In this video, Brian shows viewers how to polish the metal parts on a pocket knife. To do so, you will need a bench grinder with buffer attachment and some wd-40. Use the softer side of the attachment and set it to about 5 pounds of pressure. To get started, turn the grinder on and spray the wd-40 on the attachment while it is spinning. Then, run the metal parts of the knife handle over the spinning attachment. Next, use a lint-free cloth to "buff" the finish to remove the black residue from the grinder and w-40. You can also polish the blade in the same fashion, being careful to hold on to the handle tightly so it will not slip.