A serrated knife tends to be longer than a regular flat knife, and the sharpness is more difficult to restore without changing its shape. For this reason, it is best if a serrated knife is only sharpened when its effectiveness is visibly diminished. However, if you have more money, buy a serrated knife sharpener to solve the problem easily.
Step
Method 1 of 2: Using a Sharpening Rod
Step 1. Purchase a serrated knife sharpener
Serrated knives require a different sharpener than regular flat knives. Most serrated knife sharpeners are rod-shaped and are usually tapered to sharpen various sizes of serrations.
Step 2. Find the side of the knife with the beveled edge
Serrated blades are usually not the same from both sides. On the one hand, the angle on the face of the blade will remain the same until the blade eye. On the other hand, the blade face will be slightly angled down from the serrated edge; this model is called bevel. Sharpeners should only be used on beveled edges.
Step 3. Place the sharpening rod in one of the curves (“fan”) serrations
Selecting an angle on the serrated blade is easier because you can use the bevel angle as a guide. This angle is usually between 13-17 degrees from the blade, which is shallower than what is typically used for sharpening ordinary knives.
- If the knife also has a flat edge, the slope is usually at the same angle, about 20-25 degrees.
- If you want a better guide, scratch the edges of the curve using a permanent marker. You are sure to sharpen at the right angle if these marker marks are missing.
Step 4. Move the sharpening rod according to the diameter of the curve
If the sharpening rod is tapered, find a point on the rod that is the same diameter as or slightly smaller than the serration curve of the knife.
Step 5. Sharpen the curve of the first serration
Wipe the mounting rod along the first curve in a few short swipes. Press in one direction from the blade towards the back. Rotate the rod as you push it to increase friction.
Push only to the point of the rod that is the same diameter as the curve so that the serrations do not enlarge
Step 6. Check for the presence of “thorns”
Run along the back side of the curve with your finger to find any "thorns" or metal shavings. As soon as you feel the burr, you've sharpened the curve well. Usually only a few strokes are needed.
Try to feel along the back of the blade using your fingernail. If it feels stuck, it means there are thorns in the knife
Step 7. Continue to sharpen each recess in the knife
If the serrations vary in size, adjust the position of the sharpening rod so that it fills only the recess.
Step 8. Sand all the burrs
The thorns here are the metal shavings that appear when sharpening the blade. To get rid of it, rub the back of the knife with a fine grit sandpaper. Otherwise, you can rub the sharpening rod lightly against the back of each recess, being careful not to apply more pressure than necessary.
Step 9. Sharpen the flat part of the blade
If the knife is only serrated in one part of the blade, sharpen the rest with a sharpening stone or other tool. Do not use a serrated knife sharpener on a flat eye.
Method 2 of 2: Using Other Tools
Step 1. Use a triangular sharpener
Like a rod-shaped, this triangular sharpener is specially designed for serrated knives. Due to its shape, this tool is ideal for knives with a V-shaped recess. The process is almost identical to the bar sharpening method above, except that you are sliding the tool edge back and forth along the bevel instead of turning it.
Step 2. Make your own tool from emery and dowels
If you don't want to buy a knife sharpener, buy some cheap dowels from a hardware store. Find a dowel that fits the curve of the knife's first serration so it doesn't wobble, then wrap a piece of emery cloth over most of the dowel. Hold the fabric with your fingers, and grind it carefully and slowly. Change the dowel to match the size of the curve when working along the blade.
Use round dowels for round blades, or square dowels for V-shaped blades
Step 3. Sharpen with a square stone
This method is difficult and unreliable, but still possible in an emergency. Hold the back of the knife securely against a hard surface and tilt the blade so that the beveled edge is on top. Bring the corner of the whetstone to the serrated edge of the knife and use it to sharpen it, swiping back and forth to cover the entire area of each recess.
Tips
- Taking good care of the knife will reduce the frequency of sharpening. Knives should not be washed in the dishwasher or on a glass cutting board.
- Diamonds and carbides are the most aggressive sharpeners; it works fast, but a lot of metal is scraped off. Ceramic sharpeners and Arkansas stones (novaculite) are gentler on the blade, and are great for finishing touches on sharp edges.
- Clamp the knife in a vise to make the job safer and easier. This is even more important if you use an emery cloth as your fingers will be positioned close to the sharp edges.
Warning
- Compared to straight blades, serrated blades are more difficult to restore to their original state. If you want the perfect blade, it's best to hire a professional or send the knife to a manufacturer for re-sharpening. Fortunately, sharpening services are usually quite inexpensive.
- Even high-quality electric sharpeners usually have a hard time sharpening a full curve along the serrated blade. We recommend using the manual method.
