Brushing Surface Finish: Complete Guide

The metal brushing surface treatment process creates a fine and uniform texture on the metal surface through mechanical or chemical methods, which not only enhances the tactile feel of the material, but also adds a unique visual effect to it. Are you interested in brush surface preparation tools, techniques and practical methods? This guide will provide you with comprehensive and in-depth information.

What is the Brushed Metal Surface Finishing Process?

Brushed metal surface treatment is a method of using mechanical tools to produce fine textures or lines on the metal surface. This process not only brings a unique visual effect to metal products, but also improves the durability and functionality of its surface, improving the overall quality of the product.

Detailed Explanation of Brush Finishing Process.

The brush finishing process generally includes the following steps:

Surface Preparation:

Before applying a topcoat, the surface needs to be carefully prepared, including removing dust, oil and rust, repairing cracks and holes in the substrate, and sanding and polishing as appropriate to improve paint adhesion, especially for materials such as brushed metal, brushed steel and brushed aluminum.

Apply Primer:

The main function of primer is to enhance the adhesion between the coating and the substrate and to improve the weather resistance, corrosion resistance and other properties of the coating.

According to the type of paint and the characteristics of the substrate, choose a suitable primer for painting.

Apply Topcoat:

According to the design requirements, select the appropriate topcoat for painting. The number of times the topcoat is painted depends on the performance of the paint and the decoration requirements. Generally, 2-3 times are required. During the painting process, pay attention to the uniformity, glossiness and thickness of the paint to avoid defects such as sagging, bubbling and missing paint.

Later Steps:

After brushing, the coating is trimmed to remove excess paint and imperfections.

According to the drying time and curing conditions of the coating, carry out necessary maintenance to ensure that the coating achieves optimal performance.

Advantages of Brushed Finishes.

1. Strong Construction Flexibility

The brushing technique has remarkable versatility and is not constrained by the construction environment. It can effortlessly handle substrates

with a variety of complex shapes and structures, including corners, narrow regions, and other difficult-to-reach areas.

2. Significant Cost-Effectiveness

Compared with other brushing methods such as roller brushing and airless spraying, brushing can more accurately control the amount of paint used and reduce waste. It is especially suitable for brushing small areas or complex surfaces.

3. Good Decorative Effect

The brushing process, with its unique delicacy, can create a uniform and smooth coating. By controlling the brushing force and speed, the thickness of the coating can be flexibly adjusted from light to moderate to meet different decorative needs. At the same time, brushing can also give the coating different glossiness, from matte to semi-gloss, to shimmer, creating different visual effects.

What Materials Can Be Brushed?

Brush coating technology has shown a wide range of application potential in metal surface treatment, especially suitable for a variety of metal materials such as stainless steel, aluminum alloy and iron. These metal surfaces are often imperfect due to scratches, oxidation or natural wear during the manufacturing process, and the brush coating process can effectively solve these problems.

Stainless steel: Brushing can not only cover minor flaws on its surface, but also give it a richer color selection by choosing the right paint, from classic silver to deep black, and even bright colors, which can be easily achieved, greatly improving the visual effect and decorativeness of stainless steel products.

Aluminum alloy: By brushing, a protective film can be formed on the surface of aluminum alloy, which effectively prevents oxidation and corrosion and prolongs its service life. At the same time, brushing can also add a unique gloss and texture to the aluminum alloy.

How to Brush Metal Surfaces

Pre-Brush Stage

Clean the metal surface with an industrial degreaser to remove grease and dirt. Check for and repair any scratches or dents. Keep the metal temperature between 15°C and 25°C.

Brushing Stage

Apply steady pressure and brush in a fixed direction to create a matte brushed effect on metal surfaces. When brushing stainless steel, hold the brush at a 45-degree angle to the grain. Control the brush speed between 1,500 and 2,000 RPM and adjust the brushing time according to the effect.

After Brushing

After brushing, clean the metal surface with a non-abrasive solvent to remove any residue. Check for texture consistency. Passivate if necessary. Perform a visual inspection and surface roughness test to ensure quality.

Factors Affecting Brushing Finishing Quality.

There are many factors that affect the quality of brush finishing. These factors run through all aspects of the brushing process, from material selection, surface treatment to construction operations, and will have an important impact on the final brushing effect. The following are some of the main influencing factors:

1. Material Factors

Paint quality: The type, performance and quality of paint directly affect the painting effect. High-quality paint has good adhesion, weather resistance, wear resistance and decorative properties, which can ensure that the coating after brushing is uniform, smooth, beautiful and durable.

