How To Mount A Blade To A Knife Handle?
The importance of health and safety is something that is much maligned by many across the country, thanks to the by-the-book rigidity that it is often enforced with. While in some cases, accusations that it has become over the top can possibly be justified, there are a few tasks that require the utmost care and consideration. One of those tasks is the fitting of a suitable handle to a knife blade.
There are several simple ways to add a handle to a blade, but first, let’s talk about safety. Blades are sharp. Japanese ones are the sharpest. But here is the thing – they’re supposed to be sharp – that’s how they are the safest.
Before starting to work on a blade, you should tape it well. Be careful anyway, the Japanese blades are really sharp and will cut through the tape if you grab them wrong. If you’re working with hot solder or pewter, or power tools, wear safety glasses. The dust from some handle materials can be bad for your lungs. Use good ventilation and/or a dust mask. When you’re working with power tools or sharp stuff, pay attention to what you’re doing. Try to do it in a daily light, where you can see everything clearly. And lastly, don’t try to work when you’re tired or in a hurry.
One of the easiest, ways to make a handle is with antler. Find a suitable piece of antler, drill a hole, and add the blade, and you’re done. You can add a guard, or not, as you choose. It’s not popular within Japanese knives, but very popular among hunting knives.
Mounting an antler is really easy. Pick out the piece of antler and cut it to length. Before you cut it, lay the blade over the piece and see how the tang will fit. By holding the section you can see how it feels in your hand. If your piece of antler includes the crown, you can either place the crown at back of the handle as a pommel, or at the front of the handle as a natural guard. You may have to shorten or narrow the tang to fit in the available space. If you have to narrow the tang, be sure to file or grind parallel to the tang, not across it. Any scratch lines that cross the tang may weaken it, and cause it to break under stress. Drill a hole. Some people prefer to drill a narrow pilot hole, then widen it (but not all the way to the bottom).
You may want to use several size drills so the hole tapers in steps. Widen the hole at the opening with a narrow rasp or chisel to form a slot rather than a round hole. Don’t narrow the tang near the base of the blade, you need the strength there. You only have to do this at the opening where the tang widens. As you enlarge the hole, try the blade for fit until it fits. When you can get it into position, you’re ready for the next step.
Binding handle to the tang
There are several ways to bind the two together. If you don’t care about tradition and go for usability, epoxy works really well. It’s a good idea to clean the tang to remove any oil or grease. If the tang is polished, you can roughen it with sand paper, or add a few shallow grooves, to give the epoxy a better grip. You can dye the epoxy if you wish, or add some of the powder from your drilling to help the epoxy to blend in. If you have taken the time to form a slot just large enough for the blade rather than an oversized hole, it will make a neater appearance.
For a more traditional piece, you can use pitch, or sap from pine or spruce trees. A good approximation of this is ferrule cement. This is an early form of heat glue made for assembling fishing pole ferrules. It contains a kind of tree sap and is available in larger sporting goods stores.
Another traditional method is poured pewter. This can be tricky, and probably isn’t the best choice for a first project. You get one try at the final moment to get it right. Position the handle vertically in a vise or other holder. Wrap foil around the handle to form a collar. Melt the pewter, pour it into the hole, quickly add the blade, and let it cool. It helps to heat the tang as well, so the pewter does not freeze instantly as you are inserting the tang. You need to be careful that the heat does not draw the temper of the blade. Concentrate the heat on the outer half if the tang.
Let the assembly cool completely before removing the foil. It’s best to leave it overnight, or at least for several hours. If you remove the foil before the core is cold the antler may split as it contracts from contact with the cooler air. If you use a little more pewter than is needed to fill the hole, it will form a cap over the end of the handle and hide the hole. You can also cut grooves in a decorative pattern in the handle that will be filled by the pewter. This also helps lock the assembly together. Alternatively you can assemble the knife first, then pour the pewter. Remember to use a lead free pewter if you’re going to prepare food with the knife!
You can also split the difference and set the blade with epoxy, but only use enough epoxy to fill the handle within a quarter inch or so of the top, then finish with pewter. This saves pewter and is very solid.
How to melt the pewter? There are several ways depending on the tools at hand. You can use a torch to melt some off the block into a stainless steel serving spoon or ladle. Then apply the torch to the bottom of the spoon until the pewter is nicely fluid. If you don’t have a torch you can melt it on the kitchen stove with a ladle.
Yet another alternative is to set the blade with epoxy, again leaving some space at the top. Then mix some of the dust from drilling the antler into some of the surplus epoxy and pack it in the top of the hole. This will match the colour of the epoxy to the antler and make the size of the opening less obvious. If done properly, it will look as if the tang was forced into an exactly fitting hole.
If you want to do this in a more period fashion, you can soak the antler in sour buttermilk and vinegar for 6 – 12 weeks, at which time it should be soft enough to force the tang into the antler. After 4- 5 days it will regain its hardness. This is a very ancient method of working antler for all kinds of artefacts. The folks on the Primitive Ways website suggest you can also do his by soaking the antler in rainwater for a month or so.
Types of handles: Bone
Bone makes a very nice handle and is mounted much the same as antler. Quite popular amongst Japanese blacksmiths. Takeshi Saji loves using deer bones in creating his finest knives.
