question: Why do pots corrode when you use them on an inductive cooktop? Why does it generally only occur the first time?
comment: I use an induction cooktop every day and haven't ever seen or heard of this. Can you explain further?
passages: Cookware in which copper is the main structural element (as opposed to copper clad, copper sandwiched or copper colored) is sometimes manufactured without a lining when intended to be used for any of a number of specific culinary tasks, such as preparing preserves or meringues. Otherwise, copper cookware is lined with a non-reactive metal to prevent contact between acidic foods and the structural copper element of the cookware.
   Typical firing probably took place at a temperature of 850 to 975 degrees Celsius. With constant firing of the kiln, such temperatures were reached after about 8 to 9 hours. During this process, the vessels in the oven initially lost whatever moisture remained in them. At a temperature of 500 °C, after 6 or 7 hours, true firing of the now red-hot vessels began. With a constant supply of oxygen and a still increasing temperature, the iron-rich shiny slip oxides and turned red, along with the rest of the vessel. During this process, the iron content is transformed into deep red hematite (FeO).
   Lining copper pots and pans prevents copper from contact with acidic foods. The most popular lining types are tin, stainless steel, nickel and silver.
   Crevices can develop a local chemistry which is very different from that of the bulk fluid. For example, in boilers, concentration of non-volatile impurities may occur in crevices near heat-transfer surfaces because of the continuous water vaporization. "Concentration factors" of many millions are not uncommon for common water impurities like sodium, sulfate or chloride. The concentration process is often referred to as "hideout" (HO), whereas the opposite process, whereby the concentrations tend to even out (e.g., during shutdown) is called "hideout return" (HOR). In a neutral pH solution, the pH inside the crevice can drop to 2, a highly acidic condition that accelerates the corrosion of most metals and alloys. 
   Pottery is typically decorated with raised dots made by a carved roulette, which may cover most of the body of the pot. Often the dots are combined with grooved lines, and may make a net-like pattern over the body of the pot. Both the figurines and the pottery were baked at low temperature, and are therefore fragile.
  
  Section::::Iron working.
   When todorokite was first discovered, in 1934, modern methods of mineral analysis were not available, and one of the standard techniques was to use a blowpipe to heat a small sample of the mineral, and observe its behavior. Todorokite was tested in this way, and it was noted that under the blowpipe it turned brown and lost its metallic luster, but did not fuse.
  
  X-ray diffraction lines at 9.5 to 9.8 Å and 4.8 to 4.9 Å are characteristic. This is also true of buserite NaMnO·21HO.
  
  Section::::Type locality.
   Section::::Copper.
  
  Copper's carbonate form (CuCO) is commonly used to produce greens, turquoise, and copper reds. If need be, copper oxide (CuO) can be substituted but has a larger particle size and glazes should be adjusted to generally half the amount called for. In barium based glazes greenish blues often result from copper. Alkaline feldspar glazes with copper fired in reduction atmospheres will often yield ox blood or copper red glazes discovered by the Chinese. When fired above cone 8 copper can become unstable and will often fume off of a glaze in vapor form. 
  
  Section::::References.
   Section::::Chrome.
  
  "Chrome is a rather versatile and fickle colorant," (Chappell). Chrome oxide (CrO) is commonly used for achieving greens. However, in the presence of zinc, chrome can produce brown. Glazes with tin oxide present will often blush to pink if fumed with chrome or if chrome is present in the glaze with the tin, often intense pinks occur. If fired above cone 6, chrome will fume and become a gas in the kiln. Common saturation percentages for chrome at low saturation range from (.25 to .5%) and at higher percentages from (1 to 2%). Chrome is a refractory. 
   BULLET::::14. The magnesium-alloy panels, painted with good grades of aluminum-pigmented varnishes, were in excellent condition after 2 years of weather exposure, except for slight failures at the edges of and adjacent to those rivet heads from which the paints were off. Paint failures in the tidewater tests became advanced during the second year on three-coat paint schedules. Schedules involving two coats of P27 type (zinc-chromate pigments) primers and two additional coats of aluminum-pigmented varnishes of good grade usually remained in good condition, especially when the second coat of primer was also aluminum pigmented. Primers of the P23 type (iron-oxide pigments) reacted to accelerate attack on the mangesium alloys, after coating failures had occurred.
   Magnesium plates are very dangerous in molten lead, because this metal can easily burn and will ignite in this way the metal in the pot.
  
  Section::::Contamination of type metals.:Iron.
  
  Iron is hardly dissolved into type metal, although the molten metal is always in contact with the cast iron surface of the melting pot.
  
  Section::::Historic references to type metals.
  
  Joseph Moxons', in his "Mechanick Exercises", mentions a mix of equal amounts of "antimony" and iron nails.
   Fractures caused by thermal shock called "dunting" occur during the firing process and are witnessed in the bisqued ware stage. Dunting is a problem that commonly occurs during the cooling process of the firing cycle. Latent or dormant cracks which went unnoticed in greenware may appear in bisqued ware after firing.
   Metal pots are made from a narrow range of metals because pots and pans need to conduct heat well, but also need to be chemically unreactive so that they do not alter the flavor of the food. Most materials that are conductive enough to heat evenly are too reactive to use in food preparation. In some cases (copper pots, for example), a pot may be made out of a more reactive metal, and then tinned or clad with another.
  
