Do you wash cast iron with soap and water?
Cast-iron cookware
Because other cookware cleaning techniques like scouring or washing in a dishwasher can remove or damage the seasoning on a bare cast-iron pan, these pans should not be cleaned like most other cookware. Some chefs advocate never cleaning cast-iron pans at all; simply wiping them out after use, or washing them with hot water and a stiff brush. Others advocate washing with mild soap and water, and then re-applying a thin layer of fat or oil. A third approach is to scrub with coarse salt and a paper towel or clean rag.
Conservation and restoration of shipwreck artifacts
Leather must be washed to remove any ingrained dirt; Its ideal to wash leather with water alone. Depending of the condition of the leather, there are variety of mechanical cleaning techniques that may be used and required. Materials such as soft brushes, water jets, ultrasonic cleaners, and ultrasonic dental tools are effective cleaning tools for leather. When leather is mechanically cleaned with a soft steam of water, soft brushed and sponges can also be used. In the case of consistent impurities, leather can be cleaned by chemical means, with the use of small amounts of non-ionic detergents. The chemical cleaning must be followed with a rinse under a stream of water.
Industrial Revolution
Bar iron was the commodity form of iron used as the raw material for making hardware goods such as nails, wire, hinges, horse shoes, wagon tires, chains, etc. and for structural shapes. A small amount of bar iron was converted into steel. Cast iron was used for pots, stoves and other items where its brittleness was tolerable. Most cast iron was refined and converted to bar iron, with substantial losses. Bar iron was also made by the bloomery process, which was the predominant iron smelting process until the late 18th century.
Cutting fluid
Most metalworking and machining processes can benefit from the use of cutting fluid, depending on workpiece material. Common exceptions to this are cast iron and brass, which may be machined dry (though this is not true of all brasses, and any machining of brass will likely benefit from the presence of a cutting fluid).
Pot washing
Another recent innovation is that of heated soak tanks. These tanks come in various sizes, but all act off the same principles.
The tanks are heated to a temperature of approximately which acts as a catalyst for the chemical reactions whereby the carbon and fats from the heavily soiled pots and pans break down. The chemicals used in these cleaning tanks are non caustic and often biodegradable, with a PH of 10-11. Lightly soiled items can be soaked for a couple of hours, whilst badly burnt pots should be soaked over night. The tanks are known to be used in no less than 20 000 restaurants worldwide.
Scrap
A scrap metal shredder is often used to recycle items containing a variety of other materials in combination with steel. Examples are automobiles and white goods such as refrigerators, stoves, clothes washers etc. These items are labor-intensive to manually sort things like plastic, copper, aluminum and brass. By shredding into relatively small pieces, the steel can easily be separated out magnetically. The non-ferrous waste stream requires other techniques to sort.
Cast-iron cookware
Most bare cast-iron pots and pans are cast as a single piece of metal, including the handle. This allows them to be used on both the stovetop and in the oven. Many recipes call for the use of a cast-iron skillet or pot, especially so that the dish can be initially seared or fried on the stovetop then transferred into the oven, pan and all, to finish baking. Likewise, cast-iron skillets can double as baking dishes. This differs from many other cooking pots, which have varying components that may be damaged by the excessive temperatures of or more.
Washing machine
Removal of soap and water from the clothing after washing was a separate process. First, soap would be rinsed out with clear water. After rinsing, the soaking wet clothing would be formed into a roll and twisted by hand to extract water. The entire process often occupied an entire day of hard work, plus drying and ironing.
Wire brush
The wire brush is primarily an abrasive implement, used for cleaning rust and removing paint. It is also used to clean surfaces and to create a better conductive area for attaching electrical connections, such as those between car battery posts and their connectors, should they accumulate a build-up of grime and dirt. When cleaning stainless steel, it is advisable to use a stainless steel bristle wire brush, as a plain carbon steel brush can contaminate the stainless steel and cause rust spots to appear. Brass bristle brushes are used on softer surfaces or when it is necessary to clean a harder surface without marring it. Brass bristle brushed are also used in potentially flammable environments where non-sparking tools are required. Wire brushes are also used to clean the teeth of large animals, such as crocodiles and pigs. They are also used widely in surface engineering to clean the castings to paint the castings.
Cast iron
The best way of using cast iron for bridge construction was by using arches, so that all the material is in compression. Cast iron, again like masonry, is very strong in compression. Wrought iron, like most other kinds of iron and indeed like most metals in general, is strong in tension, and also tough – resistant to fracturing. The relationship between wrought iron and cast iron, for structural purposes, may be thought of as analogous to the relationship between wood and stone.
Wet wipe
Pre-impregnated industrial-strength cleaning wipes with powerful cleaning fluid that cuts through the dirt as the high performance fabric absorbs the residue Industrial wipes has the ability to clean a vast range of though substances from hands, tools and surfaces, including: grime, grease, oil- & water-based paints & coatings, adhesives, silicone & acrylic sealants, poly foam, epoxy, oil, tar and more.
Pot washing
The classic and “old” process for cleaning pots and pans is the manual hand-washing method. Washing pots and pans by hand is still the ideal way to do the job. Cleaning by hand involves a pot-washing sink, which almost always is divided into 3 different sections. The first section, or "sink", is where the pots are washed and scrubbed. The middle section is for rinsing and the third for sanitizing.
Cast iron
Carbon (C) ranging from 1.8 to 4 wt%, and silicon (Si) 1–3 wt% are the main alloying elements of cast iron. Iron alloys with lower carbon content (~0.8%) are known as steel. While this technically makes the Fe–C–Si system ternary, the principle of cast iron solidification can be understood from the simpler binary iron–carbon phase diagram. Since the compositions of most cast irons are around the eutectic point (lowest liquid point) of the iron–carbon system, the melting temperatures usually range from , which is about lower than the melting point of pure iron of .
Cast iron
Because cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. It is strong under compression, but not under tension. Cast iron was invented in China in the 5th century BC and poured into moulds to make ploughshares and pots as well as weapons and pagodas. Although steel was more desirable, cast iron was cheaper and thus was more commonly used for implements in ancient China, while wrought iron or steel was used for weapons. The Chinese developed a method of annealing cast iron by keeping hot castings in an oxidizing atmosphere for a week or longer in order to burn off some carbon near the surface in order to keep the surface layer from being too brittle.
