In many instances, you can repair light scratches in tempered glass. There are compounds specifically made for the job and others that can be found in many homes that will also work. By diligently rubbing the compound of your choice over the scratched area, you may avoid the substantial cost of replacing glass and return it to its original beauty.
Inspect the scratch to see how deep it runs. If your nail catches in the scratch, your best course of action is to have a professional take care of the scratch as it may be too deep.
Clean the scratch and the surrounding area to remove any dirt or debris in the area you wish to repair. You can use glass cleaner and a clean rag to do so, but make sure that the area is properly cleaned.
Place a small amount of tooth-whitening toothpaste on a clean cloth and rub over the scratch in a circular motion. The grit that is contained in the toothpaste may be just strong enough to buff the glass and get the scratch out.
Clean the area after you have rubbed for a few minutes to see what has been accomplished. If the scratch still remains, but has improved, use an orbital sander with a soft cloth attached on medium speed to buff it out. The sander will add additional pressure and consistency and may finish the job that hand rubbing was not able to complete.
Use jeweller's rouge, which is a compound used by jeweller's to polish precious metals such as gold and platinum to remove the scratch if the toothpaste method was ineffective. Mix it with glycerine for best effect and gently rub onto the scratch and try not to apply too much pressure as to break or damage the glass further.
Allow the compound to dry on the scratch for 30 seconds and carefully remove with warm soapy water on a rag, repeat the process if necessary.
Do not apply too much pressure with the sander or while rubbing by hand as it may break the glass if the scratch has caused structural damage.