Removing scratches from an optical glass sculpture can be a delicate process. Depending on the depth of the scratch, you may need to start the full grinding and polishing process again.
Here are a few steps you can try to remove scratches from optical glass:
Clean the surface
Begin by cleaning the sculpture with a mild glass cleaner and a soft, lint-free cloth. This will remove any dirt or debris that could worsen the scratches.
Assess the depth of the scratch
Examine the scratch closely to determine its depth. If it’s shallow, you may be able to remove it by polishing the area. Deeper scratches may require you to repeat the full grinding and polishing process.
Use a glass polishing compound
For shallow scratches, apply a small amount of cerium oxide to the area. The most effective method is using a handheld polisher with a felt pad. Mix a small amount of cerium oxide with water (a good ratio is 2 parts cerium oxide to 1 part water).
Apply a tiny amount of the slurry paste to the scratch—or directly onto the pad—and polish in a circular motion or alternating vertical and horizontal movements. Use just a small amount of paste to target the area. (Keep water to a minimum, especially when using an electric tool.)
Repeat the process until the scratch begins to fade—this may take 5 to 20 minutes, depending on its severity. If the surface starts drying out, spray it lightly with water to keep the compound active. Be patient and apply gentle pressure while polishing, but avoid excessive force or overheating the area, as this could cause further damage.
Rinse and inspect
Once you’ve finished polishing, rinse the area with water and dry it using an air compressor or a clean cloth. Inspect the sculpture under proper lighting to see if the scratches are gone. Repeat the process if needed. Removing a scratch can take time, so patience is key.
Go back to grinding (if needed)
If polishing doesn’t yield satisfactory results, the scratch may be too deep. You’ll likely need to return to earlier grinding stages using silicon carbide or diamond pads, and work through the steps again until you reach the cerium oxide stage.
Watch how I do it with a handheld polisher and felt pad → Watch on Instagram