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Bob Engnath on Knife Handles

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AFTER THE GUARD OR BOLSTERS


The grip is drilled lengthwise with a 1/4" bit, pushing it up and down to make the hole at the guard into an oval shape.

Final fitting, once the tang hole has been opened large enough for the grip to seat against the guard, is completed with filing or sanding to cut the front end of the grip square. The joint between grip and guard should be precise and without gaps. Fit the butt in the same way. Check by running it on as tight as possible with the bare hands and looking for gaps.

When everything fits, butter up the tang and fill the tang hole with epoxy, following the epoxy package instructions and assemble again, filling every crevice with epoxy. Remove the excess and allow to harden. Spacers may be added without changing the fit.

If a butt cap is not desirable, try this:

Countersink the tang hole about 3/8" deep and large enough to accept a 1/4"-20 nut. Bury the nut in the epoxy when assembling, using a needle nose pliers to tighten it and then use either sawdust mixed with epoxy or a plug to fill the hole. Be sure to shorten the threaded rod on the tang so it won't show.






BLIND TANG

This is usually used for the stag crowns.

The tang should be notched to anchor it solidly. The small vent hole allows epoxy to be forced all the way to the bottom of the blind tang hole without air bubbles. It should be taped shut after the parts are assembled and the epoxy is ready to harden.




RABBET TANG




Your grip is made in halves, each half chiseled, routed or milled out to just a hair over half the tangs thickness. File or sand each part to fit the guard, drill the pin or bolt holes and assemble for a trail fit. Assemble with epoxy if everything fits.




Micarta is preferred for this type since it provides true, flat surfaces for the center joint.








THE COMBAT HANDLE

You may use virtually any blade with slab handles and built in guard to make the combat style handle, even those that are made to take bolsters. All you need to do is get a slightly larger set of handle slabs so that the guard extensions may be covered with the same material, and piece, as the handle. If you're working on one of ours, please mention which model when ordering the slabs.

The combat grip is simply a slab or rabbit tanged knife where the guard is formed from the same piece of material as the rest of the handle. The rabbit tang style makes for a surprisingly lightweight knife.





You'll see in our sketch, that the product is simple in design, clean in appearance and relatively easy to make. There are no pins, bolsters or other fancy gadgets to clutter things up, and the assembly is about as strong as you can get.











SLAB HANDLES

These are the most popular style grip for the modern, handmade knife. There are many more variations than I have shown here.




HALF TANGS

The half tang is a machinists delight. It provides a maximum of strength with the light weight of a stick tanged model. If prepared properly, fitting is perfect, right off the machines with no hand work.

There has to be a catch, right? Well, there is. You need access to a horizontal mill with the right cutter for a short time.

The handles are made from chunks rather than slabs, with a slot cut in them almost to the back of the material. This slot is parallel to the top edge except at the end where it curves up in the diameter of the cutter.

The tang only has to be perfectly fit at that one spot, where the upward curve of the slot comes out of the back of the knife. You can go even farther with this, taking the slot right out the back of the handle if you'd like the tang to be a bit longer.

Drilling these looks like it could be a problem, but there's an easy way around. Put the blade flat in your drill press vise with the tang

completely accessible. Put the right drill in the chuck. Move the vise around until you can pull the drill down through the tang hole. Anchor the vise. This is a lot easier if you have one of the inexpensive milling vises.

Now, slip the handle on and squeeze it with vise grips or a clamp to hold it firm while you drill right through it and the tang hole that you should be indexed on. Perfect fit. Remove the handle and re-index the vise to the second hole. Put the handle back on and pin it through the first hole. Drill the second hole like you did the first.

You can go even farther with this, taking the slot right out the back of the handle if you'd like the tang to be a bit longer.

If you are after a dull finish, use a non-reflective grip material in either linen or canvas micarta. One of these can be shaped and finished in about ten minutes flat, assuming you have a grinder that can use a small wheel attachment and do slack belt work.




