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removed via glass brush or clean rag .
Yellow gold physical properties and composition (one possible):
58-75% gold, 12-27% silver, 9-15% copper and some zinc
White Gold:
White gold is also a relatively simple metal to work with . There are two main types of
white golds – palladium-white gold and nickel-white gold .
Palladium – white gold composition (one possible):
58 .5% gold, 10% palladium, 28 .5% silver, 2 .5% (copper, nickel, zinc)
Nickel – white gold composition 14k (one possible):
58 .5% gold, 25 .8 % copper, 15 .3% nickel, 0 .4% zinc
Gold color can be changed with the following alloying (show alloy chart by composition and color)
Note the zinc content of white gold . High zinc content can lead to weld defects like porosity, etc .
as the zinc boils out of the weld joint . Please see the previous discussion on overcoming porosity .
In short, welding over the location with porosity again will help remove the porosity . A fresh, sharp
electrode will help with this process . Sometimes adding pure laser wire will also help in removing
porosity .
In general, gold welds easily . Here are some tips when working with gold:
1 . Typically a sharp electrode is preferred when welding gold .
2 . Gold can easily accept small or large weld spots
3 . It is often typical that gold will look black surrounding the weld location . This black layer is
easily removed with steam cleaning, clean rag, or a small glass brush .
4 . Gold can easily be added to almost any other metal .
5 . Very interesting welding combinations are possible .
Platinum (Pt)
Platinum (Pt) has a melting temperature that is similar to stainless steel, but a density that is 3
times higher . In addition, the specific heat of (Pt) is lower by a factor of 4 than stainless steel . This
means that it takes less energy to raise the temperature of (Pt) to its melting temperature . The
end result is that (Pt) is a little more difficult than stainless steel to weld but very similar in overall
behavior .
One important consideration when welding (Pt) is its high boiling temperature (3827 deg C)
relative to tungsten’s melting temperature (3410 deg C) . What this means: if the tungsten
electrode is contaminated with (Pt) metal the (Pt) metal may superheat and start to boil right on
the electrode . This boiling of the (Pt) will in turn melt the tungsten electrode causing it to lose its
sharp shape .
Palladium (Pd)
Palladium (Pd) is a white lustrous metal that is typically a much lower cost than platinum .
Palladium is also much lighter, having a density ½ that of platinum . It would seem that (Pd) is the
perfect metal . Unfortunately, (Pd) is generally difficult to work with and is somewhat difficult to
weld in a jewelry setting . This is mainly due to palladium cracking during the welding process .