Boiler
Cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are usually termed "boilers" in some countries, their purpose is usually to produce hot water, not steam, and so they run at low pressure and try to avoid boiling. The brittleness of cast iron makes it impractical for high-pressure steam boilers.
Pot washing
Pot washing is the process of cleaning low to heavily baked-on items off of restaurant kitchen food equipment, including pots, pans, trays, tubs and more.
Steel
Plain carbon-iron alloys with a higher than 2.1% carbon content are known as cast iron. With modern steelmaking techniques such as powder metal forming, it is possible to make very high-carbon (and other alloy material) steels, but such are not common. Cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties. Certain compositions of cast iron, while retaining the economies of melting and casting, can be heat treated after casting to make malleable iron or ductile iron objects. Steel is distinguishable from wrought iron (now largely obsolete), which may contain a small amount of carbon but large amounts of slag.
Wrought iron
Wrought iron lacks the carbon content necessary for hardening through heat treatment, but in areas where steel was uncommon or unknown, tools were sometimes cold-worked (hence cold iron) in order to harden them. An advantage of its low carbon content is its excellent weldability. Furthermore, sheet wrought iron cannot bend as much as steel sheet metal (when cold worked). Wrought iron can be melted and cast, however the product is no longer wrought iron, since the slag stringers characteristic of wrought iron disappear on melting, so the product resembles impure cast Bessemer steel. There is no engineering advantage as compared to cast iron or steel, both of which are cheaper.
Surface chemistry of cooking
Cast iron cookware is seasoned with oil. The surface of the cast iron is not very smooth; it has pits and peaks that are not conducive to cooking. Typically, the cookware is seasoned with oil. This process leaves a thin coat of oil in the pits and on top of the peaks on the surface of the pan. This thin coat actually polymerizes, making it durable and lasting. It also prevents the cast iron from rusting, which it is prone to do. The oil that is used in a seasoned pan combines with any liquid that is used in the cooking process and creates a good contact between pan and food. Even though the cast iron itself is a poor heat conductor, the oil makes the pan effective when it is at a high temperature.
Dishwashing
Dish washing is usually done using an implement for the washer to wield, unless done using an automated dishwasher. Commonly used implements include cloths, sponges, brushes or even steel wool. As fingernails are often more effective than soft implements like cloths at dislodging hard particles, washing simply with the hands is also done and can be effective as well. Dishwashing detergent is also generally used, but bar soap can be used acceptably, as well. Rubber gloves are often worn when washing dishes by people who are sensitive to hot water or dish-washing liquids. According to dermatologists, the use of protective gloves is highly recommended whenever working with water and cleaning products, since some chemicals may damage the skin, or allergies may develop in some individuals. Dish gloves are also worn by those who simply don't want to touch the old food particles. Many people also wear aprons.
Iron
Wrought iron contains less than 0.25% carbon but large amounts of slag that give it a fibrous characteristic. It is a tough, malleable product, but not as fusible as pig iron. If honed to an edge, it loses it quickly. Wrought iron is characterized by the presence of fine fibers of slag entrapped within the metal. Wrought iron is more corrosion resistant than steel. It has been almost completely replaced by mild steel for traditional "wrought iron" products and blacksmithing.
Mild steel corrodes more readily than wrought iron, but is cheaper and more widely available. Carbon steel contains 2.0% carbon or less, with small amounts of manganese, sulfur, phosphorus, and silicon. Alloy steels contain varying amounts of carbon as well as other metals, such as chromium, vanadium, molybdenum, nickel, tungsten, etc. Their alloy content raises their cost, and so they are usually only employed for specialist uses. One common alloy steel, though, is stainless steel. Recent developments in ferrous metallurgy have produced a growing range of microalloyed steels, also termed 'HSLA' or high-strength, low alloy steels, containing tiny additions to produce high strengths and often spectacular toughness at minimal cost.
Apart from traditional applications, iron is also used for protection from ionizing radiation. Although it is lighter than another traditional protection material, lead, it is much stronger mechanically. The attenuation of radiation as a function of energy is shown in the graph.
Conservation and restoration of bone, horn, and antler objects
If dusting alone is not enough, smooth materials are then cleaned with water and mild soap. A cotton swab is used to apply a soapy solution sparingly. The surface can not remain damp longer than a few seconds and will immediately be dried with a soft tissue or another cotton swab. The same area will be cleaned again in the same manner to remove any soap film. If the surface is cracked or porous, water will not be applied. Bone should never be soaked.
Dishwashing liquid
Hand dishwashing is generally performed in the absence of a dishwashing machine, when large "hard-to-clean" items are present, or through preference. Some dishwashing liquids can harm household silver, fine glassware, anything with gold leaf, disposable plastics, and any objects made of brass, bronze, cast iron, pewter, tin, or wood, especially when combined with hot water and the action of a dishwasher. When dishwashing liquid is used on such objects it is intended that they be washed by hand.
Galvanic corrosion
The common technique of cleaning silverware by immersion of the silver and a piece of aluminum in an electrolytic bath (usually sodium bicarbonate) is an example of galvanic corrosion. The process involves electrochemical reduction of silver sulfide molecules (generally speaking, silver is not easily corroded by oxygen). Sulfur atoms are stripped off the silver sulfide, transferring them onto and thereby corroding a piece of aluminum foil (a much more reactive metal), leaving pure silver behind. No silver is lost in the process.
Window shutter hardware
Wrought Iron - literally "hammered" iron. Early on, billets of cast iron were transferred to iron forges. The cast iron billets were heated to near-molten and flattened under a heavy water-powered drop hammer - kind of a see-saw with a couple of hundred pound chunk of iron "hammer" on one end of a heavy wooden beam and a rotating wooden cam acting on the other end to lift and drop the hammer in time with the turning of the water wheel. Valley Forge took its name from a small shop such as this which the British burned, unopposed, on their way to Philadelphia in 1776. Once hammered thinner and longer the billet would be doubled backed on its length, re-heated and re-hammered. This repeated exposure to the oxygen in the fire and the compressing blows of the hammer would burn and drive impurities from the billet. The iron being forged would become increasingly malleable with each heat to which it was subjected. The finest forging iron was multi-layered and nearly pure iron. To the best of my knowledge, there is no new wrought iron being produced today. Well, maybe Japanese Samurai swordsmiths still make their own – but if it's in Home Depot and says "Wrought Iron" it isn't.
