Ceramics and Pottery

Latex paint from tileI just finished painting my own bathroom. Just use a putty knife on a slight tilt and carefully push on the paint spots (don't rush this job), then wipe clean. As for the latex paint on the grout, be sure you have waited a couple of weeks, wet it down, and then use "Scotch Brite" pads to gently go over the grout. Do not push on the pad too much. Latex, as you know, can be taken off with water. I use warm, soapy water to do this.

More advice from Wiki s Contributors:

• Keeping it wet and warm is a big plus, especially if it is fairly recent. Try to use a scraper that is plastic if possible. Sometimes an abrasive handcleaner and a stiff plastic bristle brush will do the trick.

• This site has professional tile guys that have helped me in other areas: http://www.johnbridge.com

There are products on the market that were originally created to specifically meet this type of need.Today they are used for a wide variety of cleaning and removing purposes however they still do a great job for removing dried dripped or spilled latex paint from finished,painted or glazed surfaces.The two most well-known brands are "Oops" and "Goof-Off".These products are sold at most hardware or home improvement stores and are also sometimes found in the cleaning aisles of grocery stores and department stores.

If your spills are on vinyl flooring,carpet or other similar surfaces be sure to read the label carefully as these products can sometimes damage those types of materials.If you feel you have questions shop for these products at businesses that offer knowledgeable saleshelp to assist you.

There is a wide variety of modelling clays: Mineral clays, are refined forms of the clay you may find in the ground, and are dense over two kg/l

Polymer clays are much lighter, about 1 kg/l

and paper based clays can be very light, depending on their dryness.

If you have an actual sample the best thing to do would be to measure it.

allows water and other volatile components of the clay to escape freely. The coarser particles in the clay also acted to restrain shrinkage within the bodies of the wares during cooling which was carried out slowly to reduce the risk of thermal stress and cracking. In the main, early bonfire-fired wares were made with rounded bottoms to avoid sharp angles that might be susceptible to cracking. The earliest intentionally-constructed kilns were pit-kilns or trench-kilns--holes dug in the ground and covered with fuel. Holes in the ground provided insulation and resulted in better control over firing.[citation needed]

The earliest-known ceramic objects are Gravettian figurines such as those discovered at Dolni Vestonice in the modern-day Czech Republic. The Venus of Dolní Věstonice (Věstonická Venuše in Czech) is a Venus figurine, a statuette of a nude female figure dated to 29,000-25,000 BCE (Gravettian industry).[24] The earliest pottery vessels found include those excavated from the Yuchanyan Cave in southern China, dated from 16,000 BCE[25], and those found in the Amur River basin in the Russian Far East, dated from 14,000 BCE [26][27].

Other earlier pottery vessels include those made by the Incipient Jōmon people of Japan from around 10,500 BCE have also been found.[28][29] The term "Jōmon" means "cord-marked" in Japanese. This refers to the markings made on the vessels and figures using sticks with cords during their production. It appears that pottery was independently developed in North Africa during the 10,000 BCE[30] and in South Americaduring the 10,000 BCE[31] In several cultures, the earliest vessels were made either by hand-shaping or by rolling the clay into a thin round cord which was then coiled round on itself to form the vessel. The earliest history of pottery production in the Near East can be divided into four periods, namely: the Hassuna period (5,000-4,500 BCE), the Halaf period (4,500-4,000 BCE), the Ubaid period (4,000-3,000 BCE), and the Uruk period (3,500-2,000 BCE).

The invention of the potter's wheel in Mesopotamia sometime between 6,000 and 4,000 BCE (Ubaid period) revolutionized pottery production. Specialized potters were then able to meet the expanding needs of the world's first cities. Pottery was in use in ancient India during the Mehrgarh Period II (5,500-4,800 BCE) and Merhgarh Period III (4,800-3,500 BCE), known as the ceramic Neolithic and chalcolithic. Pottery, including items known as the ed-Dur vessels, originated in regions of the Indus valley and has been found in a number of sites in the Indus valley civilization.[32][33]

In the Mediterranean, during the Greek Dark Ages (1,100-800 BCE), amphoras and other pottery were decorated with geometric designs such as squares, circles and lines. The period between 1,500-300 BCE in ancient Korea is known as the Mumun Pottery Period.[34] In the Chalcolithic period in Mesopotamia,Halafian pottery achieved a level of technical competence and sophistication, not seen until the later developments of Greek pottery with Corinthian and Attic ware.[citation needed] The distinctive Red Samian ware of the Early Roman Empire was copied by regional potters throughout the Empire.

Archaeology

Pottery found at Çatal Höyük - sixth millennium BC

For archaeologists, anthropologists and historians the study of pottery can help to provide an insight into past cultures. Pottery is durable, and fragments, at least, often survive long after artifacts made from less-durable materials have decayed past recognition. Combined with other evidence, the study of pottery artifacts is helpful in the development of theories on the organisation, economic condition and the cultural development of the societies that produced or acquired pottery. The study of pottery may also allow inferences to be drawn about a culture's daily life, religion, social relationships, attitudes towards neighbors, attitudes to their own world and even the way the culture understood the universe.

Chronologies based on pottery are often essential for dating non-literate cultures and are often of help in the dating of historic cultures as well. Trace-element analysis, mostly by neutron activation, allows the sources of clay to be accurately identified and the thermoluminescence test can be used to provide an estimate of the date of last firing. Examining fired pottery shards from prehistory, scientists learned that during high-temperature firing, iron materials in clay record the exact state of Earth's magnetic field at that exact moment.

Environmental issues in productionAlthough many of the environmental effects of pottery production have existed for millennia, some of these have been amplified with modern technology and scales of production. The principal factors for consideration fall into two categories: (a) effects on workers, and (b) effects on the general environment. Within the effects on workers, chief impacts are indoor air quality, sound levels and possible over-illumination. Regarding the general environment, factors of interest are fuel consumption, off-site water pollution, air pollution and disposal of hazardous materials.

Historically, "plumbism" (lead poisoning) was a significant health concern to those glazing pottery. This was recognised at least as early as the nineteenth century, and the first legislation in the United Kingdom to limit pottery workers' exposure was introduced in 1899.[35] While the risk to those working in ceramics is now much reduced, it can still not be ignored. With respect to indoor air quality, workers can be exposed to fine particulate matter, carbon monoxide and certain heavy metals. The greatest health risk is the potential to develop silicosis from the long-term exposure to crystalline silica. Proper ventilation can reduce the risks, and the first legislation in the United Kingdom to govern ventilation was introduced in 1899.[35] Another, more recent, study at Laney College, Oakland, California suggests that all these factors can be controlled in a well-designed workshop environment.[36]

The use of energy and pollutants in the production of ceramics is a growing concern. Electric firing is arguably more environmentally friendly than combustion firing although the source of the electricity varies in environmental impact.[citation needed]

Other usagesDue to the large number of pottery factories or, colloquially, "Pot Banks", the English city of Stoke-on-Trent, one of the first industrial cities of the modern era where, as early as 1785, two hundred pottery manufacturers employed 20,000 workers, is often called "The Potteries".[37]For the same reason, the largest football club in the city, is known as "The Potters".[38]