Blacksmithing Guide. Blacksmith’s Fire.

Blacksmithing Guide. 

Blacksmith’s Fire.

Today’s “economy of waste” presents craftsmen with an abundance of scrap steel from which to forge useful and beautiful things.

In the light of today’s renaissance of handicrafts the ancient art of blacksmithing takes on a new interest . The modern blacksmith must to perfect their forging skills and knowlenge, learn to do by himself what the old-time blacksmith and his helper did as a trade. 

Anyone who is dexterous by nature can become Experienced Blacksmith. Reveals secrets, How to use the basic techniques and tools to make “things” out of “nothing.” The equipment, tools and the procedure for work are described in this manual.

Fresh coal. Coke. Air grate. Ash release.

Keeping a medium-sized fire clean and effective all day long is one of the more difficult skills for the novice to acquire. Strange to say, what seems at first the least of our problems in the blacksmith’s craft — starting and maintaining the fire — often proves to be a stumbling block for the beginner. But in due time it becomes routine, and experience will cancel out the initial frustration.

In the day-to-day work of blacksmithing, each previous coal fire leaves a remnant of coke, small cinders, and ashes. Smoke and yellow flame indicate the burning of unwanted elements that are not pure carbon.

Coke is what coal becomes after it is heated. Like charcoal, coke lights easily and gives off a blue flame. It makes a “clean” fire. A “dirty” fire (one which still smokes) should not be used in heating steel, since it harms the composition of the steel.

Slag is a melted mix of noncombustible matter in coal. It lumps together at the air grate below the fire, often plugging up the holes and obstructing the flow of air, thus lowering the fire’s required heat. Each time, before starting a fresh fire, remove the slag from the air-grate holes with the point of the poker.

Ashes and small cinders will drop through the air grate into the ash pit below the forge. This built-in ash pit should have an easy-release door so that its contents can be emptied into a metal bucket below, or fall in a heap on the dirt or stone floor. (In these accumulated ashes I often poke a piece of hot steel that needs to be very slowly annealed.)

To start the fire, use a handful of wood chips, or some coke left from a previous fire. Fill the surrounding spaces with ample fresh coal. (If it is in large lumps, break it up into pea-sized pieces.) This surrounding coal is the supply which will be raked into the going fire from time to time to replenish whatever has been consumed. It should be kept wet with the sprinkler can so that the fire will not spread out larger than is needed. Blacksmith coal is expensive, so be economical with it!

Crumple half a sheet of newspaper into a fairly tight ball. Light it, and place the burning wad on the cleared firegrate, holding it flame downward with the poker. Gently crank the air fan with the free hand until the flame is burning well, then crank vigorously. Now let go of the fan and, with the freed hand, rake the ready coke or wood chips (but not the fresh coal) over the flaming wad of paper. The fan meanwhile idles by its own momentum; when cranking is resumed, the paper wad is fanned into still more vigorous flame.

At this stage the greater amount of smoke can now be caught by the smoke-catcher hinged in position over the fire. Some smoke is bound to escape, but will soon change into flame. When the flame breaks through, hinge the smoke-catcher hood out of the way.

Now let the fire become evenly hot before raking in some of the surrounding fresh coal. It is best to rake in only a little of the fresh coal from time to time to avoid smoke emission; a yellow flame that combusts the smoke is preferable to having to use the smoke-catcher too often.

The economical way is to start with a small fire, enlarging it only when specially required.

Gas-fired forges have several disadvantages: noise, excessive steel oxidation and a large fire-grate opening through which small work-pieces become easily lost.

a. Air is a gas composed mainly of two elements: About four-fifths oxygen and one-fifth nitrogen. It is the oxygen that is active in burning or combustion. Combustion is the rapid uniting of oxygen with a substance. Coal and wood are made up largely of the element carbon. When they burn, the carbon in the wood or coal combines with the oxygen of the air. In a similar manner, hot iron oxidizes when exposed to the oxygen of the air, forming iron oxide, or scale.

b. The fuel used for forge fires should be coking coal, as free as possible from sulphur, slate, and other impurities. Any soft coal that crumbles easily into many-sided small particles with bright, shiny surfaces is good smithing coal. However, the best way to learn a coal's coking properties is to try it and see if it cokes. Many blacksmiths do not bank the fire or make a supply of coke for future use. It is not necessary to do so for light work, because an experienced blacksmith can char coal around the rim of the fire as fast as he needs it. The charred coal that the blacksmith is constantly making and using to replenish the fire and to cover the forging while it is heating is soft coke.

c. Proper selection of fuel and care of the fire are essential to first-class work, especially for forge welding and for working tool steels. The bottom of the tuyere is about 5 inches below the hearth to allow sufficient depth of fire below the piece being heated when it is level with the hearth. The pressure of the air blast should be from 2 to 7 ounces per square inch. This low pressure is not liable to injure the mmetal that is being heated since destructive oxidation (scaling) will occur but slowly. The hottest part of the fire is from 5 to 7 inches above the tuyere. Three types of fires are used by the blacksmith; the plain open fire, the side-banked fire, and the hollow fire. Each type may be either oxidizing or reducing, according to the depth of the fire and the strength of the blast. When the fire is so thin that the blast can pass through it before all the oxygen is consumed, the oxy gen will attack the iron and form scale. A fire of this kind is known as an oxidizing fire. A deep fire, in which all the oxygen is consumed by combining with the coal before reaching the metal, is known as a reducing fire. It is slow heating but will not oxidize the metal.

A reasonably thick fire just large enough to surround the piece being heated with glowing coals should always be maintained. Unburned wet coal packed around the fire will keep it from spreading.

(1) The plain open fire (fig. 6) is used for heating flat, wide pieces that cannot be heated in a side-banked fire.

Plain open fire.

(2) The side-banked fire (fig. 7) is generally used.

Side-banked fire.

(3) The hollow fire (fig. 8) is not used extensively but gives an intense heat. An important use of this fire is for forge welding and also for heat treating high-speed tool steel which must be heated to a very high temperature (about 2,200° F.). 

Hollow lire.

Blacksmiths' Coal

The coal we use is always called “blacksmiths’ coal” to distinguish it from household coal. It is more expensive, but with correct use it lasts longer. It also bums hotter. It leaves clinkers (slag) instead of ashes and is therefore cleaner, releasing less ash dust into the air. Whatever its composition in scientific terms, the farmer’s feed-and-fuel stores throughout rural areas that sell this coal always call it “blacksmiths’ coal.” As a rule it is sold in 100-pound sacks. It is this coal that is used by horseshoers (farriers).

Water Dipper

A water dipper can be made from a one-pound coffee can nailed onto a wooden handle (a small tree branch will do). The bottom is punctured, with a fine-pointed ice pick or 1/32-inch nail, with holes about 1/2 inch apart. The dipper is used like a sieve for sprinkling water slowly. As a water quencher it can wet down coal, or the part of the steel that sticks out of the fire, to keep it from overheating, especially when steel is held by hand instead of with tongs.