Direct bonding
Before bonding two wafers, those two solids need to be free of impurities that can base on particle, organic and/or ionic contamination. To achieve the cleanliness without degrading the surface quality, the wafer passes a dry cleaning, e.g. plasma treatments or UV/ozone cleaning, or a wet chemical cleaning procedure.
The utilization of chemical solutions combines sequential steps. An established industrial standard procedure is SC (Standard Clean) purification by RCA. It consists of two solutions
SC1 is used for removing organic contaminations and particles at a temperature of 70 °C to 80 °C for 5 to 10 min and SC2 is used for removing metal ions at 80 °C for 10 min.
Subsequently, the wafers are rinsed with or stored in deionized water. The actual procedure needs to be adapted to every application and device because of usually existing interconnects and metallization systems on the wafer.
List of cast-iron cookware manufacturers
Milo is a Los Angeles based company that manufactures kitchen essentials. They launched in 2018 with a cast iron enameled Dutch Oven. They sell exclusively online from their website and have a lifetime warranty on their products.
Field Skillets are manufactured in Wisconsin and Indiana and the focus is on creating lighter weight cast iron. The pans have a smooth finish.
Several companies import cast-iron cookware of Chinese manufacture and market these products in America. Known American marketers of Chinese cast-iron cooking equipment include Bayou Classic, Camp Chef, Coleman, Old Mountain and Texsport.
Wash copper
A wash copper, copper boiler or simply copper is a wash house boiler, generally made of galvanised iron, though the best sorts are made of copper. In the inter-war years they came in two types. The first is built into a brickwork furnace and was found in older houses. The second was the free-standing or portable type, it had an enamelled metal exterior that supported the inner can or copper. The bottom part was adapted to hold a gas burner, a high pressure oil or an ordinary wood or coal fire. Superior models could have a drawing-off tap, and a steam-escape pipe that lead into the flue.
It was used for domestic laundry. Linen and cotton were placed in the copper and were boiled to whiten them. Clothes were agitated within the copper with a washing dolly, a vertical stick with either a metal cone or short wooden legs on it. After washing, the laundry was dried with a mangle and then line-dried.
Vinegar
White vinegar is often used as a household cleaning agent. For most uses, dilution with water is recommended for safety and to avoid damaging the surfaces being cleaned. Because it is acidic, it can dissolve mineral deposits from glass, coffee makers, and other smooth surfaces. Vinegar is known as an effective cleaner of stainless steel and glass. Malt vinegar sprinkled onto crumpled newspaper is a traditional, and still-popular, method of cleaning grease-smeared windows and mirrors in the United Kingdom.
Water quality
Dissolved minerals may affect suitability of water for a range of industrial and domestic purposes. The most familiar of these is probably the presence of ions of calcium (Ca) and magnesium (Mg) which interfere with the cleaning action of soap, and can form hard sulfate and soft carbonate deposits in water heaters or boilers. Hard water may be softened to remove these ions. The softening process often substitutes sodium cations. Hard water may be preferable to soft water for human consumption, since health problems have been associated with excess sodium and with calcium and magnesium deficiencies. Softening decreases nutrition and may increase cleaning effectiveness. Various industries' wastes and effluents can also pollute the water quality in receiving bodies of water.
Cast-iron cookware
A proper cast iron seasoning protects the cookware from rusting, provides a non-stick surface for cooking, and reduces food interaction with the iron of the pan. However, exposure to acidic foods such as tomatoes removes the seasoning, and the cookware must be re-seasoned again. Enamel-coated cast-iron pans do not need seasoning, as the enamel coating prevents rust in most instances. It is recommended to maintain the seasoning frequently to keep the food from sticking to the iron.
Window shutter hardware
Cast Iron - the product extracted from iron ore. Iron oxide-rich ore is heated to a molten state in the presence of limestone within a large flask. Oxygen makes a chemical transition from the iron oxides to the calcium forming a "slag" which floats to the top of an increasingly iron-rich molten pool. When done, the bottom of the flask is opened and the iron pours out - historically into sand patterns to produce cast iron stoves and such, or into troughs on the foundry floor to form rough billets. The billets could be re-melted and cast into shapes at other foundries or could be hammered into wrought iron in forges. Good news is cast iron flows easily into molds and can be used to quickly form intricate articles from iron. The bad news is that cast iron is brittle and cracks rather than bends. Brittle because it is not pure iron - impurities are not completely leached from the ore and carbon from the heating fuel is absorbed into the iron pool. Quick cooling of the iron in a mold also increases brittleness – smaller, thinner pieces (like hinges) are usually more brittle than larger, heavier pieces (like machines) that "hold their heat" when poured and thus take longer to cool.
Cast iron pipe
Cast iron pipe is a pipe which has had historic use as a pressure pipe for transmission of water, gas and sewage, and as a water drainage pipe during the 19th and 20th centuries. It comprises predominantly a gray cast iron tube and was frequently used uncoated, although later coatings and linings reduced corrosion and improve hydraulics. Cast iron pipe was superseded by ductile iron pipe, which is a direct development, with most existing manufacturing plants transitioning to the new material during the 1970s and 1980s. Little cast iron pipe is currently manufactured.
Wrought iron
Wrought iron is an iron alloy with a very low carbon (less than 0.08%) content in contrast to cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which gives it a "grain" resembling wood that is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile, corrosion-resistant and easily welded. Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. It was given the name "wrought" because it was hammered, rolled or otherwise worked while hot enough to expel molten slag. The modern functional equivalent of wrought iron is mild or low carbon steel. Neither wrought iron nor mild steel contain enough carbon to be hardenable by heating and quenching.
Cast-iron cookware
While enamel-coated cast iron doesn't have the seasoning and cleaning issues of bare cast iron, a similar style of enamel-coated cast iron can cost three or four times its bare cast iron counterpart. For those seeking to reduce iron in their diet, enameled cast iron limits the leaching of dietary iron into food. However, some of the benefits of bare cast iron, such as the ability to withstand searing heat and resist sticking, are lost through enameling. In addition, chipping of the enamel coating can occur if the pan is dropped, overheated, or cold water is added to a hot pot.
Citric acid
Citric acid is an excellent chelating agent, binding metals by making them soluble. It is used to remove and discourage the buildup of limescale from boilers and evaporators. It can be used to treat water, which makes it useful in improving the effectiveness of soaps and laundry detergents. By chelating the metals in hard water, it lets these cleaners produce foam and work better without need for water softening. Citric acid is the active ingredient in some bathroom and kitchen cleaning solutions. A solution with a six percent concentration of citric acid will remove hard water stains from glass without scrubbing. Citric acid can be used in shampoo to wash out wax and coloring from the hair.
