|A Saxon Spearhead from Batheaston Bypass, still in one piece and stable.|
|Pewter patera after conservation|
Learning about different types of metals, surface treatments and the process of corrosion is very useful, if only to highlight how much could go wrong with metal objects! A major problem is corrosion, caused when a metal object combines or reacts with other elements to form an undesirable compound, such as tarnish or rust. Corrosion is different from patination, which is generally more benign and will slow and stop without intervention – this occurrence can be seen on copper clad roofs as a blue green compound known as verdigris.
|Statue of Liberty – the blue green colour is a result of natural patination|
If you’re looking to find out more about the scientific side to archaeology, National Science and Engineering Week at the Roman Baths, 9th-18th March 2012, is definitely a date for your diary!