THE CUTLER'S TOOL SHOP

Article Tools

Print

E-mail

Comments

RSS

COUNTRY SKILLS

You can adapt any number of woodworking tools to shape and polish a blade and to form and attach handles to the tang. But the one knife-making step that few country workshops can handle is the full range of heat-treating. The blade can be tempered—heated to about 500° F and cooled slowly so it will hold an edge but not be so brittle as to shatter—in your kitchen oven. You should get a little $3 oven thermometer to assure that temperatures are correct. But before tempering, the steel must be hardened by heating it to 1500° F, then quenched rapidly. No ordinary kitchen range gets half that hot.

Knife makers heat steel in a smith's coal forge, a gas knife makers oven, or an electric annealing oven that costs $400 to several thousand dollars. Spending that much to make a knife or two is unrealistic, but you can have the hightemperature work done at the local high school metal shop or a metalworking job shop that specializes in heattreating. If you anticipate having to cut and weld steel often enough, you can invest $150 in an oxyacetylene torch set and learn to use it safely and effectively.

I use four $10 propane soldering torches in a temporary knife oven fashioned from loose fire brick with an angle iron lintel over the front opening. The interior space is a foot to a foot and a half wide depending on the blade, six inches deep, and one brickthickness high. With torch nozzles poked through holes filed into end bricks, the oven will generate up to 2500° welding temperature in knife-blank-sized pieces of carbon steel. It can take time to heat large blades, so I keep several fresh bottles of fuel at hand. The fourth torch is mainly used to maintain heat when a tank suddenly goes dry and needs replacing (but not till the nozzle cools).

Long-handled pincers of some sort are needed to handle hot metal. Blacksmith's tongs designed for an open forge are too gross for the little oven. So I use longhandled channel-lock pliers and wide-mouthed welders locking pliers (Vicegrips).

Thick leather gauntlets, leather apron (or thick old clothes), and steel-toed boots are desirable, and shatterproof eye protection is absolutely essential. If you heat flat steel it will warp, and to hammer it flat, you need a good hammer and an anvil. I use a onepound ball-pein hammer and a two-and-a-half-pound blacksmith's cross-pein hammer—and for tough stuff, a short four-pound logsplitting maul. As an anvil for small jobs, I use the flat and small horn of my big six-inch vise (though it is cast from soft steel and will dent under blows from a tempered-face hammer). An 18-inch-length chunk of old trolley rail is better. Scrounge at your local junkyard for anvil material as well as knife stock. Just be sure the anvil is well seated so it won't wobble when struck.

A professional knife maker will refine blanks' shape on a pedestal-mounted, standup belt grinder and large revolving grinding wheels on a high-speed motor. High polish is obtained with felt buffing wheels on a dedicated grinder or arbor, belt driven by an electric motor, and a final fine edge is obtained on an assortment of hand and mechanized honing stones and strops.

RSS | Comments | E-mail | Print