Copper sheathing
In the late 18th to early 19th century, Sir Humphry Davy performed many experiments to determine how to lessen the corrosion that the seawater caused on unprotected copper sheathing.
To this end he had various thicknesses of copper submerged on the shore and then measured how much the sea water had degraded each one. Sheets of different metals remained in the seawater for four months and then were examined. Two harbour ships were also used in this test, one with an additional zinc band, the other with an iron one. Davy observed, that while the zinc and iron themselves became covered in carbonate that allowed weeds, plant life and insects to attach themselves to the metal, the copper sheets that were connected to cast iron or zinc parts were free of any attached life forms or discoloration.
Unprotected copper would quickly go from a reddish color to a greenish color of corrosion.
When the other metals were mixed with copper in ratios from 1:40 to 1:150, there was no visible sign of corrosion and minimal weight loss. When the ratio was changed to 1:200 and 1:400, there was significant corrosion and weight loss.
Davy therefore advocated cast iron for protecting copper, since it was the cheapest to manufacture, and in his observations malleable iron and zinc seemed to wear down faster.
Soldering iron
A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current (supplied through an electrical cord or battery cables) through a resistive heating element. Cordless irons can be heated by combustion of gas stored in a small tank, often using a catalytic heater rather than a flame. Simple irons less commonly used today than in the past were simply a large copper bit on a handle, heated in a flame.
Mop
The "hot mop" (or steam mop) follows a similar concept to a steam iron. After adding water, the water is heated to make it exude on top of a floor, which can then be cleaned without using a cleaning solvent. These can work best on surfaces where a regular mop would also be used, such as bare floors, hearths, and laminate.
Iron
α-Iron is a fairly soft metal that can dissolve only a small concentration of carbon (no more than 0.021% by mass at 910 °C). Austenite (γ-iron) is similarly soft and metallic but can dissolve considerably more carbon (as much as 2.04% by mass at 1146 °C). This form of iron is used in the type of stainless steel used for making cutlery, and hospital and food-service equipment.
Cast-iron cookware
Today, of the large selection of cookware that can be purchased from kitchen suppliers, cast iron comprises only a small fraction. However, the durability and reliability of cast iron as a cooking tool has ensured its survival. Lodge, Wagner and Griswold cast-iron pots and pans from the 19th and 20th century continue to see daily use to the present day. They are also highly sought after by antique collectors and dealers.
Conservation and restoration of parchment
If their presence is determined upon examination, insects and pests are eliminated and the parchment disinfected. An appropriate round of fumigation in an autoclave is used to remove pests and sterilize the object. Dry and wet cleaning techniques can both be used effectively on parchment objects. Mechanical cleaning using erasers and other abrasive tools is used to remove mildew and dirt. Surface cleaning of parchment is typically completed using white vinyl erasers (solid and grated) and confined to areas where no media is present. Water baths, which sometimes use neutral detergents or alcohol as additives, can be used to clean as well as prepare the parchment for stretching as part of the conservation process. Another wet cleaning method, which is especially useful for removing mold and mildew, uses a cotton swab covered in fluid, usually denatured alcohol, ethanol or saliva. Laser cleaning may provide a non-contact cleaning process, though conservation labs throughout Europe still mostly use traditional wet and dry cleaning methods for parchment.
Electrolysis
Electrolysis is also used in the cleaning and preservation of old artifacts. Because the process separates the non-metallic particles from the metallic ones, it is very useful for cleaning a wide variety of metallic objects, from old coins to even larger objects including rusted cast iron cylinder blocks and heads when rebuilding automobile engines. Rust removal from small iron or steel objects by electrolysis can be done in a home workshop using simple materials such as a plastic bucket, tap water, lengths of rebar, washing soda, baling wire, and a battery charger.
Hairstyle
Curling and straightening hair requires the stylist to use a curling rod or a flat iron to get a desired look. These irons use heat to manipulate the hair into a variety of waves, curls and reversing natural curls and temporarily straightening the hair. Straightening or even curling hair can damage it due to direct heat from the iron and applying chemicals afterwards to keep its shape.
There are irons that have a function to straighten or curl hair even when its damp (from showering or wetting the hair), but this requires more heat than the average iron (temperatures can range from 300–450 degrees). Heat protection sprays and hair-repairing shampoos and conditioners can protect hair from damage caused by the direct heat from the irons.
Testing and inspection of diving cylinders
Before inspection the cylinder must be clean and free of loose coatings, corrosion products and other materials which may obscure the surface. Foreign materials may be removed by brushing, controlled shot-blasting, water-jet cleaning chemical cleaning or other non-destructive methods. The method used must not remove a significant amount of cylinder material, and steel cylinders may not be heated above 300°C. Aluminium cylinders are even more restricted in the temperatures permitted, which are specified by the manufacturer.
Iron
The main disadvantage of iron and steel is that pure iron, and most of its alloys, suffer badly from rust if not protected in some way, a cost amounting to over 1% of the world's economy. Painting, galvanization, passivation, plastic coating and bluing are all used to protect iron from rust by excluding water and oxygen or by cathodic protection. The mechanism of the rusting of iron is as follows:
Conservation and restoration of lighthouses
Basic preservation of lighthouse masonry usually includes gentle surface cleaning. Appropriate methods for cleaning are determined by the type of masonry that exists on the building. Some cleaning methods include water, chemical, and laser. There are multiple water cleaning methods. Soaking is a process where the masonry undergoes a prolonged exposure to misting water to remove dirt. Water washing uses a light to medium pressurized stream of water. Some water washing may use the addition of detergents to increase dirt removal. Chemical cleaning is also an option, but may be too harsh depending on the makeup of the masonry. Chemical cleaners are either acidic or alkaline. Laser cleaning is effective, mostly on smaller areas of masonry, but can be costly. Occasionally, a lighthouse may be weatherproofed through covering the masonry with paint, stucco, or whitewash/lime mortar wash; but only if these are historically accurate for the structure. Due to the differences in materials and construction techniques, only an experienced architectural conservator should be contacted for conservation or restoration work.
Cast-iron cookware
Cast-iron cookware is valued for its heat retention properties and can be produced and formed with a relatively low level of technology. Seasoning is used to protect bare cast iron from rust and to create a non-stick surface. Types of bare cast-iron cookware include panini presses, waffle irons, crepe makers, dutch ovens, frying pans, deep fryers, tetsubin, woks, potjies, karahi, flattop grills and griddles.
