What is Pewter?Well, pewter is a metal alloy. That means it's a mixture of two or more metals. Tin is the major component of pewter at more than 90% and the rest is antimony, copper, and sometimes bismuth. Tin is the fourth most expensive metal in common use behind platinum, gold and silver. But don't be misled by the ranking. It's price is very far below silver. So why must pewter contain antimony and copper? Well, tin is a pretty soft metal and would easily deform even at normal temperatures, which makes it difficult to work with. So pewterers add antimony and copper to make it harder. Tin also melts at a rather low 232°C (450°F). Just to show you how low that melting point is, some plastics like polystyrene and ABS are actually processed at about this temperature. Anyhow, once alloyed with antimony and copper, the resulting pewter melts at a higher 250°C (482°F). Lead used to be the main hardener in pewter before it was replaced by antimony. Modern pewterers don't use it anymore (or very little of it) since it can cause lead poisoning. Long term exposure to lead, for example in using pewter plates and mugs, can result in brain disorder especially in children. The use of lead has been banned in just about anything except in areas where a replacement cannot be found. Are there differences between modern lead-free pewter and the poisonous (ok, that's a little harsh) old ones? Yes, there are. First of all, it's the 'look'. Newly-made pewter containing lead tends to have a bluish tint. This fades away as the pewter ages and it becomes a darker silvery-grey in color. That's due to tarnish (oxidation), and the main culprit is lead which gets oxidised pretty easily. Modern pewter tarnishes more slowly and is also more easily cleaned. Another feature of old pewter is the weight. Because lead has a much higher density than tin, lead-containing pewter is heavier. The more lead is added, the heavier it gets. For your comparison, lead has a density of 11.34 g/cm3 while tin's is only at 7.29 g/cm3. While looking for more pewter information, I came across 'Britannia metal'. This in fact IS the modern lead-free pewter as we know it. Britannia metal (or 'white metal') first emerged in England in the latter part of the 18th century. This alloy can be rolled into sheets which are later cut and shaped, even when they're cool. Now that you know what is pewter, why not find out a little about its history?
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