HANDLE BOLTS AND MATERIALS

Fit your grip material to the tang very carefully. Final shaping should be left until after gluing. Test the fit all parts before mixing the epoxy. Don't mix more epoxy than you need for one knife. Mix epoxy on something that you can throw out when you're done. Notch the underside of bolt heads to anchor them in your epoxy. Bolts and pins should slide into the handle easily.

We recommend using only a modest amount of epoxy, well mixed, and moderate clamping pressure. Heavy clamping will squeeze out so much epoxy that it cannot give a decent bond. Try putting a tiny bit of typing paper between the tang and the slab handle, positioned beneath the clamping points. It'll act like a small shim and help prevent squeezing out all of the epoxy.

When the epoxy sets, saw the bolts and heads off flush with the grip material and shape the bolt along with the rest of the grip. When test fitting the handle, be sure to countersink the bolt heads in deep enough to allow for the final contour shaping of the grip. You don't want to cut right down through the whole handle slab, but, on the other hand, you need to have about 1/8 inch of handle material under the head of the bolt. It's enough to make a guy start using nothing but pins!

Bolt heads are normally long enough to stick out of a grip slab far enough so that they may be turned tight with a pliers. If they're not, perhaps your proportions are off a bit.

If you're worried about the bolt heads eventually working themselves loose, jus cut a couple of tiny notches into the bottom surface, where they bottom out. Epoxy will fill them and anchor the bolt head so securely that even burning the epoxy won't let them loosen. Should you absolutely have to remove a part which has been glued, lay the knife on a slab of dry ice for half an hour. the bond will become brittle enough to release easily when you give it a sharp wrap.

Invisible handle bolts are a handy trick. George Nixon suggested this one. He uses a short length of threaded rod through the tang, and about half way into the inside of the handle with blind holes. The blind holes should be a little larger diameter than the rod so the epoxy has room to hold better. When it's all fit, just epoxy the slab on, and the short stub of threaded rod will hold as well as most straight pins do. If you're working on a soft blade, thread the tang to fit the stub of threaded rod sticking through it, and it'll be even stronger. There's a sketch a bit farther on.




Wood grips may be power sanded or filed to the right contour with a coarse "bastard" file, using a half round shape for the inside or concave curves. Check our safety section for warnings about wood dust. Most woods will eventually turn gray if handled with sweaty hands. Exotic varieties eventually turn dull as they oxidize. Use wood bleach to stop that tendency.

Stabilized wood comes in many varieties. The oldest is done with something called P.E.G., designed to keep green woods from checking, which is not good for knife handles. Next is a plastic resin injection type of stabilization that works on most woods that don't have a lot of natural oil. It toughens burl or root wood to the point where it becomes a decent handle, and makes it dimensional stable but does not completely seal the pores. An offshoot of this type is a resin injected variety that has been colored by a patented radiation process and looks great. Finally, a woodworking magazine has written about a fourth type that is supposed to stop shrinkage and stabilize color by using entirely natural materials. This one is not seen in the knife makers' market yet. Go with the second type or its' colored version. Some of these stabilizing processes use M E K peroxide, which is not a nice thing to have around the house. It is so unstable (in the raw state) that it may literally explode at room temperature.

Micarta is very stubborn and just about has to be power sanded, but will file to shape if your patience holds out. Ivory or Ebony, paper type micarta seems to file easiest. The current formulation of "ivory" or "white" micarta is not as good as what was available a few years ago. If you find some really silky looking micarta at the salvage yard, pass. It's made with fiberglass and will take the teeth right off most files. Paper micarta may be scrimshawed. The newer stuff isn't as dense as the original type, and will often end up with a slightly porous finish that catches buffing compound.

When finishing paper base micarta, get to your last hand rubbing step, and then coat the handle with super glue. Use one of those photographers lint free wipers to apply it. Put on a thin layer, let it soak in and then wipe off the excess. Sand again, but just enough to break off the excess glue. Go ahead and polish. The super glue should have filled most of those little pores that are such a problem.

Stag should be hand filed to final shape. Power tools heat it quickly, producing a hard, brittle layer, turns it brown and make it really smell awful! Stag is considered a premium material for handles and is getting rather expensive. If you have the crown section of an antler, and there's an ugly knot where they cut off the lower tine, that area may be re-textured by grinding with a Dremel machine and colored with ordinary shoe dye. If you want to color stag deeply, or right to the core, use aniline dyes. Mixed, according to instructions, they will penetrate a fraction of an inch, or right to the center, depending on how long you soak the stag. Thanks to Jim Hrisoulas.

