With the steel, forge, hammer, tongs, and grinder, you should be able to complete the blade. Remember as you work on it that perfection is key, there is no excuse for it to be less than perfect. Shoot for a blade about a fourth of an inch thick; a common beginner mistake is to make it too thick. The thinner the blade the better at cutting it will be. Forge slowly, making sure there are no deep marks. Blades that are straight or curved forward almost always look better than ones curved backward. The bevel (slope from the back, or spine, of the blade to the cutting edge) should extend at least three fourths of the way from the edge to the spine before it becomes a level flat section. Make sure the blade is straight. Make the tang (metal portion that extends into the handle from the blade) about half as wide as the blade, and the same or less thickness. The grind should be uniform and flat, not convex, and should be about 1/16 of an inch thick at the cutting edge.
Heat treat in the following manner: Heat until critical temperature (point at which a magnet no longer sticks), then plunge in vegetable oil, stirring back and forth to get as cold as possible as quickly as possible. When cool, check for straightness. If slightly warped, temper with two blocks of steel sandwiching the blade, a clamp lightly holding them together. Every half hour tighten the clamp a little more. Be ready for it to snap. To temper, place in oven at 400 degrees F, for a minimum of two hours, ideally six. When done, cool with water.
Once you're done with heat treating, hand sand it. This is the process that will make your blade look professional instead of a stick of metal with a sharp edge. It takes a long time, but that's ok. Start at 80 grit sandpaper (using wood backing the sandpaper) and work up to at least 400. Now you have a finished blade, minus the sharpening. Now it's time for the handle.
I titled this article Handle Material, because though wood is the dominating material used for knives, there is a range of other materials, such as stacked leather, antler, bone, synthetic materials and the like. However I will use the term wood as it is the most straightforward to work with and the most common choice.
Now for your first few knives, I will go ahead and say the choice of wood does not really matter. Your first knife is not going to be very good (though please, prove me wrong) and the focus is not on the quality of the handle. But, though you can use something like pine for your first few, you'll need to handle better woods (pun intended) as you go on.
So, a good handle will have the following qualities:
- It is tight grained and hard. This both makes for a better finish (a hard wood you can even polish, but a soft wood will not get near that), as well as will not soak up moisture, or shrink and expand. Also, if you burn the tang in, it won't catch fire near as easily. Will explain that process later.
- Is tough and not brittle. Unlike steel, the two qualities are not mutually exclusive for wood, though many woods have one quality and not the other. If you find a new wood that fits the first quality, put it on the anvil and whack it with a hammer a few times, see if it splits easily. Splitting and snapping will happen in the following: pinning and piening (where you tap the pin gently to mushroom the top, locking it into the wood), drilling, and in actual heavy use. The first scenario is where it is most likely to chip or split.
- Has no hidden flaws or cracks. Not much of an issue if you order or buy certain woods, but it is if you cut your own wood. A trick I was told to find these cracks is get a branch of whatever wood you intend to use, find a good concrete flat area, and smash it as hard as you can as many times as you can. Any areas that have hidden cracks or flaws or rotten spots will chip and fly off, and you'll be left with a bunch of sound chunks. Violent, but it works. Small knots and such are ok (the block of Koa I'm giving away), just be aware of them and don't put them on critical areas on the knife.
- Appearance. There is no end to the colors, sheens, curls, burls and designs in different woods. The shape, finish, and use of the knife can all dictate which woods would look best, what adds to the core feeling of the knife. This is where the artist part of the bladesmith comes in, to which I will not delve too much here. To start however, do a bit of research on Spalting, Burl, and Curly Wood.
Curly Hawaiian Koa; the bands have a cat's-eye effect when you move it around
With this said, there are many woods that are fit for knives. Experiment around with local woods. I've used both Manzanita and Oak, which are plentiful where I live, but both have been too brittle for use. Try something, test it, try something new and repeat. Get creative, order some "knife blocks" from ebay and try them out. You can get some really nice woods for quite cheap online, and there are many companies that cater specifically to knifemakers.
As your bladesmithing skills increase, it's always better to trade them rather than try selling them, especially as you have neither a reputation nor guarantee in quality. This way you can also build relationships with the people you trade to, which is very helpful down the road. Wood in particular is a perfect thing to trade for, as the gains will go right back into your knifemaking.
Common knife woods
- Maple. This is what I was recommended to use for my first few blades as it is fairly soft and easy to work, but hard enough to give a good finish, take oil well, and not dirty up. Maple is your best choice for a lighter color handle; most other light woods are too soft. Besides that, it's very tough. Spalted maple is just plain striking in appearance.
- Walnut. A little harder than maple, much darker, and usually has some nice grain design. Easy to work, cheap to buy, and takes a wonderful finish.
- Oak. This is a pretty brittle wood, but depending on where you live is very abundant, and the burl (a misgrowth in the wood that results in a very twisty tight grain pattern) is absolutely stunning. It's very hard and can polish quite well. Very hard to work with.
- Birch. Not something I've used myself, so cannot comment much on it.
Then there are various woods quite a bit more exotic, which are not very hard to get your hands on, such as
- Ironwood (take a tip from me and leave it alone for a good while. It's some of the most beautiful wood you'll see but it's not named Ironwood without a reason)
- Cocobolo (sawdust is fairly toxic; wear a respirator
- Purple Heart (also toxic, but not as much so. Both woods are harmless once finished; it's the smoke and dust that'll hurt you)
- Bog oak. When many woods are soaked in a bog for years, they become very very hard and tough, let alone improvement in appearance. I've found a piece alongside the Sacramento River with ease.
There are several woods of course that are beyond high-end, such as Mammoth tusk (gathered in northern Russia, and yes just as pricey as it sounds) and ivory. Then there are the non-woods, such as antler and synthetic materials. I encourage you to try out different things, experiment, buy a few blocks and so on. There are hundreds of possible woods out there that are very inexpensive. Try 'em out and have fun!