Disclaimer: Please note that Graepels purchases their materials from material suppliers. The information provided here is intended as a guide to offer an overview of the materials.

What is meant by self colour?

‘Self-color’ metal refers to metal that is left in its natural, untreated state without any additional coatings, paints, or finishes applied to alter its appearance or enhance its properties. This approach takes advantage of the inherent characteristics and aesthetics of the metal itself i.e. retains its original look, showcasing the natural color, texture, and patina that develop over time.
No additional treatments are applied to protect the metal from corrosion, oxidation, or wear. However, it is possible to have clear finishes to preserve the ‘self colour’ but add additional protection. An example would be the use of lacquer.

Considerations for leaving Metal Materials in Self Color

Scratches and Damage: Self-color metals do not have protective coatings to hide scratches or abrasions. Any damage incurred during handling or transport will be visible and can impact on the overall appearance.
Protection Methods: Special care, such as using protective coverings or padding, must be taken to prevent surface damage.
Oxidation and Corrosion: Exposure to moisture or corrosive environments during transport can initiate oxidation or corrosion, particularly for metals like mild steel. This can prematurely alter the metal’s appearance.

Controlled Environment: Ensuring a dry, controlled environment during transport can help maintain the material’s pristine condition until it reaches its destination. This cannot always be guaranteed.

Minimal Surface Impact: The perforation process can mark sheets, minimising the impact on the surrounding metal surface to avoid distortions or marks that would be visible on self-color materials, would need to be specified by customer before manufacture.

Avoiding Contaminants: The weaving process should be free from contaminants that can adhere to the metal surface, especially since self-color metals will not have additional coatings to mask imperfections.

Welding and cutting processes can significantly affect the appearance and properties of self-colour metals. Considerations include:

Welding:

Heat Effects: Welding can cause discoloration, oxidation, and warping at the weld joints, which are visible on self-color metals. Proper technique and controlled heat input are essential.
Post-Weld Cleaning: Cleaning weld joints to remove any oxidation or discoloration without altering the natural color of the metal is crucial. Methods like pickling, brushing, or light grinding may be used.
Welding Consumables: Using appropriate welding rods or wires that match the base metal helps maintain consistency in appearance and corrosion resistance.

Cutting:

Cut Edge Quality: Cutting processes like shearing, laser cutting, or plasma cutting should produce clean edges with minimal burrs and oxidation.
Heat-Affected Zone (HAZ): Minimize the HAZ to prevent discoloration and maintain the integrity of the metal. Using waterjet cutting can eliminate thermal effects.

Please be aware that with all metal materials there are different Grades of material. For example, stainless steel has over 105 grades, the most common in industry and in manufacturing at Graepels are 304, 316 stainless steel. This table is meant as a general overview.