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Date Uploaded: May 20, 2004, 9:46 pm Last Edited: December 11, 2012, 5:57 am |
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Silver Chemistry
Article © MAIL User: Ragnarok
This is written because I have seen lots of people using silver for maille and I think everyone should know the basics:
Silver is available in different grades, described as parts of silver/thousand parts metal, for example sterling silver is denoted 925, meaning it contains 92.5% silver and 7.5% other metals. Technical grade silver can contain more than 99.9% silver, so it is the best source for pure silver one can find. The higher the purity, the better the chemical (corrosion, tarnish) resistance, but the lower the mechanical resistance. Usually, jewelry grade silver ranges from 850 to 950.
[silver is also sometimes listed as the decimal purity, as in 0.925 for sterling silver. -- ed.]
For small pieces, like maille jewelry, the choice is quite difficult, because if you don't solder it, the wire has to be both chemically and mechanically resistant. Grades between 850 and 900 work best for these purposes.
For soldering, go with pure silver, it helps cut down on firescale, among other things.
You can either buy wire, or a good jeweller can melt different items of silver (old coins, old jewelry, etc.) and turn it into wire of your desired thickness. Coins range in grade from 600 (poor quality, nasty looking, keep away from them) to 800 (common grade, quite nice) and even as high as 900, or even higher. Coin catalogues can tell you what grade a certain coin is. When you melt your own silver, you must exercise caution, because grades lower than 850 tend to be harder to work on and wire may have small defects. Another concern is lead solder, which, even in small amounts, can destroy your entire batch, making it brittle and impossible to turn into wire.
The best way to clean silver (I learned it from a jeweler) is to sink it in 10% sulfuric acid, which can be made by diluting one part battery acid in three parts of water (ALWAYS pour acid into water and not vice-versa). The object will have (after 15 minutes or so) a plain white colour, and it can be made into the common shiny silver by washing it with soap, using an old (thus softer) toothbrush. Be careful about putting clasps into the acid bath, because non-silver parts will also be attacked by the acid, resulting in interesting, yet unpleasant side-effects. Also, an interesting effect is obtained if you place a small piece of copper into the acid bath alongside the silver, because you could obtain a pale red-pink colour of the piece, which will wear off in time, but which would look nice while it lasts (try it on a small piece first).
It is best to use flat pliers or to cover the teeth of your regular pliers with duct-tape, because silver is more easily scratched than steel.
When subjected to high temperatures and cooled slowly, silver hardens. The heating process is tricky, because if you are using a flame, the thin wire can melt in one place and not get hot enough in others, so an oven of some sort should be used for maille items (which use wire diameters of around 1 mm).
I hope I haven't bored you to death and I also hope this has been of some practical use.
The Material
Silver is available in different grades, described as parts of silver/thousand parts metal, for example sterling silver is denoted 925, meaning it contains 92.5% silver and 7.5% other metals. Technical grade silver can contain more than 99.9% silver, so it is the best source for pure silver one can find. The higher the purity, the better the chemical (corrosion, tarnish) resistance, but the lower the mechanical resistance. Usually, jewelry grade silver ranges from 850 to 950.
[silver is also sometimes listed as the decimal purity, as in 0.925 for sterling silver. -- ed.]
Choosing the Right Material
For small pieces, like maille jewelry, the choice is quite difficult, because if you don't solder it, the wire has to be both chemically and mechanically resistant. Grades between 850 and 900 work best for these purposes.
For soldering, go with pure silver, it helps cut down on firescale, among other things.
Wire
You can either buy wire, or a good jeweller can melt different items of silver (old coins, old jewelry, etc.) and turn it into wire of your desired thickness. Coins range in grade from 600 (poor quality, nasty looking, keep away from them) to 800 (common grade, quite nice) and even as high as 900, or even higher. Coin catalogues can tell you what grade a certain coin is. When you melt your own silver, you must exercise caution, because grades lower than 850 tend to be harder to work on and wire may have small defects. Another concern is lead solder, which, even in small amounts, can destroy your entire batch, making it brittle and impossible to turn into wire.
Cleaning/Polishing
The best way to clean silver (I learned it from a jeweler) is to sink it in 10% sulfuric acid, which can be made by diluting one part battery acid in three parts of water (ALWAYS pour acid into water and not vice-versa). The object will have (after 15 minutes or so) a plain white colour, and it can be made into the common shiny silver by washing it with soap, using an old (thus softer) toothbrush. Be careful about putting clasps into the acid bath, because non-silver parts will also be attacked by the acid, resulting in interesting, yet unpleasant side-effects. Also, an interesting effect is obtained if you place a small piece of copper into the acid bath alongside the silver, because you could obtain a pale red-pink colour of the piece, which will wear off in time, but which would look nice while it lasts (try it on a small piece first).
Weaving
It is best to use flat pliers or to cover the teeth of your regular pliers with duct-tape, because silver is more easily scratched than steel.
Heat Treatments
When subjected to high temperatures and cooled slowly, silver hardens. The heating process is tricky, because if you are using a flame, the thin wire can melt in one place and not get hot enough in others, so an oven of some sort should be used for maille items (which use wire diameters of around 1 mm).
I hope I haven't bored you to death and I also hope this has been of some practical use.
Original URL: http://www.mailleartisans.org/articles/articledisplay.php?key=282