Shall you use one, finish up with a nice polish for a mellow feel and look? If you are polishing on a power buffer, be very careful it doesn’t grab the knife and feed it to you! When working with power grinders or buffers try to stand to one side rather than in line with the rotation. The leg bones from deer work very well with little work.
Types of handles: Wood
Very popular amongst Japanese knives. Wood is a little more work but gives you greater freedom to shape the style you want. Select a block, drill and fit to the blade, but don’t glue it. Then shape and sand the handle, stain and glue it. You can bring the end of the tang through the end of the handle, and peen it down on a nut or washer. You can thread the tang for a recessed nut. An easier alternative is to drill the hole almost, but not quite, through the handle. Shorten the tang to match and bind the two together as with antler.
With wood, you may want to form the hole as a tight slot that just fits the blade. This avoids the need for an end cap or hilt. With a snug fit, you may not even need the pewter or epoxy. Some people taper the tang to a point and makes the hole just a bit short so he’s actually driving the point into the wood of the handle. Of course, if you overdo this you’ll split the handle. The result can be an elegant combination of blade, wood and shape.
The easiest way to form the slot is with a drill press. Using a drill the same size as the thickness of the tang drill two or three long holes in a line that converge at the bottom. Clean out the material between them to form the slot. You can use a combination of narrow chisels and rasps to clean out the space between the holes and open it up for an exact fit. Chain saw files work well for this. You may want to grind a round file flat on two sides and taper the other dimension on one side as well. You may want to taper the tang, but avoid removing material at the base of the blade where strength is needed.
If you are using a drill press, you can make a simple tool to greatly ease the work. Clamp a block of scrap wood to the table of the press. Drill a shallow hole in the wood and fit a stub of nail or drill rod in the hole, leaving a little sticking out. Lower the table, but keep the stub in line with the drill. Now when you are drilling the handle, drill a shallow reference hole in the other end of the handle first. Place this hole over the nail and you will be sure of your hole direction. This makes it much easier to drill converging holes to form a slot. It also is a great help when you are trying to drill through a handle from two ends and get the holes to line up properly. If you are making a handle with a blind hole you can still use this to keep the hole in the line. Just leave the handle a bit long until you drill the hole for the tang, then remove the surplus with the reference hole.
An alternative is to burn the slot. This was often done in early times since long drills were not always available to the maker. Today, it’s easiest if you first drill a hole, then burn the hole into a slot. You can use a piece of steel shaped like the tang, heated to a nice red. Press it in the hole until you are almost where you want the blade to sit, then clean out the char to the final fit. It may take a few passes. Unless you are using a blade that will be heat treated later, do not use the blade you are going to mount. The heat will ruin the temper of the blade. If you are doing a number of knives with the same blade, I suppose you could sacrifice one of the blades as a burning iron, but it seems a waste. It shouldn’t take long to file or grind a piece of mild steel to the shape of the tang.
Hilts & Guards
Adding a metal hilt or guard is a little more work. You may be able to form a guard from the handle material if you have the right piece of antler or shape the wood properly. Many period knives did not have a guard, just as many kitchen knives today do not have guards. People learn not to cut themselves. Also, a large guard or a double guard will limit the ways you can grip the knife, and gets in the way of certain kinds of cuts. It also limits the kind of sheath you can make.
If you use a guard it should fit exactly, with little or no gap between the guard and blade. Because of the polishing, many blades are thinner where the guard sits than they are through the tang. This means you will have to thin the tang to match the blade in order to slide it through the guard. When you do this be sure to draw file or grind it down the length of the tang, not across it. Any scratches across the tang can weaken it and possibly cause failure.
If you are using a pre-made guard try to get one with a slot a bit undersized so you can open it up to an exact fit. You can also make your own from scratch. Brass is an easy metal to work. Drill a line of holes a little smaller than the thickness of the blade. File the holes into a slot for the tang. You want it to fit with no slop or gaps. Getting it to fit without noticeable gap is fussy work, but important. When you have a good fit, shape the guard. If you use power equipment avoid breathing the dust, and wear eye protection! Brass slivers are non-magnetic and really difficult for the hospital personnel to get out of your eye. Remove the filing or grinding marks with successively finer grades of abrasive paper. Be sure to get all the marks out before going to the next finer grit. You should to seal the joint between the blade and guard so moisture cannot get in and rust your tang. Soldering is the usual method. Silver solder is the strongest, but requires a high temperature. If your joint is good and tight, you can probably use soft solder.
Remember to use lead free solder if the knife may be used on food. Clean the parts of all grease and oil. You want to heat the joint without heating the blade to the point where you ruin the temper. It helps to wrap the blade in a wet paper towel. It also helps to use a very small tip on an oxy-acetylene torch, rather than a propane torch, but either will work, especially with soft solder. Flux and assemble the joint. Keep the flux off the surfaces where you don’t want solder. Set the blade vertically in a vise, and apply heat. When hot, apply solder to the tang side of the join. If your joint is tight, capillary action will draw in the solder to just fill the joint, leaving no gaps and no mess on the blade side of the guard. You can also use epoxy or even superglue if your joint is tight enough.
For more tips, we recommend the awesome blog of Ragweed Forge where he shares great tips on knife handles.
And as always, have fun and be safe!