Cast iron
Cast iron is made from pig iron, which is the product of smelting iron ore in a blast furnace. Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to the melt before the final form is produced by casting.
Ferrous metallurgy
The earliest cast iron artifacts, dating to 5th century BC, were discovered by archaeologists in what is now modern Luhe County, Jiangsu in China. Cast iron was used in ancient China for warfare, agriculture and architecture. Around 500 BC, metalworkers in the southern state of Wu achieved a temperature of 1130 °C. At this temperature, iron combines with 4.3% carbon and melts. The liquid iron can be cast into molds, a method far less laborious than individually forging each piece of iron from a bloom.
Parts washer
An aqueous-based parts washer is much like a large dish washer. It uses water and detergent combined with heat and mechanical energy to provide the cleaning action. There are two main process styles of aqueous parts washers, the "jet spray process" and the "power wash process". In a cabinet parts washer, the parts are placed on a turntable and the door is closed. During the cleaning cycle heated solution is flooded or blasted on the parts as the turntable rotates. Many systems have a wash, rinse and dry cycle. When the cycle is complete the door is opened and the parts removed.
Bluing (steel)
Bluing is also used in seasoning cast-iron cookware, to render it relatively rust-proof and non-stick. In this case cooking oil, rather than gun oil, acts to displace water and prevent rust.
Wrought iron
Wrought iron may be welded in the same manner as mild steel, but the presence of oxide or inclusions will give defective results.
The material has a rough surface, so it can hold platings and coatings better. For instance, a galvanic zinc finish applied to wrought iron is approximately 25–40% thicker than the same finish on steel. In Table 1, the chemical composition of wrought iron is compared to that of pig iron and carbon steel. Although it appears that wrought iron and plain carbon steel have similar chemical compositions, that is deceiving. Most of the manganese, sulfur, phosphorus, and silicon are incorporated into the slag fibers present in the wrought iron, so, really, wrought iron is purer than plain carbon steel.
Stone washing
Stone washing is a textile manufacturing process used to give a newly manufactured cloth garment a worn-in (or worn-out) appearance. Stone-washing also helps to increase the softness and flexibility of otherwise stiff and rigid fabrics such as canvas and denim.
Metal stitching
Metal stitching is an industrial technique for repairing cracked and broken cast iron, steel, bronze or aluminium structures and their components. The process, is carried out cold, without welding. It allows the repair of cast iron and cast steel, often in-situ, without the distortion from welding, and can be used in other situations where heat cannot be used to achieve a repair.
Carpet cleaning
Although there is an actual steam cleaning industrial process, in the context of carpet cleaning, "steam cleaning" is often mistaken for hot water soil extraction cleaning, which is professionally known as HWE. The hot water soil extraction cleaning method uses equipment that sprays heated water and detergent on the carpet and simultaneously, the water and detergent is extracted, along with any dislodged and dissolved dirt. Many carpet manufacturers recommend professional hot water extraction as the most effective carpet cleaning method which also provides a deeper clean. Actual steam could damage man-made carpet fibers and change the characteristics as they are usually set using heat. Woven carpets can shrink but most carpets are not woven and are in fact tuffed on a laminate backing, velvet-piled carpets and Berber carpets may become fuzzy which is known as pile burst. Most problems can be avoided by professional experienced cleaners.
Wood stain
There are special consideration when cleaning stained wood. One of the most common stains is water stains on stained wood. Techniques to remove the water stains have been documented that use a hot iron to remove the water stain.
Rust
When impure (cast) iron is in contact with water, oxygen, other strong oxidants, or acids, it rusts. If salt is present, for example in seawater or salt spray, the iron tends to rust more quickly, as a result of electrochemical reactions. Iron metal is relatively unaffected by pure water or by dry oxygen. As with other metals, like aluminium, a tightly adhering oxide coating, a passivation layer, protects the bulk iron from further oxidation. The conversion of the passivating ferrous oxide layer to rust results from the combined action of two agents, usually oxygen and water.
Ironing
Commercial dry cleaning and full-service laundry providers usually use a large appliance called a steam press to do most of the work of ironing clothes. Alternatively, a rotary iron may be used.
Historically, larger tailors' shops included a tailor's stove, used to quickly and efficiently heat multiple irons. In many developing countries a cluster of solid irons, heated alternatively from a single heating source, are used for pressing clothes at small commercial outlets.
Wok
Currently, carbon steel is the most widely used material, being relatively inexpensive compared with other materials, relatively light in weight, providing quick heat conduction, and having reasonable durability. Their light weight makes them easier to lift and quicker to heat. Carbon steel woks, however, tend to be more difficult to season than those made of cast-iron ('seasoning', or carbonizing the cooking surface of a wok, is required to prevent foods from sticking and to remove metallic tastes and odors). Carbon steel woks vary widely in price, style, and quality, which is based on ply and forming technique. The lowest quality steel woks tend to be stamped by machine from a single 'ply' or piece of stamped steel. Less expensive woks have a higher tendency to deform and misshape. Cooking with lower quality woks is also more difficult and precarious since they often have a "hot spot". Higher quality, mass-produced woks are made of heavy gauge (14-gauge or thicker) steel, and are either machine-hammered or made of spun steel. The best quality woks are almost always hand-made, being pounded into shape by hand ("hand hammered") from two or more sheets of carbon steel which are shaped into final form by a ring-forming or hand-forging process.
Iron
Commercially available iron is classified based on purity and the abundance of additives. Pig iron has 3.5–4.5% carbon and contains varying amounts of contaminants such as sulfur, silicon and phosphorus. Pig iron is not a saleable product, but rather an intermediate step in the production of cast iron and steel. The reduction of contaminants in pig iron that negatively affect material properties, such as sulfur and phosphorus, yields cast iron containing 2–4% carbon, 1–6% silicon, and small amounts of manganese. Pig iron has a melting point in the range of 1420–1470 K, which is lower than either of its two main components, and makes it the first product to be melted when carbon and iron are heated together. Its mechanical properties vary greatly and depend on the form the carbon takes in the alloy.
