Sanding aluminum typically involves using progressively finer grits of sandpaper to smooth and prepare the surface.
To sand aluminum, you start with a coarser grit sandpaper and work your way up to finer grits. This process removes imperfections, scratches, and oxidation, leaving a smooth finish that can be further polished or coated.
Essential Steps for Sanding Aluminum
Sanding aluminum requires patience and the right materials. Here's a general outline of the process:
- Preparation: Ensure the aluminum surface is clean and free of grease or debris. You might use a degreaser or cleaner specifically designed for metal.
- Initial Sanding (Coarser Grits): Begin with a relatively coarse sandpaper grit, such as 180 or 220, depending on the initial condition of the aluminum. Use even strokes, either by hand or with a sanding block or orbital sander. The goal here is to remove significant scratches, pitting, or oxidation.
- Progressive Sanding (Medium to Fine Grits): Switch to finer grits sequentially. A common progression might be 400 grit, followed by 800 grit. As mentioned in the reference, 800 grit sandpaper is used, often after 400 grit.
- Each successive grit should be used until the scratches from the previous, coarser grit are removed.
- Sand in a different direction (e.g., perpendicular) to the previous grit's strokes to make it easier to see when the coarser scratches are gone.
- Finishing Sanding (Very Fine Grits): For a smoother finish, you can continue with even finer grits like 1000, 1500, 2000, or even higher, especially if you plan to polish the aluminum afterward. Wet sanding (using water or a lubricant with the sandpaper) is often done at these finer stages to reduce clogging and achieve a smoother result.
- Cleaning: After sanding, thoroughly clean the surface to remove all sanding dust and residue.
Recommended Sandpaper Grits for Aluminum
The specific grits you need depend on the starting condition of the aluminum and the desired final finish.
| Stage | Typical Grit Range | Purpose |
|---|---|---|
| Initial/Coarse | 180 - 320 | Removing heavy defects, oxidation, and paint |
| Medium | 400 - 600 | Smoothing the surface, removing coarse scratches |
| Fine | 800 - 1200 | Refining the surface, preparing for polishing |
| Very Fine/Polishing | 1500 - 3000+ | Achieving a high-polish shine (often wet) |
Note: The reference specifically mentions using 400 grit and then 800 grit sandpaper as part of the process.
Using the right sandpaper is crucial. Look for sandpaper designed for metal or suitable for wet/dry use, particularly for finer grits. Always sand in a well-ventilated area and consider wearing a dust mask and safety glasses.
