Tips for Sharpening Fillet Knives
AFTCO Fillet Knives have quickly become a staple in the tackle bags of all anglers. Whether on your camping trip filleting walleye or perch or offshore breaking down a large tuna or swordfish, the AFTCO line of fillet knives is perfect. Now available in five models: the standard 8”, 10”, and 12” lengths, and a flex series in 7” and 9”. But, when you have this knife at home, how do you ensure it stays sharp enough to break down your catch properly?
Do I Need To Sharpen My AFTCO Fillet Knife?
AFTCO Fillet knives are made with Boker 4116 Stainless steel featuring a 56-58 on the Rockwell Hardness scale. This makes our fillet knife a soft steel knife. Soft steel knives are made of German stainless steel and are perfect for flexible knives cutting through small bones like an AFTCO fillet knife. You want a soft knife to reduce microchips in the knife when hitting rib bones or backbones in a fish. The smooth steel's edge rolls, saving the knife from breaking. Because the edge rolls, it requires consistent honing. Honing a blade takes that rolled edge and brings it back to a straight edge, making it sharp again. When honing a knife, you are not sharpening the knife but reshaping the edge.
We recommend honing a blade at least every day you use the knife, but to ensure the sharpness, it's best to hone your AFTCO fillet knife before every single large fish. If your knife does not get honed often, the blade will continue to roll more and more, making your knife feel dull. Once it is rolled too far, no amount of honing will reshape the edge, and you will have to sharpen the blade, creating a new edge. Aside from honing, we recommend sharpening your AFTCO knife at least once a year or more if you use it frequently.
How to Hone a Knife
There are many techniques to hone a knife. One method we found useful is placing the tip of the honing steel on a towel to prevent slipping. Then, place your knife at a very slight angle to the honing steel. In a downward motion with light pressure, swipe down, running the whole blade along the steel. Make sure not to forget the tip. Do this on each side equally, approximately 8-10 times. With experience, you will become faster and learn how you prefer to hone your knife.
How to Sharpen a Fillet Knife
Your knife will need a true sharpening once a year, or sometimes more, depending on use. This requires a sharpening stone of some sort. The best fillet knife sharpeners use water stones, also known as whetstones and oil stones. We like to sharpen our AFTCO knives with whetstones.
1. Select Your Whetstone
Start by choosing the whetstone or sharpening stone you will be using. When knives get very dull and have microchips, they require a coarser gritstone to create a new edge. Think about sandpaper, and the same method applies. We start with a coarse grit, such as 300 or 400, to create a new edge. After that, 3000 to 8000 grit is considered fine grit and best for polishing the blade and honing. If you want to use only one stone, a 1000 medium grit stone is recommended.
2. Prep Your Whetstone
Once you have your sharpening stone, you may need to soak it in water for at least 20 minutes (preferably 30 minutes). If you bought a “splash and go” stone, you can skip that step. Once you have soaked or prepped the stone, it's time to get started.
Once you have your sharpening stone, you may need to soak it in water for at least 20 minutes (preferably 30 minutes). You can skip that step if you bought a "splash and go" stone. With the stone prepped, it's time to sharpen.
3. Sharpen Your Fillet Knife On The Whetstone
The one thing you need to ensure you get right when sharpening fillet knives is keeping a consistent angle on the blade as you sharpen. A good tip to know is that a good angle is to place two quarters on your sharpener and lay the top of the knife on the edge of the quarters. Once you remove the quarters, keep that angle as you start sharpening.
A good way to think about it is to sharpen your knife in the direction you normally use it. For example, since we slice by pulling with a fillet knife, we should sharpen it in a pulling motion. If you use knives to chop and typically make a pushing-down motion, you should sharpen them in a similar pushing motion to a downward chop.
Start with a coarse or medium gritstone and hold the knife in your dominant hand. If you are sharpening the 8″, 10″, or 12″ fillet knife, place three to four fingers of your secondary hand on the blade to apply pressure. If you are sharpening the 7″ or 9″ flex blade, use two fingers since the blade is thinner, and make sure to hide any other fingers so they are not open to an accident. Using a slicing motion, run the blade from heel to toe, ensuring you sharpen the whole blade. Count the number of times you make the slicing motions.
Make sure to use a base for the stone that has traction, or put a towel underneath the stone to ensure it does not slip. This is extremely important because slipping can mean cutting yourself. You may need to adjust you position a little at the tip to make sure the entire knife gets sharpened.
4. Flip Your Blade & Sharpen The Other Side
After making a few sharpening motions on the stone on one side, flip to the other side of the blade and try to keep the same angle you initially used. Repeat the number of strokes you had made previously.
Once you have done the first set of sharpening, you can carefully rub your finger down and away from the cutting edge to feel for a burr. The burr tells you that you have created a new edge, and you are ready to move on to the next stone. If you do not feel the burr, that is okay. Continue doing the previous motions in increments of 10 sweeps until you feel a noticeable burr.
Whether you go from coarse to medium or medium to fine, complete the same motions for another 30 to 40 strokes on each side.
5. Switch to Your Fine-Grain Sharpening Stone
Now that you are on the fine grain, you will polish the stone. Since the grain is so fine, it polishes the blade when you strop it. Think about old-time westerns where the cowboys used their leather belts to strop their knives. Same thing! But with a polishing stone.
You can do the same motion with your fine-grain stone, ensuring you make contact with the whole knife. However, only do it in one direction. Start with 10 strokes on each side, then 8 strokes on each side, then 6, 4, 2, and then do one stroke on both sides multiple times. Along with polishing the knife blade, you are also taking off the burr to leave only a precision-sharp knife once you are done.
6. Test The Edge On Your Sharpened Blade
After sharpening, hit your knife on the honing steel a few more times to dial in your edge. Now, test it on a tomato or a piece of paper to ensure you get the edge you're happy with.
This process may take time and practice, but doing it once a year with your knives will ensure you have sharp knives to break down fish of all sizes. If you use a knife often, make sure to sharpen it more frequently. Dull knives cause accidents in kitchens and on boats more than anything else, so keep your AFTCO knife sharp and maintained to last you a lifetime.
AFTCO makes everything you need to care for your fish properly. With everything to get your fish overboard, such as gaffs and quickly dispatching your fish with a fish bat or Ike Jime Spike, to the next level of fish care, AFTCO has you covered.
We also offer all the necessary resources to learn the correct processes for keeping fish fresh on the boat, fish cleaning, and vacuum sealing fish.