Diluent selection: The type and amount of diluent have a direct impact on the viscosity and fluidity of the paint. Improper selection of diluent or improper dilution ratio may cause the paint viscosity to be too high or too low, thus affecting the brushing effect.

2. Surface Treatment Factors

Cleanliness: The surface of the metal or other object to be coated must be thoroughly cleaned to remove impurities such as oil, rust, old coatings, etc. to ensure that the paint can adhere firmly to the substrate.

Roughness: Appropriate surface roughness can increase the adhesion of the coating. However, too much or too little roughness is not conducive to the adhesion and appearance of the coating.

3. Construction Operation Factors

Construction technology: The technical level of construction workers has an important impact on the quality of brushing. Skilled construction workers can master the correct brush painting methods and techniques to ensure that the coating is uniform, smooth, and free of brush marks and bubbles.

Construction tools: Choosing the right construction tools is also the key to ensuring the quality of brush painting. For example, for different coatings and substrates, you need to choose brushes or spray guns of different materials and models.

4. Other Factors

Paint ratio: The paint ratio must be accurate, otherwise it will affect the performance of the paint and the painting effect.

Drying time: Each coating has its own specific drying time. If the coating is not completely dry before the next process, it may cause blistering, peeling and other quality problems.

Comparison of The Finish to Other Metal Finishes.

When choosing the most appropriate metal surface treatment for a project, it is important to understand the characteristics of various processes and their impact on the success of the metal machining project. The following is a comparative analysis of wire drawing surface treatment and several common metal surface treatment methods:

Brushed vs Mirrored Finishes

Visual Effect: The brushed surface gives the metal a fine, directional, satin-like texture, while the mirrored surface is highly reflective, emphasizing its smoothness and glossiness.

Surface roughness: The average roughness of the brushed surface is 0.2 to 1.0 microns, which makes it less susceptible to scratches and fingerprints than a mirror surface.

Comparison Between Brushing and Polishing

Smoothness and reflectivity: Polishing produces a smoother and more reflective surface than brushing, with Ra values as low as 0.01 microns. However, brushing has advantages in cost-effectiveness and processing time.

Suitability: Polishing provides the ultimate in gloss, but brushing is more desirable in many applications due to its economy and efficiency.

The Difference Between Brushing and Sandblasting

Surface texture: Sandblasting creates a matte surface through high-pressure sand impact, with a higher Ra value (1.6 to 3.2 microns), giving the metal stronger anti-slip and anti-fingerprint properties. Brushing focuses on delicate linear textures and is more aesthetically pleasing.

Corrosion resistance and strength: Shot blasting increases the corrosion resistance of metals but may reduce their fatigue strength. In contrast, wire drawing has less effect on strength.

Comparison Between Brushing and Anodizing

Anodizing is an electrochemical process that forms a protective oxide layer on the metal surface, significantly increasing its hardness, while brushing is a mechanical process that physically creates a specific texture on the metal surface.

Application of Brushed Finishes.

Wire drawing surface treatment is a versatile technology widely used in various industries and is suitable for a variety of processing needs. Its characteristics are that it can flexibly respond to different scenarios and achieve the following effects:

Edge Blending: Effectively smooth the edges of metal parts to achieve seamless connections between different surfaces, especially suitable for fields with high precision requirements such as defense and aerospace.

Deburring: As an effective method for removing sharp edges and minor imperfections on mechanical parts, wire drawing can significantly improve the quality of components and is crucial to the safety and reliability of industries such as automotive and aerospace.

Roughening: Brushing can increase the roughness of the metal surface. This change enhances the adhesion of paint or other coatings, while making the surface easier to clean, improving the durability and maintenance of the product. In the automotive industry, this is often used in the preparation stage before painting.

Cleaning: Wire drawing can effectively remove rust, oxides and pollutants on the metal surface, restore its original gloss and cleanliness. It is particularly suitable for fields with high requirements on cleanliness, such as medical device production and marine environment.

 In Conclusion

As an important method of metal surface treatment, brushed surface treatment technology is unique in that it can improve the appearance and actual functionality of the product at the same time. Compared with other surface treatment technologies, brushed treatment not only gives the metal surface a low-key and elegant visual effect by forming delicate textures or lines on its surface, but also enhances the surface’s wear resistance and anti-fingerprint performance, reflecting the harmonious unity of practicality and beauty.