Stag may also be colored with alcohol based shoe dyes. If you plan to scrimshaw stag, use the same super glue coating as with micarta. Stag is easy to overwork, breaking up into knots of fiber, if scrimshaw work is overdone.

Stag can be stained dark brown with potassium permanganate crystals dissolved in water to make a saturated solution. That means you keep adding the chemical until it simply won't dissolve any more. This stuff will stain anything else it touches, especially fingers, so be careful.

There has been a bit of molded plastic, fake stag used in some commercial knives. Don't bother with it.

If your stag is hard to hold on to while grinding the piece to fit a flat tang, try adding a small handle of wood by attaching it with super glue. Bob Jones tells us that this is really handy, and may be removed with a sharp knock later.

Amber is a scarcer material, but easy to work. Just treat it like plastic. Don't get it too hot or put a lot of stress on it. Amber is not very hard. Pressed amber, reconstituted from resin and the scrap of real amber, has flowing lines within the bead that are virtually never seen in the real stuff. The chief over at The Sword and the Stone tells me that baking amber at around 200 degrees F for awhile will turn it into that really rare, red variety. Be sure to let it cool v e r y s l o w l y ! A great deal of the amber seen in neatly shaped beads with ribbons of whitish coloring inside, are simply a high quality plastic and not even a relative of real amber.

Buffalo horn, and even ordinary cow horn is seen on a lot of fancy art-type knives. It is very soft and easy to scratch, but shapes quickly on the sander and is easy to polish. It will certainly warp if you get it hot, and can show stress cracks at the end cuts or drilled holes. Dust is hazardous. Some cracks may be hidden with the penetrating type of super glue. May be scrimshawed easily.

Turtle shell comes in quite a few varieties, with some of them on the endangered species list. Be sure what you're using before putting it on an expensive piece of work. Shell is tough, but has many of the hazards associated with buffalo horn, including the dust hazard. Accepts scrimshaw.

Pearl is a tough material, but not impossible to work with hand tools. It is very brittle and the dust is extremely dangerous to breath. Expensive, and hard to find in larger sizes. Pearl may be engraved or scrimshawed if you're somewhat masochistic.

Ivory is a lovely material for the high quality knife grip, often used in old fighting knives because it didn't get slippery when wet. Ivory should be well aged, years at least. If heated, it is likely to warp, and if not fully cured, it will shrink. Ivory expands and contracts with humidity changes. The dust is not good to breath. There are some ethical questions with using ivory from endangered species. Any elephant ivory in the U.S. now, was legally imported before the species became endangered. Fossil ivories, like walrus and mammoth or mastodon, have no such problem. Most ivories may be stabilized. Ivory is the premier material for scrimshaw, and it may be engraved with specially ground tools. Some states restrict the sale of ivory which is legal by the Federal law. (Easter egg dye works on ivory, but you have to dry cool it really fast so there is no expansion from adsorbing moisture.

Corean is an artificial marble for counter top use. Chunks of it make excellent handles, and the material is not hard to shape or polish. Works about like a very tough plastic, and is likely to dull tools quickly because of the silica content. Perhaps a bit heavy for a working knife.

Stone has always been a highly desirable grip material, although hard to shape without a whole lot of lapidary machinery. Brittle and heavy, but dimensional stable. Natural stone is generally rather expensive. Several types of re-constituted stone are now available. These come in neat slabs or chunks, with less waste and are a lot easier to work with, although they're not exactly like shaping plastic. Stabilized stone is generally made from the original mineral which has been ground and re-formed into a usable mass with the use of plastic binders. The quality varies, ranging from half plastic to as little as fourteen per-cent. If you have an option, go with the type having the higher content of mineral.