Portable water purification
Common metallic contaminants such as copper and lead can be treated by increasing the pH using soda ash or lime, which precipitates such metals. Careful decanting of the clear water after settlement or the use of filtration provides acceptably low levels of metals. Water contaminated by aluminium or zinc cannot be treated in this way using a strong alkali as higher pHs re-dissolve the metal salts. Salt is difficult to remove except by reverse osmosis or distillation.
Cast iron
Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its colour when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing.
Washdown
Washdown is the process of using a stream of water to clean a flat or nearly flat outside surface. Typically the area cleaned is a large expanse of concrete or asphalt. The area is cleaned of dirt and debris by the use of the force and dissolving power of stream of water as projected from a hose. Generally, one person holds and aims the hose, though if the hose is longer than 300 feet then another person may be required to help move the hose itself. Water is typically squirted from the hose at a pressure of 300 psi. The hose itself can vary in length from 75 to 425 feet. Though typically the hose when used by a single person is 300 feet long. The hose itself carries water from a water main which attaches to the hose through what is called a “stinger“. The stinger screws into the water main pipe and is held there.
Iron ore
In cast iron sulfur promotes the formation of white iron. As little as 0.5% can counteract the effects of slow cooling and a high silicon content . White cast iron is more brittle, but also harder. It is generally avoided, because it is difficult to work, except in China where high sulfur cast iron, some as high as 0.57%, made with coal and coke, was used to make bells and chimes . According to , good foundry iron should have less than 0.15% sulfur. In the rest of the world a high sulfur cast iron can be used for making castings, but will make poor wrought iron.
Steel casting
Cast parts often require machining to achieve accurate tolerances and desired surface finishes. Carbon steel is the easiest type of steel to machine. High-carbon steel can be more time consuming to cut or grind, and will wear tools faster. Low-carbon steel can get gummy, making it difficult to work with.
Sink
Stainless steel is commonly used in kitchens and commercial applications because it represents a good trade-off between cost, usability, durability, and ease of cleaning. Most stainless steel sinks are made by drawing a sheet of stainless steel over a die. Some very deep sinks are fabricated by welding. Stainless steel sinks will not be damaged by hot or cold objects and resist damage from impacts. One disadvantage of stainless steel is that, being made of thin metal, they tend to be noisier than most other sink materials, although better sinks apply a heavy coating of vibration-damping material to the underside of the sink.
Castile soap
Importations of "Castile soap" through Antwerp appear in the London port books of 1567–1568, though the "Oxford English Dictionary" has no references to "Castile soap" earlier than 1616. In his article "A short history of soap", John Hunt maintains that "barilla" (an impure form of sodium carbonate obtained from halophyte plant ashes that were high in sodium) was boiled with locally available olive oil, rather than tallow.
Parts washer
A jet spray washer cleans by flooding the parts with warm chemical solution and high chemical concentration to clean the parts. In the power wash process the parts are blasted with hot chemical solution utilizing the hydraulic impact force of the cleaning solution as the primary cleaning mechanism. A parts washer utilizing the power washer process operates at a very low concentration of cleaning detergent. The lower concentration causes the cleaning solution to last longer before it becomes supersaturated and requires disposal. Additionally, a low concentration of cleaning chemicals allows for easier rinsing of the detergent from the parts thereby minimizing rinse cycle requirements thus saving water and cycle time. A final factor used in the power wash process is an oscillating manifold system that is non-synchronous to the rotation of the turntable. This system assures that the blasted solution reaches all areas of the parts load that are otherwise blinded by the stationary manifolds used in the jet spray process. All things considered the power wash process is superior to the jet spray process for faster more thorough parts cleaning cycles while minimizing detergent use and waste generation. The power wash process is generally effective for difficult soil removal applications such as burnt hydrocarbons, paint, scale, varnish, carbon, mastic, or rubber. Additional power wash types of applications generally include cleaning diesel engines, aerospace components, aluminum automobile engine parts and rolling mill equipment.
SoHo, Manhattan
During cast iron's heyday, many architects thought it to be structurally more sound than steel. It was also thought that cast iron would be fire-resistant, and facades were constructed over many interiors built of wood and other flammable materials. When exposed to heat, cast iron buckled, and later cracked under the cold water used to extinguish fire. In 1899, a building code mandating the backing of cast-iron fronts with masonry was passed. Most of the buildings that stand today are constructed in this way. It was the advent of steel as a major construction material that brought an end to the cast iron era.
Steel wool
Steel wool is often used for professional cleaning processes on glass and porcelain because it is softer than those materials and is able to scrape off deposits without scratching the underlying surface like common abrasives. In many countries, soap-impregnated steel wool pads were sold under various trade names for household cleaning, although those products sometimes no longer contain steel wool.
Ironing
The iron is the small appliance used to remove wrinkles from fabric. It is also known as a clothes iron, flat iron, or smoothing iron.
Most ironing is done on an ironing board, a small, portable, foldable table with a heat-resistant surface. Some commercial-grade ironing boards incorporate a heating element and a pedal-operated vacuum to pull air through the board and dry the garment.
Hand washing
One must use soap and warm running water if possible and wash all the skin and nails thoroughly. However, ash can substitute for soap (see substances above) and cold water can also be used.
Sanitation
In the food and biopharmaceutical industries, the term "sanitary equipment" means equipment that is fully cleanable using clean-in-place (CIP) and sterilization-in-place (SIP) procedures: that is fully drainable from cleaning solutions and other liquids. The design should have a minimum amount of deadleg, or areas where the turbulence during cleaning is insufficient to remove product deposits. In general, to improve cleanability, this equipment is made from Stainless Steel 316L, (an alloy containing small amounts of molybdenum). The surface is usually electropolished to an effective surface roughness of less than 0.5 micrometre to reduce the possibility of bacterial adhesion.
William Kelly (inventor)
Kelly started experimenting with his "air-boiling process," a process of blowing air up through molten iron to reduce the carbon content, in the 1850s. His initial goal was to reduce the amount of fuel required for iron and steel making, because of the immense amount of timber required to make the charcoal. He discovered that the injected air did not cool the molten iron, but instead combined with the carbon to cause the iron to boil and burn violently until the carbon was greatly reduced, improving the quality of the iron or converting it to steel. His iron workers may have contributed to his discovery. According to Kelly's biography, in 1854 he hired Chinese iron workers through a New York teahouse. Historian of metallurgy Donald Wagner notes that a similar process was already extant in China, and that Kelly's Chinese iron workers were likely familiar with how molten cast iron behaved under an air blast. The engineer William Phillips, after a trip to Eddyville, wrote in 1899 that "the Chinese had refined iron by blowing air into it a great many years ago, and I have thought that Kelly, in asking for Chinese laborers, would naturally require the services of those who had some knowledge of the iron business."
