the coating. 

5. Protection and inspection:

Finally, another layer of protection is added to the aluminum product. It is fed through a machine in which protective films attach all of its sides. 

This prevents the powder from peeling off and makes your product scratch-resistant. Hence, it can be safely delivered to you without any damage. 

These are all the simple steps involved in the aluminum powder coating process. 

• Global Top Paint and Coatings Companies Wellste Cooperate

Number 3-Akzo Nobel.

A Dutch multinational company that is famous around the globe for creating paints and performance coating for industrial and consumer use.

From its headquarters in Amsterdam, it has become the world’s third largest paint manufacturer. 

Number 2-Jotun

This is a Norwegian multinational chemical company. Being the largest manufacturer it provides decorative and performance paints and coatings.

The company focuses on constant innovation and creativity to stay up to date with the changing trends.

Number 1- PPG

This American company is a global supplier of paints, coating, and other materials. It has been named among the top 500 American Fortune companies.

 It functions in 70 countries making it famous for its high-quality products. This is why it has become the world’s top coating company.  

• What makes Powder Coating a better option as compared to Anodizing And Paint?

Anodize:

The process of Anodizing involves an electrolytic passivation procedure. You can use it to thicken the metal’s natural oxide coating. 

Using this procedure the metal becomes more resistant to corrosion and wear. You also get an adhesive surface which can be used for paint primers and adhesives.

This method is liked because of its ability to provide your product with an enhanced aesthetic effect. You can get a distortion simply by reflecting light on it. 

To anodize aluminium you can utilize Sulphuric acid. This provides you with a porous surface, making the dying process easier. You simply have to apply a sealer after the color application. 

However, you are offered a limited range of color selections. This is because the final shade depends upon the alloy base. 

Paint:

Paint is widely used as a finishing material because it’s accessible and cheap. 

When choosing paint as a finishing product for aluminum components you need to keep the environmental risks in mind. 

The harsh chemicals filled in the paint are considered carcinogenic. They are also combustible, placing you in danger of a fire hazard. Paint usage is a significant factor in the contribution of ozone layer depletion. 

Furthermore, paint gets wasted more owing to evaporation. You cannot gather it and use it again. 

Powder coating:

The process of powder coating involves spraying an electrostatically charged colored powder over a material. 

For aluminum, this procedure has many benefits. There is little wastage as the excess spray is easily collected for reuse. You will also enjoy a less hazardous environment because the powder coating lacks any solvents. 

Despite being a new method introduced in the market, powder coating has left a lasting impression. If you seek aesthetics, durability, and sustainability then choose this method. It is also suitable for many aluminum products like windows, railings, and roofing. 

The finished product:

All the finishing methods that we have covered above have their own perks and drawbacks. However, powder coating proves to be the only option whose advantages outweigh its disadvantages. 

• How does Wellste control the powder coating quality? 

At Wellste corporate, our utmost priority is to provide high-quality powder coating. We do this by utilizing a highly effortful process of inspection called Cross-Cut Testing. In easier words, it means paint adhesion testing.

The process of cross-cut testing involves making small cuts through the coating layer. This allows us to inspect how the adhesion and coverage have taken place. 

This method comes with the advantage of ensuring the detection of any issues in the quality. Our team can efficiently identify insufficient coverage, adhesion problems, and many other defects. 

Furthermore, the cross-cut testing helps us in meeting the desired standards of coating. We need to make sure we coat your products in a way that they are highly resistant to corrosion. 

Our entire focus is to make your product more durable and appealing. Hence, we prioritize our quality control at all times. 

• Powder coating defects and causes

Here are some common defects that cause imperfections in the coating: 

1-Defects caused by burrs

When the oxide skin is not removed properly large burrs form. Aluminum material also gains flaws when it is insufficiently heated. Pre-treatment fails to remove many of these particles because they are very tiny. 

To remove these flaws, aluminum products are brushed and cleaned before the pre-treatment. An alkaline etching tank also ensures the removal of such defects. 

2-Defects caused by aluminum chips

It is difficult to remove the aluminum chips as they aren’t blown away easily. During the washing, they may stick to the aluminum surface. 

These big flakes result in projecting particles during coating. Hence, it is vital to take these flakes off before the coating process. 

3-Defects caused by coolant

If the operator fails to clean the coolant off the aluminium then the coolant will dry to form glue spots. It cannot be removed by pre-treatment. 

This causes the coating particles to spread densely. To remove this defect you can use small clips to clamp the labels. 

4-Defects caused by dust

A layer of dust can settle on the aluminum surface. If it is not cleaned then the paint will become dense and uneven.

These hard particles can also scratch the coating. Hence, to remove these large particles, aluminum should be covered with a cotton cloth temporarily to prevent dust from settling. 

5-Defects caused by cotton

There can be linear defects caused by filaments from cotton work clothes and cotton threads. These burrs make the coating defective. Hence, the operators are required to wear rubber or canvas gloves which don’t produce filament.

6-Defects caused by Hanger’s poor cleaning 

It is important to clean the hanger with compressed air to remove the paint slags, iron powder, and even debris. This will ensure good electrical conductivity for coating. 

7-Defects caused by powder quality

The temperature of the powder should be lowered before packing. If not then larger pieces harden making the powder coating perform poorly. Hence, it is important that you pick a powder that is reputable and check it using a mesh screen.

Conclusion

In conclusion, powder coating is the best choice when selecting a finish to protect aluminum surfaces. This will add shine to your aluminum products while increasing their durability and longevity. This process is also safe for the environment, making it more desirable.

However, it is important to properly prep and clean the aluminum before powder coating it. By this, you can prevent the drawbacks associated with powder coating.

To ensure your aluminum products are properly powder coated, make sure you choose a reliable service company.