Silver and other precious metals have always been used on knife handles and fittings. If you have the ability to wax cast, or a friend who will do it for you, many intricate and good looking parts of a grip may be created by simply making a wax master of the part, right on the blade. The wax original is the master, so shrinkage is less than one half of one per-cent. For built up parts, silver is many times easier to shape than brass or nickel alloys, and it solders effortlessly. Using precious metals is not as difficult as one might suspect and adds a great deal of value to a knife. Easily engraved.

If you are making a segmented handle for a stick tang knife, the parts will be a lot easier to work if they're all about the same size when they go on the handle. You can stack them, and stick them together with double sided carpet tape. Then go ahead and use the sander to rough the whole unit into the approximate shape you want. Saves a lot of time later. If you have access to a surface grinder, you can use the carpet tape to hold down irregular shapes of materials like amber or stag, to grind a surface flat, then flip and tape again to get the parts to the same thickness. Thanks to D'Holder for that one.

After filing or power sanding grip and guard, continue with finer sanding, right on up to 400 or finer. A rub with 600 will shine up the guard if you let the paper get half clogged up.

Always use a sanding block when working across the junction of the handle material and guard or handle bolts so you don't take the wood or micarta down lower than the metal.

Never buff a slab handled grip with the knife held vertical, so the buff runs along the length of the tang. It'll take off handle material, but leave the tang standing above it.

Wood grips should be sealed to prevent sweat staining. We recommend Watch Danish Oil or a tung type oil. Any oil finish will eventually oxidize and darken the wood. Using a plastic type sealer will slow or prevent the darkening or oxidizing of the wood surface. Wood bleaches often reduce the oxidation and eliminate darkening on the real problem woods like cocobolo. More on wood finishing later.

Using natural materials, even some types of wood, raises the possibility that one might accidentally transgress against the endangered species act, a formidable and oft mis-used law. In California, I may not sell a knife with California deer antler on it, but sambar (India) stag is fine. That's a California law, but every bit as much of a problem as the national ones. There are several suggestions. One, none of this stuff has serial numbers, so a single receipt for a legal type of material could possibly cover a lot of ground. One - A, enforcement people rarely have the slightest idea of what they're looking at. Second, never argue with the officer. He has the badge, gun and Motorola. If you bruise him, there will always be charges that the oft used receipt will not get you out of.




GLUING ON SLAB GRIPS

Make sure the surfaces to be joined are true and match each other well enough so the handle bolts will provide all necessary pressure for gluing.

For a knife without a guard or bolsters, use a clamp or vise grip pliers to hold one half of the handle in place on the tang. Drill your holes through from the tang side of the set-up, with the tang making its' own pattern.

Separate the tang and first handle half. Use the drilled half of the handle as a pattern to drill the second half. Clamp the two parts together, making absolutely sure that the ends towards the blade are lined up perfectly. Finish the leading or front edges of each slab before gluing. Utility knives are a lot easier to clean if the leading edge of a plain, slab handle has been cut at an angle.

If your knife has bolsters or guard, drill each of the handle halves right on the tang.

Countersinking for the bolt heads may be done with an ordinary drill, centering it on the pilot hole and enlarging the hole part way through the handle half. The larger drill will want to grab, so clamp the handle down to the drill press table keep it from climbing the drill and countersinking all the way through the handle. ( That's an "oh shit" as we call it in the trade.)

This may sound silly, but be absolutely sure you are drilling the countersink from the right side of the handle. I sell an awful lot of second handles to fellows who forget to check this simple item.





Never clamp a set of scale grips with extreme pressure to make them fit. Using force to make the material conform will result in the joint being severely stressed, sometimes to the point of literally popping loose when clamping is removed or at a more embarrassing time, like after you deliver it. Excessive force also squeezes most or all of the epoxy right out, weakening the bond severely. If you must clamp heavily, put tiny pieces of typing paper between tang and handle to act as spacers which will insure a good layer of epoxy remaining.

It is a lot easier to spend a few extra minutes to make the handle conform to the tang, than it is to repair the handle if it pops off. It is very difficult to grind a tang absolutely true flat. When it appears there is a slight irregularity on the tang of the knife that holds the grip slabs from fitting properly, you have to be versatile. Try scraping the inner, joining surface of the handle with a knife blade, sideways, to remove enough material and allow the slab to mate properly. More on this a little farther on.

