An Introduction to Alloys, Part 1
If you are like me, you missed the ‘know your alloys’ lecture that one day in metallurgy class. Well, you’ve got a second chance as I’m willing to share all the knowledge I have gained about bronze, brass, polishing, refinishing and the rest while working at Progressive Bronze.
Most of the products we deal at Progressive Bronze with are made out of one of four metal combinations, or alloys – bronze (of course), brass, aluminum, and white metal. Now these are the actual structural bits – plating in several different metals is available, but we will discuss that another time. Bronze and brass get used as decorative metals quite often, when an attractive color and luster is desired but more precious metals like gold are too expensive, or too soft for the application.
Bronze is primarily a combination of copper and tin and holds great historical importance. You may have heard of the Bronze Age, the period of human history which spans the years 3600 BC – 300 BC and represents the first time any metal was smelted to produce tools. The desire for this new alloy also led to another important development: tin used in Bronze can only be found in certain select areas around Europe. This necessitated the strengthening of some established trade routes, and the creation of some new ones. The British Isles, Cornwall particularly, became an important source.
Image courtesy of vintagedept
Bronze is both harder and more corrosion resistant than straight copper or even iron, though iron was easier to find and produce. That availability and simplicity is why it succeeded bronze as the tool metal of choice in the last millennium BC, though Roman officers would still carry bronze swords, while their troops carried iron.
Bronze continues to be important today, as it is used for several industrial applications, like ship propellers and bearings, as well as decorative hardware, statues, and 3rd place medals at international sporting events. Here at progressive Bronze, we continue to manufacture new pieces from bronze, primarily for churches, via out Excelsis line.
In its polished form, bronze takes on a reddish hue, and when the outer layers oxidize it forms a dark patina which protects it from additional oxidation/corrosion. At Progressive Bronze, we find that people prefer the polished look to last, so we lacquer all of our new and refinished items to keep oxygen out.
That will do it for our bronze primer. We’ll be doing posts on the other metals in the coming weeks, so check back from time to time, or follow us on Twitter to get all the updates!
And of course if you ever have any questions, or projects you’d like us to take a look at, send us an email.