
How to Avoid Scratches When Using Coated Abrasives on Soft Metals

Soft metals, including copper, brass, and aluminum, are used in several sectors because of their qualities, which are corrosion resistance, lightweight, and conductivity. But because of their softness, they can easily get scratched during the cutting and finishing process. This can have an immense effect on how the final product looks and performs, mainly in situations where surface integrity and aesthetics are essential.
When it comes to finishing, polishing, and shaping metal surfaces, coated abrasives are essential. It includes sandpaper, grinding belts, and discs. They are perfect for removing material from the surface, but if not used correctly, they tend to cause scratches.
In this blog, we will go through the techniques for using coated abrasives on soft metals to prevent scratches.
Ways To Avoid Scratches On Soft Metals
Here are the techniques to follow in order to avoid scratches on soft metals.
1. Selecting the right abrasives
selecting the right abrasive is key to a scratch-free finish. It totally depends on the type of abrasive, grit sizes, and their backing material. Start by selecting the abrasive type. Aluminum oxide is mainly used for a variety of materials because of its adaptability and efficiency. Grit size is another factor to consider. To minimize the chances of deep scratches, use fine grit abrasives, especially for soft metals.
After selecting the grit size, choose a backing material, whether it is paper backing or cloth backing. When compared, both cloth backings are majorly used as they are highly flexible and produce fewer scratches.
2. Surface Preparation
the key to getting a scratch free finish is by carefully preparing and maintaining the surface. Start by cleaning the surface and removing contaminants like oil, dust, and grease for an efficient finish. Always clamp the workpiece properly or tightly to ensure that it will not move during the process. Also, examine the abrasives before using them to prevent any damage and defects. All these factors will generate a smooth or scratch-free finish.
3. Manage the speed and pressure
when working with abrasives, managing the speed and pressure is crucial for scratch-free finish, mainly for soft materials. Always make sure to apply even pressure to the abrasives. Avoid using too much pressure, which can cause scratches, in order to prevent them. Also, maintain a consistent speed during the process to avoid forming deep scratches. Always work in one direction to prevent cross-hatching.
Let the workpiece cool completely in between the process to prevent heat buildup, which softens the material quickly and makes it more prone to scratches.
4. Use lubricants
use good quality lubrication or coolants to prevent scratches. Coolants are based on the type of material you are working on. Water and oil-based coolants help minimize friction and prevent scratches.
5. Final details
make sure to use finer grits for a more detailed finish and remove any remaining scratches by using buffing wheels or polishing compounds. Also, keep an eye on corners and edges as they are highly prone to scratches.
6. Regularly maintaining your tools
ensure to regularly maintain your tools, including sharpening belts and sanders, for a more optimal finish. Also, examine your tools for any damaged or worn parts to prevent the workpiece from getting scratched.
By following the above-mentioned factors and understanding the properties of abrasives, you achieve a scratch-free finish on soft materials with high quality and aesthetics.