No epoxy can do its job on perfectly smooth surfaces that have picked up bench or finger grease. Always rough up the gluing surfaces and give them a thorough cleaning before buttering on the epoxy.

When using handle bolts which are smaller in diameter than the handle holes drilled for bolts, be sure the epoxy doesn't allow the slab to slide around on the tang when you clamp things down. Epoxy will act as a lubricant between the tang and the handle when you put on some clamping pressure. This isn't too much of a problem unless you're fitting the slabs tight up to either bolsters or a guard.

To keep the slabs from sliding around, try drilling the holes in the slab off - center in the tang holes. Drill the front hole as far forward as possible, and the back hole as far to the rear as you can. This may not look too wonderful on the inside, but it'll reduce movement until the epoxy hardens, and is invisible from the outside. If your bolts fit the tang holes tightly, don't worry about offsetting them. Some bolts are a lot smaller than the tang holes. If you think the handles might slide under gluing pressure, put a short, blind pin through one of the pin holes, drilling just a short distance into the inside of the handle so it won't be visible but still does the job.

Adding liners or spacers to your handle can be a real pain in the tush. Epoxy will act just like a lubricating film when parts are clamped, so things will move, even if they appear to be in there correctly.

Try putting the liners and spacers on the handle slabs with epoxy before assembling the slabs onto the knife. Substitute a flat slab of steel for the knife tang, covered with a single layer of wax paper to keep the epoxy from sticking, and then add the sandwich of liners or spacers, buttered up with epoxy, and then the handle slab. Clamp the whole works gently and let the epoxy set. This also is handy with spacers on a stick tang handle. Once the epoxy has hardened, you have only one piece to put on the tapered tang, not two or three. You will be able to treat it as a solid mass and not a collection of parts as you shape and fit the grip. This trick is especially good for the little bits of spacer that you want to put between the guard and handle slab, at right angles to the length of the handle. Those little bits almost always slip, leaving irritating gaps that reduce the quality of your knife and let the kids hear some of those words that they shouldn't.

Slab handle blades may have the strength of an epoxy bond increased a lot by simply having some extra holes in the tang. A glue bond may also be made stronger by drilling a few very shallow holes into the inner surface of the slab.

If you are attaching a pair of slab handles on a blade which has no guard or bolsters, be sure to rub a coating of candle or bees wax on the (finished) front edge of each slab. This will keep epoxy or other glue from sticking to that surface, making it a lot easier to clean up later. Thanks Jim Mattis.

If the grips don't exactly lay flat on the tang, don't be too shocked. I haven't seen a perfectly flat tang or grip yet, much less ground one myself.

Your choices are to fiddle with one or the other until the fit is acceptable. Lets fiddle with the grip. It isn't made of hardened steel and will be easier to manipulate.

Use a scraper on the inner surface of the grip, shaving off microscopic bits until things fit. You can make a scraper very easily by grinding a slightly less than 90 degree angle on the end of a steel bar and honing it to a reasonable degree of sharpness. See the sketch. Use the scraper with a drawing motion. It will work far more precisely than sanding or trying to grind material off.




EPOXY NAILS?

Eric Himel came up with this concept, and it seems to work for fine collectable knives.

Rather than clutter up the handle with bolts or pins, Eric uses a rivet shaped mass of epoxy hidden under the handle surface, holding things together.

He gets the handle fairly well fitted, then drills a hole half way through the handle, but from the inside. The hole is a fraction larger than the bolt hole and should be centered on them.




The only catch is the tendency for the scales to slide when clamped on a tapered tang with epoxy to lubricate the joints. If you slip in a concealed pin, using either one of the bolt or pin holes, the scales won't slide.

SPACERS, SUBSTITUTES

Stacked spacers for stick tang knives do not have to be made from the standard "Vulcanized fiber" material. You may salvage plastic from any container that you feel is the right color, and put it in like regular spacer material. The plastic should be roughed up a bit on the gluing surfaces, and clean. Most of these plastics do not glue very well, so we do not recommend them for the full length spacers on a slab handle unless you punch the hidden part with a lot of holes for the epoxy.

