How to polish aluminum?

Want your aluminum to shine like a mirror?

Then it’s good to know that not all aluminum alloys are the same.

First, you need to understand what type of alloy you’re about to polish — a soft or a hard aluminum alloy. How can you tell the difference in simple terms?

Soft alloys are usually non-load-bearing — decorative trims, handles, fittings, or accessories.

Hard alloys, on the other hand, are structural and must meet certain strength requirements to withstand stress — for example, suspension arms, rims, or construction components.

Be careful when working with soft alloys and thin sheets. They tend to warp when heated, so it’s important to keep that in mind. To prevent distortion during polishing, cool the material regularly — either with a ventilated or pleated polishing wheel, or by keeping a bucket of cold water nearby.

The hardness of the material determines which polishing wheel you should use. The softer the aluminum, the softer the initial polishing wheel should be (for pre-polishing). Conversely, the harder the alloy, the harder or impregnated the wheel needs to be. That’s why there are so many different fabric types used for polishing wheels. To give you an idea — hospital sheets are considered relatively hard fabrics, while flannel belongs among the very soft ones.

Let’s make it clear:
For hard alloys, use hard fabric wheels or impregnated ones (for example, orange or yellow wheels available on my e-shop).
For soft alloys, use soft fabrics.

Both types of alloys share one common rule: as you move toward the final polishing stage, the fabric must get progressively softer. Only the hardness of the fabric changes — depending on the hardness of the aluminum being polished.

In summary:

• The softer the alloy → the softer the polishing wheel.

• The harder the alloy → the harder the fabric you should use.

• The closer you get to the finish → the softer the material should be.