Fusion bonded epoxy coating
It is important to remove grease or oil contamination prior to blast cleaning. Solvent cleaning, burn-off, etc., are commonly used for this purpose. In the blast cleaning process, compressed air (90 to 110 psi/610 to 760 kPa) is used to force dan abrasive onto the surface to be cleaned. Aluminum oxide, steel grit, steel shot, garnet, coal slag, etc., are the frequently used abrasives. Another method of blast cleaning is centrifugal blast cleaning, which is especially used in cleaning the exterior of pipe. In this method, abrasive is thrown to the rotating pipe body, using a specially designed wheel, which is rotated at high speed, while the abrasive is fed from the centre of the wheel.
Seasoning (cookware)
Some form of post-manufacturing treatment or end-user seasoning is mandatory on cast-iron cookware, which rusts rapidly when heated in the presence of available oxygen, notably from water, even small quantities such as drippings from dry meat. Food tends to stick to unseasoned iron and carbon steel cookware, both of which are seasoned for this reason as well.
Cast iron
Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are used in pipes, machines and automotive industry parts, such as cylinder heads (declining usage), cylinder blocks and gearbox cases (also declining usage). It is resistant to destruction and weakening by oxidation.
Conservation and restoration of shipwreck artifacts
Iron and copper oxide stains occur when oxidized metals are located near or in contact with a ceramic or stone object and metal oxide particles pass to the structure of the stone or ceramic. Iron and copper oxides can penetrate deep into the pores of ceramics and stones and create reddish-brown to black stains (iron oxide) and blue-green stains (copper oxides). The use of EDTA salt solution can be used to remove the oxides. A mild solution consists of 3% to 5% of EDTA; 15% to 20% solution in water on ceramics to remove the stains. Iron oxides can be removed from the objects by the use of water in a 10% to 25% solution of hydrogen peroxide. The time required to remove the stains can vary from a few seconds to several hours.
Dishwashing
Dishwashing or dish washing, also known as washing up, is the process of cleaning cooking utensils, dishes, cutlery and other items to prevent foodborne illness. This is either achieved by hand in a sink using dishwashing detergent or by using a dishwasher and may take place in a kitchen, utility room, scullery or elsewhere. In Britain to do the washing up also includes to dry and put away. There are cultural divisions over rinsing and drying after washing.
Dutch oven
After use Dutch ovens are typically cleaned like other cast-iron cookware: with boiling water, and a soft brush or sponge. Where possible, a cleaned and freshly oiled Dutch oven should be stored in a clean, dry location with the lid ajar or off to promote air circulation and to avoid the smell and taste of rancid oil. If the Dutch oven must be stored with the lid on, a paper towel or piece of newspaper should be placed inside the oven to absorb any moisture.
Conservation and restoration of ancient Greek pottery
Basic mechanical cleaning can remove dirt, dust, and grime. Cleaning solvents and water can also be used to remove dirt, varnish, wax, in-painting, or adhesives. Acids should be used with caution. Desalination is a cleaning method that removes as much soluble salt from the porous fired clay as possible. Fragments are soaked in highly purified water for multiple days. The water is changed regularly until salt levels are reduced.
Parts cleaning
For the activities described here the following terms are often found: metal cleaning, metal surface cleaning, component cleaning, degreasing, parts washing, parts cleaning. These are well established in technical language usage but they have their shortcomings. Metal cleaning can easily be mixed up with refinement of unpurified metals. Metal surface cleaning and metal cleaning do not consider the increasing usage of plastics and composite materials in this sector. The term component cleaning leaves out the cleaning of steel sections and sheets and finally degreasing only describes a part of the topic as in most cases also chips, fines, particles, salts etc. have to be removed.
Cast-iron cookware
Cast iron's ability to withstand and maintain very high cooking temperatures makes it a common choice for searing or frying, and its excellent heat retention makes it a good option for long-cooking strong-flavored stews or braised dishes. Because cast-iron skillets can develop a "non-stick" surface when cared for properly, they are excellent for frying potatoes or preparing stir-fries. Some cooks consider cast iron a good choice for egg dishes, while others feel the iron adds an off-flavor to eggs. Other uses of cast-iron pans include baking, for instance for making cornbread, cobblers and cakes.
Wok
Cast iron woks form a more stable carbonized layer of seasoning which makes it less prone to food sticking on the pan. While cast iron woks are superior to carbon steel woks in heat retention and uniform heat distribution, they respond slowly to heat adjustments and are slow to cool once taken off the fire. Because of this, food cooked in a cast iron wok must be promptly removed from the wok as soon as it is done to prevent overcooking. Chinese-style cast iron woks, although relatively light, are fragile and are prone to shattering if dropped or mishandled.
Acoustic cleaning
Acoustic cleaning began in the early 1970s with experiments using ship horns or air raid sirens. The first acoustic cleaners were made from cast iron. From 1990 onwards the technology became commercially viable and began to be used in dry processing, storage, transport, power generation and manufacturing industries. The latest technology uses 316 spun stainless steel to ensure optimum performance.
Architectural metals
Cast iron was a major 19th century building material of the Industrial Revolution. Although brittle, it is remarkably strong in compression. It was frequently used for structural purposes, such as columns, building fronts, domes and light courts. Decorative uses have included stairs, elevators, lintels, grilles, verandas, balconies, railings, fences, streetlights, and tombs. The Bradbury Building is an example of extensive decorative cast iron. Today, cast iron is used for plumbing fixtures and piping in new construction, and its structural and decorative use is used occasionally through historic preservation practices.
Clothes iron
In the industrialized world, these designs have been superseded by the electric iron, which uses resistive heating from an electric current. The hot plate, called the "sole plate", is made of aluminium or stainless steel polished to be as smooth as possible; it is sometimes coated with a low-friction heat-resistant plastic to reduce friction below that of the metal plate. The heating element is controlled by a thermostat that switches the current on and off to maintain the selected temperature. The invention of the resistively heated electric iron is credited to Henry W. Seeley of New York City in 1882. In the same year an iron heated by a carbon arc was introduced in France, but was too dangerous to be successful. The early electric irons had no easy way to control their temperature, and the first thermostatically controlled electric iron appeared in the 1920s. Later, steam was used to iron clothing. Credit for the invention of the steam iron goes to Thomas Sears. The first commercially available electric steam iron was introduced in 1926 by a New York drying and cleaning company, Eldec, but was not a commercial success. The patent for an electric steam iron and dampener was issued to Max Skolnik of Chicago in 1934. In 1938 Skolnik granted the Steam-O-Matic Corporation of New York the exclusive right to manufacture steam-electric irons. This was the first steam iron to achieve any degree of popularity, and led the way to more widespread use of the electric steam iron during the 1940s and 1950s.