  Section::::Cookware materials.:Metal.:Aluminium.
   Burnishing (pottery)
  
  Burnishing is a form of pottery treatment in which the surface of the pot is polished, using a hard smooth surface such as a wooden or bone spatula, smooth stones, plastic, or even glass bulbs, while it still is in a leathery 'green' state, i.e., before firing. After firing, the surface is extremely shiny. Often the whole outer surface of the pot is thus decorated, but in certain ceramic traditions there is 'pattern burnishing' where the outside and, in the case of open bowls, the inside, are decorated with burnished patterns in which some areas are left matte.
   As said, a pottery sometimes has a different actual use than intended use. This is the reason why when archaeologists study the function of a pottery, they tend to focus on how the tool was actually used. They do this by studying the alterations that the pottery has. These alterations, accretion and attrition, are commonly the abrasions and scratches on the vessel. In Skibo's study of Kalinga potteries functions, he relied on three main tests, namely (1) dissolved residue, (2) surface attrition and (3) carbon deposition. 
   Using modern metal bonding techniques, such as cladding, copper is frequently incorporated into cookware constructed of primarily dissimilar metal, such as stainless steel, often as an enclosed diffusion layer (see "coated and composite cookware" below).
  
  Section::::Cookware materials.:Metal.:Cast iron.
   In terms of surface interactions, chromium oxide is polar. The oxygen atoms on the surface have a permanent dipole moment, and are therefore hydrophilic. This means that water will wet it, but oils or other lipids will not.
  
  Section::::Materials in cooking.:Cast iron.
   Fracture in greenware resulting in stresses during the making. To avoid cracks in greenware uniformity should be maintained in the thickness of the pot, the drying of the greenware, as well as consistency of the clay body itself. Cracks can result in uneven drying from thinner to thicker spots within the pot. A lack of compression in the bottom while throwing results in a commonly seen "s" crack on the underneath of the pot.
   Anodized aluminium has had the naturally occurring layer of aluminium oxide thickened by an electrolytic process to create a surface that is hard and non-reactive. It is used for sauté pans, stockpots, roasters, and Dutch ovens.
  
  Uncoated and un-anodized aluminium can react with acidic foods to change the taste of the food. Sauces containing egg yolks, or vegetables such as asparagus or artichokes may cause oxidation of non-anodized aluminium.
   As said, a pottery sometimes has a different actual use than intended use. This is the reason why when archaeologists study the function of a pottery, they tend to focus on how the tool was actually used. They do this by studying the alterations that the pottery has. These alterations, accretion and attrition, are commonly the abrasions and scratches on the vessel. In Skibo's study of Kalinga potteries functions, he relied on three main tests, namely (1) dissolved residue, (2) surface attrition and (3) carbon deposition. 
   The reaction then repeats from equation (3). It is the presence of two different white and green salts that lead to the fuzzy green appearance.
  
  Section::::Treatment and prevention.
  
  Initial treatment can involve placing the object in a desiccating environment. Deprived of water, the reaction cannot continue. However, re-exposure of the object to even atmospheric water can restart the process. The following are examples of treatments used in the past, though some continue to present day. Bronze disease, along with similar visual conditions caused by other moieties, remains an active area of research within object conservation. 
  
  Section::::Treatment and prevention.:Surface treatment.
   Norstad pots were most noted by their distinctive glazes, often with markings in a Japanese style Sumi-e brushwork. In earlier pieces relief features or decorated carvings were added to the pots.
   Some metals, such as untreated aluminium, require a primer; others may not. A primer designed for metal is still highly recommended if a part is to be exposed to moisture. Once water seeps through to the bare metal, oxidation will begin (plain steel will simply rust). Metal primers might contain additional materials to protect against corrosion, such as sacrificial zinc. 
   Section::::Red Iron.
   Other processes that can occur while the pot is in the leather-hard state include both glazes and slips. Slips can form when water is added to clay at a level higher than the rate of plasticity. However, one must be careful when working with slips as it is a fine, silica based material that could be hazardous if inhaled. This can add a layered effect onto the pottery itself. Glazes are a glassy coating that can be applied like a paint to a vessel when it is either leather-hard or briefly fired. When glazes are applied in the leather-hard stage, they tend to run a lesser risk of cracking the pot when they are fired. However, there are still instances when the glaze will crack no matter what is done to prevent it due to any number of changes that could happen during a firing.. When the pots have been fired before the glazes are put on, they are referred to as biscuits. It is important not to confuse leather-hard with biscuit. Despite the fact that it may seem as though the two are similar, only a leather-hard vessel can return to a plastic state. In fact, a biscuit vessel, while looking similar to the leather-hard vessel, has fired to around 1652-2012°F, and is therefore a fired ceramic, not unfired clay. Another process that can occur while a vessel is in the leather-hard state is to fettle the vessel. This refers to what happens when trimming is done to the edges or casting marks that are on the pot from the initial molding of the vessel, allowing it to gain a smoother texture. 
   Between the leather-hard pot and the fired pot is one more phase: the application of the slip or glaze. Even when the pots are leather-hard, there is a danger of their cracking during firing due to rapid loss of water and shrinking. All pottery to be fired is coated with a layer of slurry that impedes water loss. The quality and color of the baked surface depends on the substance applied. There are many traditional substances used for the purpose. If the result is a surface of glossy texture the substance used is called a slip. If the substance is such that it causes a glassy surface, it is called a glaze.
  
presuppositions: Pots corrode when you use them on an inductive cooktop for the first time. Pots corrode when used on an inductive cooktop.
corrections: Pots do not corrode when you use them on an inductive cooktop for the first time. I have never heard of or seen pots corrode when using them on an induction cooktop.
raw_presuppositions: Pots corrode when you use them on an inductive cooktop for the first time. Pots corrode when used on an inductive cooktop.
raw_corrections: Pots do not corrode when you use them on an inductive cooktop for the first time. I have never heard of or seen pots corrode when using them on an induction cooktop.