A major advantage to using plastic containers is that the material will not adsorb moisture like the vulcanized fiber does, meaning that it won't get stained or mess up the joint when it gets wet. Old gunsmiths trick.

Spacers on the old Scagel knives were made from bowling ball material. From Frank Gamble.




FINISHING WOOD GRIPS

Most beginners figure that a coat of good ole' linseed oil will make a decent finish for the wooden handled knife. Maybe, if it's never going to go out in the field, and you don't mind it gradually darkening until most of the woods' character and color has oxidized to a plain brown. If you don't think that wood oxidizes and changes color, just split a block of cocobolo that has been sitting around the shop for a year or two. Linseed oil oxidizes as part of the curing process, and does the same to the wood. A simple oil finish is also rather easily damaged by moisture, read sweat, on the working knife.

If you want to keep the relative brightness of a wood, and avoid a lot of the oxidation effect, the wood should be bleached with commercial wood bleach,(Jasco A-B type). This will lighten the colors so that when you darken them with a finish, you get back to about where you started. Some woods, like wenge, may be bleached into startling contrast, delivering a color that is more interesting than the original.

The most exotic finish for fine hardwood that I have found is the one used by Scott Slobodian, on his incredible Japanese swords and daggers. He uses exotic and spalted billets of wood that simply seem to glow, beneath the thick, transparent finish.

Scott uses built-up layers of plain old super glue, as many as forty. He applies the glue with lint free, photographers wipers, in smooth, even layers. Each successive layer is left untouched. If roughness appears, it is polished out when the build up has been completed. Any sanding or work done on a layer would be visible as additional layers built up over it.

Super glue is a form of acrylic plastic, easy to polish.

The only draw back found with this finish, is that it actually adds some thickness to the handle, so all other parts must be made very carefully to allow for that.

A similar finish may be achieved with clear, spray lacquer. You must be sure that each layer has dried completely, before adding another. Woods with any natural oil, virtually all of them, will have to be sealed thoroughly, if lacquer is to harden properly. Again, this will add to the thickness of whatever parts it is applied to.

Barry Posner worked out a durable and attractive wood finish, using a floor sealer called Diamond Gloss and it is a non-oxidizing type which should keep the original colors of the wood.

Barry wipes the coat on, with a generous application, rubs it in well, once a day for three days. Each coating is rubbed with steel wool when apparently dry. Then the grip is cured for a week, allowing a complete drying before buffing it. After buffing, Barry applies Minwax, which streaks like crazy at first, and does a final buffing to the finish.

For wood which may be allowed to oxidize, he uses Watco Cherry Oil #5, on the wood sanded to 400 grit, or finer. The coating is left overnight, then steel wool polished. He applies up to four coats this way, working each down with steel wool. The final step is to apply the Minwax as he did with the previous finish.

Sherman Williams had an interesting formula worked out. It seemed to stabilize wood as well as providing an attractive polish.

He used a mixture of, 1/3 "Parks" gloss polyurethane and 2/3 "Sinclare 335 ON Wood Pride Wiping Stain. If this thickened too much, alcohol was added to thin it.

Handles were soaked, dried for about two days, then sanded and buffed.




RUBBER HANDLES

A lot of the S.O.F. crowd like a neoprene grip on a knife. It has to be glued on. If you attach it with bolts or pins, they'll dig into the users hand under severe conditions.

When gluing rubber, do not clamp it hard enough to compress it, and use a good grade of super glue. Do not put any sort of pins or bolts that reach the gripping surface, in a rubber grip. Under severe conditions, the rubber may be pressed down enough to have the sharp edges of the bolt metal cut into a users hand.




MORE HINTS

Taper reamers will do a fine job with bolster pin anchoring. Drill as normal and ream out the hole with the reamer, which, in this size, only cuts a few thousandths of an inch. Go ahead and set the pin as you normally would. The slight taper will hold as well as using a hole with a small step cut in it. Thanks to Clint Breshears.



 

 

 

Engnath
Copyright Bob Engnath 1992

Bob Engnath on Knife Handles
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