Sustainability and manufacturing
The metal pewter has been used since ancient times and is extracted from the mineral cassiterite. At Humstorp Metallverkstad in Västergötland they are constantly working on choosing the most environmentally friendly alternatives when purchasing. Throughout the manufacturing process, waste is minimised and whatever metal scrap remains is sent to recycling. Excess pewter can be melted down and used once again. In addition, a separate solar power facility provides approximately 40% of the workshop’s electricity consumption.
This is how Anna Petrus’ pewter lion is manufactured
It takes approximately 12 – 15 hours to manufacture Anna Petrus’ classic pewter lion at the workshop in Västergötland. The first step in the process is to start the crucible. The pewter is melted at 263°, and it takes approximately one hour before it is sufficiently warm to be cast into the moulds.
The lion comprises six different parts which are cast individually, a factor which demands enormous precision and craftsmanship. The slightest incorrect calculation can result in a casting being rejected and melted anew, and therefore it is of the greatest importance that the various moulds are of the right temperature, that they are angled correctly and that the pewter is cast into the moulds at the right speed.
Once the moulds are ready, each piece must be ground and filed. After that, it’s time for the most critical moment in the process, namely soldering the six different parts into a lion.
In many other cases, when soldering, an alloy can be used that melts earlier than the mould, which makes the process simpler. When manufacturing the pewter lion, however, the same pewter alloy is used as in the moulding, with the consequence that the pewter that is added melts simultaneously with the pewter in the different parts of the lion. This makes the work more difficult, but avoids having small colour differences upon assembly.
Once the soldering is completed and the pewter lion is assembled, it’s time to grind down the soldering and create the lion’s deeper contours by hand. After that, it’s polished in order to obtain its fine lustre. At this stage, an inspection is also made as to whether any part of the lion must be repaired or reworked. The least impurity in the pewter means that the lion must be soldered, ground and polished until the correct final result is achieved.
Sustainability in focus
Read more about Svenskt Tenn's Sustainability Philosophy below.