You can turn a production knife into a one-of-a-kind piece after you practice using a high-speed rotary tool and the various bits available. This can add significant value if you are a merchant or you decide to sell your knife, unless you carve your name or initials into it. If you do, your potential sales will be limited rather than enhanced. If you practice on scrap material first, and graduate to inexpensive, bulk-purchase wholesale production knives, you will not destroy or waste valuable material. Once you gain confidence and skill, you can carve more expensive, single design knives to showcase your carving talents.
Start with scrap soft and hard wood. Use one bit at a time, making light and heavy grooves and swirls with each bit until you feel comfortable using it.
Carve one stroke at a time, pulling the tool across the scrap material with a smooth motion from top to bottom or side to side. Apply even pressure until you are able to make the cut the correct depth every time.
Wrap the edge of an inexpensive production knife blade with three layers of electrical tape in a spiral. This will protect both you from cuts and keep you from damaging the blade while carving.
Sketch your desired design on paper. Trace it onto your knife handle with a fine-point, black permanent marker.
Secure knife blade in a bench vise or hold it in your off hand. Begin making short, shallow cuts with your rotary tool and carbide burring tips. If a cut crosses from one material to another, such as from wood to brass, make the cut from the softer material to the harder one. Cutting from the harder material to the softer one will cause the burring tip to jump or score the handle deeper than you intended.
Continue until you have carved your desired design, stopping frequently to check progress. Change burring tips as needed.
Sad your handle with 120, 220 and 400-grit emery cloth and sanding sticks. Repolish any metal areas using felt bobs and polishing compound, using your rotary tool.
Wipe away excess buffing compound with paper towels. Remove electrical tape from blade. Dissolve adhesive by wiping blade with acetone. Repeat using penetrating oil and a clean rag.
Russell Scott advises, "Determine which direction the grain is running. You will want your carving cuts to go with the grain...Like using a spoon to scoop out melon balls, slice into the wood and come up and out at the end of the slice. If you do not cut out at the end of the cut, the wood may rip or tear. Your cuts may be short or long, as long as you do not tear away the wood. If the wood chip does not drop off by itself it is not cut all the way. Do not pull off chips as this may tear the wood ."
According to carver John Millar, when using a high-speed rotary carving tool, "...be aware that your hair can become wound around the working bit or collet, in an instant...Take care not to let your hair or any loose fabric come in contact with any rotating tool."