The Joy of Reviving Vintage Knives
I’ve been fortunate enough to turn my knife hobby into not just one, but two side hustles. The first is the obvious one – writing for BLADE Magazine. The second is running a knife-and-tool sharpening service out of my garage, serving folks in my community and metro area with full-service sharpening on most cutting tools found in the home workshop and garage.
I’ve always had a strong interest in sharpening, and have been practicing the skill for about as long as I’ve been into knives in general. While I sharpen many knives and scissors, I also relish the challenge of repairing damaged knife blades. These repairs include, but are not limited to, straightening bent blade tips, fixing severely damaged cutting edges, and regrinding new blade tips from broken ones.
Sure, sharpening is something I still enjoy very much, and to a degree it remains fun work for me. But it’s these minor repairs at customer request that I truly love doing. And you can too, provided you have the proper equipment and the desire to learn.
The Tools of the Trade
Before we get into the thick of blade repair, let’s discuss the essential equipment. I run four Work Sharp Ken Onion Elite sharpening machines – I keep one as a backup or deploy it as needed to augment what I’m already running. I also have a 13″ single-speed belt sander, a Harbor Freight special, that I use for all my sharpening.
The Ken Onion Elite is not just a sharpener, but also a variable-speed miniature belt sander. Especially when you turn the unit around 180 degrees and work off the platen side, you can easily work on plastic, PVC, metal, and wood. This is also how I regrind new blade tips, as well as fix blade damage caused by hitting something solid and chipping the edge.
It’s important to note here that to do blade repairs of any sort successfully, you must have some sort of variable-speed, motorized belt-sander-type machine. The ability to control the speed and dial in the grit is crucial.
Browse our selection of high-quality knives and sharpening tools to get started on your own knife restoration projects.
Bringing an Old Blade Back to Life
Let me walk you through a recent knife restoration project I undertook for a coworker. The demo knife was a vintage carbon steel Case jackknife that had seen a lot of use in a previous life. Both blade tips were broken off, the main blade was extremely worn down, and there were some dings in the cutting edge as well.
The owner wanted me to rehab the blades by regrinding new tips and sharpening them. I’ll take you through the step-by-step process of what I did and how it was done.
Warning: Proceed with Caution
Before we dive in, a word of caution: When working with power tools like belt sanders, please exercise the utmost caution. Should you attempt such a task, neither I nor BLADE is liable for any injuries that might occur as a result.
Whenever executing blade repairs, remember to not let the blade heat up, or you can ruin the steel’s heat treat. Always keep a jar filled with water within arm’s reach of your machine and dunk the blade into the water every few seconds to keep it cool. This will ensure that you don’t overheat the steel.
If working on a larger blade, such as a machete, I recommend using a spray bottle filled with water. The blade is simply too long to dunk into a jar, so spraying it down every so often will help.
It’s also a good idea to have a pair of cut-resistant gloves on hand and always wear them when handling the blade. The gloves usually have a textured coating on the gripping surfaces for the fingers and palms, which will help you hold the blade securely as well as keep your hands and fingers safe from accidental cuts.
Regrinding the Blade Tips
I started the blade repair process by using my 13″ belt sander with an 80-grit Norton Blaze SG belt, which is specifically engineered for knifemaking and removing steel. This coarse belt allows me to hog off material and roughly shape the new blade tips.
I began by visualizing where the new tips would lie, starting at the uppermost point of the broken-off tips, usually on the blade spine side. I then started grinding at that point and removed material until a new tip was created. As I ground it down, I also paid attention to the visual flow of the new tip and how it transitioned to the rest of the blade spine. I may have had to round off the harsh angle to blend it back into the spine – a lot of this was done by eye, making everything blend just right.
The goal was to make the new blade tips look as though nothing had happened. After roughing out the new tips with the 13″ belt sander, I began to dial in the final shape using the Ken Onion Elite. The slower belt speed and less aggressive grit allowed me to finesse the new tips, keeping a close eye on the evenness of the ground-down portion and making it parallel with the rest of the untouched blade spine.
Once the new tips were shaped to my satisfaction, I focused on the finished appearance by holding the knife almost vertically and sanding only on the ground portion. This helped blend it in visually and removed the coarse-grit scratches with the 80-grit belt on the 13″ sander.
The final step was to chamfer the ground portion and remove the crisp corners made by all the sanding. I held the blade at an angle and lightly touched the blade spine to the belt to cut the crisp corner down. The key was to use a light touch and stop only when the corners were smooth to the touch, and I couldn’t detect any crisp edges. The result was a new blade tip that was highly functional but didn’t look factory-made, though it would be awfully close.
Straightening the Cutting Edge
The main blade of the demo knife was worn away unevenly due to years of manual sharpening, so I straightened that out as well. Like the shaping of the new tips, I did the bulk of the straightening of the cutting edge on my 13″ belt sander. I used a light touch on the belt, as it’s easier to grind cautiously and keep an eye on the straightness of the new cutting edge.
