Exploring Antique Technologies
by Kary Pardy
Iron, with its beloved black color, strength, and propensity for twists and turns can appeal to collectors across several spectrums. Whether you admire an industrial gear, an elaborate Pennsylvania Dutch hinge, or a scrolling Victorian garden bench, there is something enduring about collecting iron. But how did this metal come to be so precious to us, and for that matter, what does it take to get workable iron and how do we know that we’ve got it and not a black-painted imposter? Get ready to dig into one of the most collectible metals.
After aluminum, iron is the most abundant metal on the planet and could be gathered by its earliest users without mining. Primitive iron users, dating as far back as 3,000 BC, heated naturally gathered iron ore in a charcoal fire and then pounded and shaped (wrought) the mass with a hammer until it became a usable tool. Metallurgists refined and perfected wrought iron’s handling over the years and worked it into the soft, malleable, ductile variety that craftsmen love, the variety that graces the walls and showrooms of primitive collectors across the country. Iron advances and industrialization also brought us cast iron, a more brittle, hard substance due to the higher carbon content involved in its creation.
Cast iron is an alloy, or a mixed metal, and contains carbon and traces of silicon and manganese along with iron ore. Natural iron ore was heated in a blast furnace, then the liquid was cast, or poured and reshaped into “pigs,” or ingots that could then be re-melted and mixed with various other elements and scraps until being ultimately poured into a mold to make a final product. Cast iron was the preferred engineering metal in the 18th and 19th century because it did not require the devotion to hand-hammering that wrought iron did, was heavy and relatively heat and wear resistant, and was quite capable as a tool or a support structure. Cast iron was the first important building metal and was revolutionary in creating the first skyscrapers.
Which is which?
When collecting iron, wrought examples show up most often in primitive tools and decorative items (latches, hinges, hooks, handles, trivets, trammels, candlesticks, etc.). These are items that benefit from a more ductile option or a more personal, individual touch. You can recognize wrought iron by its tapering and lack of uniformity and precision along the edges. Hammer marks are also a great give away.
Cast iron takes the opposite approach. Though sometimes just as artistic as wrought iron, cast iron is by definition produced in molds (be sure to look for visible seams!) and pieces are more easily replicated. This ease, relative cost difference, and durability lends cast iron to industrial products, to engineering and technical uses, and to things that benefit from strength and heaviness, such as door-stops, garden furniture, or architectural elements like balconies and gates. In the mid-twentieth century, developments reduced the brittleness of cast iron, making it even more popular for use in machines.
- Iron is magnetic. The magnet test will set iron apart from gold, brass, and copper
- Is the metal rusting? Iron and iron alloys are the only metals that corrode into what we know of as rust. Copper, for examples, oxidizes differently, into a recognizable green, and tin resists corrosion from water.
Iron vs Steel
Steel is an iron alloy that has overtaken our world. Composed of iron, carbon, and a smattering of other metals, steel is more difficult to tell apart from its iron parent. On industrial items, the presence of welding is typically a clue. Welding cast iron parts together was comparatively difficult and therefore more expensive. Steel items were much easier and more efficient to weld. Also keep an eye open for signs of weakness or corrosion; those are the best indicators that something is iron and not stronger steel.
If you are looking for a more precise method, the most common are unfortunately destructive. One way is to use a chisel and remove a small amount of your metal. If it curls, the metal is steel, and if it chips, it’s iron. Similarly, when you drill iron, it comes away in a dust, whereas steel will produce shavings. Another option is the spark test, in which the metal in question is applied to an abrasive wheel. It takes experience or a helpful guide to tell the difference between the spark patterns, but generally, steel will spark more yellow while iron gives off an orange or red-based spark.
Are you curious to include some of this trend in your collection or decorating? You’re not alone. Collecting antique iron has been on the rise as trends prioritize industrial chic designs or primitive items. Whether it’s repurposed antique iron wheels as wall décor or chairs made out of old tractor seats, the industrial style, and iron, have made comebacks. When watching the auction market, iron brings the highest value as elevator gates, architectural elements, and early American-made items. That said, iron is plentiful and with a little inspiration, can be repurposed into something great. Decorating or collecting cast iron cookware is a good place to start. Examples can be found from all age ranges and at a relatively low price point. With a little effort and care, these pieces can also be used and make visually interesting kitchen displays. As always, please let us know if you have any questions!