How many times have you heard that dull knives are more dangerous than sharp ones? If you use pocket knives or multi-tool knives on a regular basis, then you already know how true this is. A knife is one of the main tools in a multi-tool, and it does get blunt over time. If you want your multi-tool to always remain as functional as ever, then the first thing you have to do is get the blunt and worn-out knife sharp.
You can sharpen the knife in a multi-tool yourself by various means. The most common methods include using a pocket knife sharpener, a sharpening stone or whetstone, or a ceramic sharpening rod.
All the different ways by which a knife can be sharpened usually apply to multi-tool knives as well. Good multi-tools last a lifetime, and depending on your usage pattern, the knife in the multi-tool will probably need sharpening several times. But multi-tool knives are relatively small, much smaller than normal kitchen knives. Hence, small sharpening tools that you can carry along with you if required are a much better solution for keeping the knife usable and functional over the long run.
Pocket Knife Sharpner
The easiest way to sharpen a multi-tool knife is to use a custom knife sharpener. These types of sharpeners are specifically built for portability. A ton of knife sharpeners is available in the market. The one I have used that works quite well on multi-tool knives is the Victorinox Pocket Knife Sharpener.
I think Victorinox built this for their Swiss Army Knives. Victorinox Swiss Army Knives are known to be made of soft steel, and hence easier to sharpen.
But I was surprised to find that this sharpener works well with other knives too. I have used it on my pocket knives and even Leatherman multi-tools as well with excellent results.
The design of the sharpener is like that of a pen with a pocket clip. On one side, it has a v-groove sharpener, and on the other side, a long ceramic rod. The good thing about the v-groove is that it takes the guesswork out of the sharpening process. You just have to pull the sharp edge of the knife through the v-groove for a few times. Just maintain light but consistent pressure while doing so, and your knife will get a fine sharp edge.
In case your knife is badly worn out and have uneven dents, you can use the sharpening rod at the other end to smoothen them. Then, use the v-groove to give it a sharp edge.
The sharpening rod also has grooves that can be used to sharpen fishing hooks.
I have sharpened all my Swiss Army Knives at least once, and some Leatherman multi-tool knives, and also kitchen knives with this knife sharpener. I am not an expert at knife sharpening, and hence for me, this was the easiest method. Considering how easy it is to use, with all the different sharpening options this tiny tool has coupled with Victorinox quality, this can very well be the only tool you need to sharpen your multi-tool knife.
Sharpening Stone or Whetstone
Stones have been used to sharpen knives for ages. It is the old-school way that always works for all types of knives and sharp metal objects. The sharpening stones or whetstones you get in the market are just custom made for this. These are available in different sizes, and a small one that you can carry comfortably will just be the right choice for your multi-tool knives. Apart from the sharpening stone, the only thing you will need is a lubricant, like mineral oil. However, water will also do just fine.
Note that sharpening a knife on a sharpening stone requires a bit of practice. Multi-tool damage due to home sharpening is not usually covered in the warranty. So if you don’t want to risk damaging your favorite multi-tool knife, you can practice a bit with old throwaway knives first.
The trick is to maintain a constant angle while rubbing the knife-edge on the sharpening stone. Try to maintain a consistent grind from the tip of the knife to its base. You should sharpen both sides of the knife blade in a similar manner. Knife blades edges usually have an angle of 15 to 30 degrees. Without some practice, you may find it difficult to maintain that angle. Also, the heat generated from the friction can bother you a bit. Too much heat can even bend or change the shape of the knife. Water or any other lubricant can help reduce the heat, as well as clear debris.
If you haven’t tried this before, do watch some videos on YouTube to get a better idea. Here is an excellent one that explains the process very clearly.
You may get quite different results depending on how expert you are at sharpening with a Whetstone. However, once you get a hang of it, you can apply the process on a wide variety of knives of all sizes as well as other sharp objects.
What About Serrated Knives?
Serrated knives work better than plain edge knives in certain situations, but can you sharpen them like plain edge knives? Things do get a bit complicated in case of a serrated knife.
Serrated knives usually hold an edge longer than plain edge knives, but they do get dull over time. V-shaped sharpeners or sharpening stones do not work in this case.
You need a sharpening tool that can accommodate the serrated edges or the grooves of the serrations. Each groove of the serration has to be sharpened individually. Also, serrated knives are sharpened only on the edge side, and not on the flat side.
The best tool for the job is a ceramic sharpening rod, also referred to as honing steel or honing rod. Choose a ceramic rod whose diameter matches the groove of the serrations. You need to place the rod in each of the grooves of the serration individually and rub it up and down. The process is a bit complicated and time-consuming. The ceramic rod of the Victorinox Pocket Knife Sharpener can also do the job.
Here is an elaborate description of how to sharpen a serrated knife:
To sharpen a serrated knife edge, consider doing so with a round sharpener or a similar style stone. Lay the diamond shaft in the serration and file up and down in each serration along the entire blade. When sharpening of a serrated blade is sufficient, a burr can be felt on the flat, or reverse side of the knife blade (you can feel the burr with your fingernail.) This burr should be removed by rubbing that side of the knife with the Diamond Knife Sharpener with a circular motion. If no burr appears, then the angle was too small and the work on the grooves must be repeated using a larger angle.
Courtesy ‘Gerber Multitools’
Diamond Coated File in a Multi-tool
Ok, this is a bonus tip but works well when you do not have the above-mentioned tools. Some multi-tools do have a diamond-coated file. I have a Leatherman Wave, and one side of the file in it is diamond coated. At times of need, you can definitely use this edge similar to a ceramic sharpening rod, or a sharpening stone.
Will it work as good as a sharpening rod or stone? Probably not, but it will at least make the knife usable again. Only problem? You cannot use it on the knife of the same multi-tool for obvious reasons. So this technique will only be useful if you are carrying two multi-tools. In bigger multi-tools like the Leatherman Surge, the file is replaceable, so it is possible to just pop it out and use it to sharpen the knife.
However, if you do use the diamond file, remember that it is a bit coarse and hence will be aggressively removing a lot of steel. Just use it very sparingly and you will do fine.
As you can see, sharpening a multi-tool knife is not hard at all. If you have the right tool for the job, you can sharpen all your multi-tool knives yourself. If you use the knife in your multi-tool extensively, just get one of these tools and you can keep the knife razor-sharp throughout the life of the multi-tool.