Here are some tips from an old time furniture restorer on how to remove a scratch on polished wood. Not for the faint hearted!
This procedure is recommended for deep scratches – minor ones can always be filled with wax. The assumption is that anyone embarking on this procedure should have basic DIY skills and not be a complete novice.
1. Float some plain water all along the ‘valley’ created by the scratch and wait for 30 mins or more for the water to penetrate the open grain (a result of the damage).
2. Heat an iron to max.
3. Place a sheet of newspaper along the scratch and follow the scratch with the tip of the hot iron pressing down gently so the tip ‘steams’ out the moisture through the newspaper. Use two sheets of newspaper to begin with.
4. This will have the effect of lifting the damaged grain to its original level.
5. Allow the surface to thoroughly dry out, and if necessary repeat the procedure until satisfied.
6. Apply matching stain carefully and sparingly along the scratch line with a very fine water colour brush.
7. Finish off with a generous application of wax which should be allowed to harden somewhat before finally polishing out.
I have witnessed quite deep scratches totally disappear using the above method. Just be careful not to linger too long in one place with the hot tip of the iron which could, if not accurately drawn along the scratch, damage adjacent surfaces.