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Chip Fix: Seven Approaches to Repairing a Damaged Knife Edge
It is a sinking feeling when you take a look at the cutting edge of your knife, and see a chip in it. But it happens. Sometimes completely regrinding the bevel is the best solution, sometimes not. Below are some options to consider, depending on the nature, size and location of the chip, how the blade is used, and what your sharpening set-up is.
1) Live with it. This is often a good solution for small chips. It will make a weird little ridge in the leather (or other material), and you will have to go back over it with a different part of the knife, like removing the ridge between multiple passes of a double edge razor blade paring machine. As you resharpen the blade it will get smaller each time.
2) For large chips, alter the cutting angle around the chip so the blade can still function. The example above shows a huge chip, and fixing it by regrinding the bevel would have removed most of the knife. The previous owner cleverly fixed it by putting an edge on the large chip. This blade still works quite well for hacking small branches. In fact, I kind of like having the notched higher bevel area. Of course, this depends on what type and size of blade you have and how you use it.
3) Regrind to the original bevel using the coarsest diamond stone you can find, at least a 220 US grit. Even though I have belt grinders, for a narrow chisel like this one, it is easier to control working by hand on a diamond stone. It really doesn’t take that long. And you can skip your HIIT tomorrow.
4) Regrind to the original using a belt sander, belt grinder, Tormek, or a stone grinder. If the blade is wide or thick, and the damage severe, a complete regrind might be the best option. Obviously, it is quicker to have a machine do the work, rather than your arms. I highly recommend the Kalamazoo 1 x 42 belt sander if you are in the market for a new one. I’ve had one for over 20 years, and sometimes during workshops it has run almost continuously for a couple of days.
5) To fix a chipped corner, if the width of the blade is not of that much importance to you, it is often easier to reduce the it rather than regrind the bevel, like on the chisel above. This can ruin a rare or important tool, though. Often the entire width does not need to be reground, as the image above shows, but it can be rounded towards the tip. This can be done by hand on a diamond stone or on a machine grinder. Sometimes only a small amount of the blade on the bevel needs to be ground, sometimes the entire length. In this case, it was an inexpensive Buck chisel that I use for crude chopping, and has little value otherwise.
6) If the tip or corner is chipped (which is very common) it can be easier to round it. Some prefer to have rounded tips on leather paring knives and other knives anyway. Think carefully if you want to keep the original bevel angle, or raise it slightly as in the above example. The above chip could also be fixed by reducing the width of the knife on the left side of the image.