Cast bullet
Although some bullet casting procedures can be accomplished with heating elements used for cooking; care must be taken to avoid contaminating food preparation areas and/or utensils with lead alloys. Most bullet casters prefer to use portable electric melting pots in areas with good ventilation. Molten metal can cause serious burns; and molten metal can be sprayed around the working area by violently expanding steam if it comes in contact with water from spilled drinks or other sources. Bullet casters should wear protective clothing including eye protection, and should carefully wash hands prior to eating, drinking, or smoking. Young children are especially vulnerable to lead poisoning and are unlikely to appreciate the danger of shiny molten metal and newly cast bullets. Bullet casting must be limited to times and locations when children are absent.
Particular risk comes from the oxides of lead and other metals present in lead alloys, as oxides are often more easily absorbed than the metallic forms. This means that the dross that is skimmed from the lead pot may pose a larger hazard than the metallic alloys.
Ironwork
Cast iron is produced in a furnace stoked with alternate layers of coking iron then poured into molds. After the iron cools off, the sand is cleaned off. The Chinese were the first to use cast iron from the 6th century AD using it as support for pagodas and other buildings.
William Kelly (inventor)
Before the technique of injecting air into molten iron was re-discovered by Kelly and by Bessemer, iron was available as cast iron, a strong but brittle metal made in a blast furnace by treating iron ore with coke derived from coal, and wrought iron, a more malleable and flexible metal made by heating iron ore in a low oxygen environment in a bloomery heated by charcoal and producing "blooms", which were 100 to 200 pound lumps of very low carbon iron mixed with slag. The blooms then had to be worked repeatedly by hammering with a helve hammer or later a steam hammer and folding it to work out the slag. This could in turn be converted to steel by heating it for prolonged periods sealed in stone boxes with charcoal, to add back carbon. The resulting steel could then be formed into larger shapes by heating it to welding temperature and hammering it together into a mass. Other laborious and expensive methods made small amounts of steel from special ores.
Drain cleaner
Galvanized iron is actually steel covered in a protective layer of zinc, but it was soon discovered that this zinc layer naturally corroded due to exposure to the atmosphere and rainwater, as well as cement, runoff, etc. Once corrosion occurred down to the base metal, plaques and rust would form, leading to sediment build-up that would gradually clog these drains. Thus, the first motivation for drain cleaners came to be.
Steel wool
Steel wool, also known as iron wool, wire wool, steel wire or wire sponge, is a bundle of very fine and flexible sharp-edged steel filaments. It was described as a new product in 1896. It is used as an abrasive in finishing and repair work for polishing wood or metal objects, cleaning household cookware, cleaning windows, and sanding surfaces.
Cookware and bakeware
Cast iron cookware is slow to heat, but once at temperature provides even heating. Cast iron can also withstand very high temperatures, making cast iron pans ideal for searing. Being a reactive material, cast iron can have chemical reactions with high acid foods such as wine or tomatoes. In addition, some foods (such as spinach) cooked on bare cast iron will turn black.
Cast-iron cookware
An American Dietetic Association study found that cast-iron cookware can leach significant amounts of dietary iron into food. The amounts of iron absorbed varied greatly depending on the food, its acidity, its water content, how long it was cooked, and how old the cookware is. The iron in spaghetti sauce increased 945 percent (from 0.61 mg/100g to 5.77 mg/100g), while other foods increased less dramatically; for example, the iron in cornbread increased 28 percent, from 0.67 to 0.86 mg/100g. Anemics, and those with iron deficiencies, may benefit from this effect, which was the basis for the development of the lucky iron fish, an iron ingot used during cooking to provide dietary iron to those with iron deficiency. People with hemochromatosis (iron overload, bronze disease) should avoid using cast-iron cookware because of the iron leaching effect into the food.
Cast saw
The patients' skin frequently comes into contact with the cast saw blade without cutting although it can cause lacerations when used over bony prominences. The design enables the saw to cut rigid materials such as plaster or fiberglass while soft tissues such as skin move back and forth with the blade, dissipating the shear forces, preventing injury. A general technique in the use of cast saw often involves a demonstration before actually cutting the cast.
Water softening
Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which "hardness ions"—mainly Ca and Mg—are exchanged for sodium ions. As described by NSF/ANSI Standard 44, ion-exchange devices reduce the hardness by replacing magnesium and calcium (Mg and Ca) with sodium or potassium ions (Na and K)."
Ion exchange resins are organic polymers containing anionic functional groups to which the divalent cations (Ca) bind more strongly than monovalent cations (Na). Inorganic materials called zeolites also exhibit ion-exchange properties. These minerals are widely used in laundry detergents. Resins are also available to remove the carbonate, bicarbonate, and sulfate ions that are absorbed and hydroxide ions that are released from the resin.
Stone slab
Clothes were washed manually, by rubbing and sometimes striking them against a hard surface with soap. The aim was to do penetrate the mix of water and soap between the fibres of the fabric to pull-out the dirt. The slabs to wash the clothes were slabs of natural stone chosen to present a fine and relatively flat surface. The small rounded irregularities could help of friction in the washing process.
Cast-iron cookware
Enameled cast iron is cast iron that has a vitreous enamel glaze applied to the surface. The fusion of the glaze with the cast iron prevents rusting, eliminates the need to season the metal, and allows more thorough cleaning. Enameled cast iron is excellent for slow cooking and drawing flavor from foods. Furthermore, pigments used in the enameling process can produce vibrant colors.
Water softening
Water softening is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water requires less soap for the same cleaning effort, as soap is not wasted mopping up calcium ions. Soft water also extends the lifetime of plumbing by reducing or eliminating scale build-up in pipes and fittings. Water softening is usually achieved using lime softening or ion-exchange resins but is increasingly being accomplished using nanofiltration or reverse osmosis membranes.
Cast iron
Cast iron and wrought iron can be produced unintentionally when smelting copper using iron ore as a flux.