I ground a bit, then dunked the blade in water to keep it cool. Once I attained an even edge, it was time to grind the new edge. Straightening out the edge would cause a wide flat spot, so I had to grind that spot away evenly on both sides. I worked diligently and carefully, not forgetting to dunk the blade in water.
With the smaller of the two blades, I repeated the same steps to even out the edge, as there were some imperfections I wanted to remove. As a result, I ended up starting a new edge on the small blade as well.
Sculpting the Final Edge
Once I had the starter edges ground, I progressed to the Work Sharp Ken Onion Elite machines to carefully sculpt the new final edges. This is the step where you really bring the blades to life. The carbon steel blades made the process easy, as they sharpen up quicker than stainless steel.
After the final sharpening of both blades, the result was a vintage pocketknife with a new lease on life, sporting new tips and fresh cutting edges.
The Satisfaction of Knife Restoration
Sharpening – transforming a cutting tool from dull to razor-sharp in a few minutes – is very therapeutic. Toss in creating new blade tips on top of that, and the combination is undeniably satisfying.
If you carefully follow the steps I’ve outlined, you too can renew any knife blade with a broken tip. And it doesn’t have to be a pocketknife – I’ve ground new tips on tactical folders and karambits as well, using the same process.
In fact, larger knives are probably easier, as there’s more to hold onto while working on them. Just be sure to exercise the same caution, keep the blade cool, and wear those cut-resistant gloves.
So if you have the equipment and the desire to revive and rehab knife blades, give it a try! It’s a highly rewarding project that can breathe new life into your old, worn-out cutting tools. Who knows, you might even find some other uses for that 13″ belt sander beyond just blade repair.
Discover our selection of high-quality knives and sharpening tools to get started on your own knife restoration journey.
The Thrill of Using Restored Tools
I love using old tools, previously owned by makers whose skill level I’ll likely never reach. There’s something incredibly inspiring about imagining their lives, their hands, and the pieces they built with these very tools.
When tools are properly restored, they are often just as good, if not better, than many products made today. And the history that accompanies them is so captivating. Using antique tools to build furniture that breaks the Ikea mold – furniture that will last not only my whole life but will likely outlive my grandchildren – is an amazing experience.
Antique metal tools can often be acquired and restored inexpensively, but depending on the condition, the process can take time and patience. I’ve tried various methods, such as baking soda and vinegar, oxalic acid, or electrolysis, but the one I use most is the citric acid process.
I try to use as many natural or organic products as possible, leaving the heavy chemicals outside the shop. After all, you never know who might wander in – kitties, bunnies, chickens, and ducks are frequent guests in my workspace.
The Art of Restoration
When I first started restoring old tools, I got most of my basic set in one big lot on eBay. I cleaned, sharpened, and rehandled around 150 blades of various kinds within a few weeks. It was a huge task, but it ended up being totally worth it, as I gained a ton of practice not only in restoration but also in grinding and sharpening.
I was taught to do both freehand, which saved me a lot of time in the long run. If you don’t already do this and have some items you wouldn’t mind grinding down a bit, I would highly recommend giving freehand grinding and sharpening a shot.
The process of restoring old tools involves several steps, from the initial cleaning with dish soap and water to the final oiling and waxing. One of the key steps is the citric acid or vinegar soak, which helps remove stubborn rust. It’s important to be cautious during this stage, as the acid can start to eat away at the metal if left too long.
After the acid soak, I use a series of nylon brushes, old toothbrushes, Q-tips, and paper towels to finish the cleanup on the metal. I’m very careful here to remove the dirt, grime, and rust, but nothing more. Especially on hand planes, you want to be very careful to keep as much of the Japanning or black paint on the interior as possible.
Once the metal is clean, I generously oil the tool, coat it with paste wax or Boeshield (my favorite rust prevention product), and reassemble. For wooden components that aren’t too damaged, I like to leave them as they are. If they need to be replaced, I follow instructions for making a new handle.
The Joys of Handiwork
Using old tools in the workshop is an amazing experience. When they are properly restored, they are often just as good, if not better, than many products made today. And the history that accompanies them is so inspiring.
I imagine the lives, the hands, and the pieces they built. It’s a really incredible feeling using antique tools to build furniture that breaks the Ikea mold and furniture that will last not only my whole life but will likely outlive my grandchildren as well.
Restoring old tools is a labor of love, but the satisfaction of bringing them back to life is unparalleled. Whether it’s a pocketknife, a tactical folder, or a hand plane, the process of carefully repairing and sharpening these tools is both therapeutic and deeply rewarding.
So if you have a passion for knives, tools, or just the joys of handiwork, I encourage you to dive into the world of tool restoration. With the right equipment and a little bit of patience, you can breathe new life into your old, worn-out cutting tools and create something truly special.
Explore our collection of high-quality knives and sharpening tools to get started on your own knife restoration journey.
