Wet sanding is a method for removing scratches or minor defects in metal and painted surfaces. This method uses the grit from the sand paper which combines with water to form an abrasive slurry paste. An orbital sander is used to rub the paste against the metal surface to remove the defect or scratch. Wet sanding paper is different from regular sanding paper. Wet sanding paper has a heavy duty, fabric type backing to resist tearing. The fabric backing is able to absorb water without falling apart. By following the simple steps you can quickly wet sand most scratches or defects in metal to a smooth finish.
- Skill level:
- Moderately Challenging
Things you need
- Water spray bottle
- Clean rags
- De-greaser solution
- Various grits of Wet Sandpaper 180, 320, 400, 600 grit
- Orbital sander
Clean the area to be sanded thoroughly from any dirt and grease. First spray water on the afflicted scratch and wipe it clean. Then apply the degreaser, thoroughly wipe and rinse with the spray bottle water.
Attach the 180-grit wet sandpaper to the orbital sander and thoroughly spray the area to be sanded. Gently rotate the orbital sander over the scratched area. Be sure to keep the area wet as you work. Observe the amount of work the paste is doing. Once the major portion of the scratch or defect is removed stop sanding.
Clean the area again, first with the water to remove the majority of grit, then with the degreaser. The spot area should be thoroughly cleaned of all grit paste. You will find this is a repetitive process. The goal is to gradually remove the defect by sanding with progressively smaller grits to eventually polish the metal.
Attach the 320-grit wet sandpaper and repeat the method as in step two. Be sure to keep an eye on the progress of the sanding area. Your goal is to only remove the scratch or defect and not a heavy amount of the surrounding material.
Repeat the cleaning and sanding methods until you reach the 600-grit wet sanding paper. This grit will be the smallest in size. You may want to spend more time with the 600-grit wet sanding paper to give a high shine polish to the metal. Be sure to use plenty of clean water in order to keep a good paste consistency to the sanding area.
Tips and warnings
- Be sure to keep plenty of clean rags on hand. Never reuse the rag.
- This method can also be used to polish entire pieces of metal.
- Only use the clean surface of the rag to wipe the area so you do not contaminate the surface with the old heavier grit sizes. This will cause deeper scratches to the finished area.