I find it interesting that so many metalsmiths seem mystified by
alloying metals in their studios. I have been doing it for so many
years with positive results, I find it routine in its simplicity.
I have not found that the order the metals are put into the crucible
as important as having the correct amounts figured out. To make
sterling silver, with the traditional copper alloy, I just put them
together in a melting dish and melt them with a suitable torch,
stirring them with a carbon rod. A little borax flux is helpful.
Pour with the torch on full, into the ingot mold. Pretty basic stuff.
Alloying gold is pretty elementary, as well, and only the correct
proportions seem crucial for my work. I use ready made alloys from a
refiner here in Ca., and they all roll beautifully, draw easily, and
have great color. Just add pure gold and a big flame.
The math is easy: If you want to make 50 grams of sterling, muliply
50 by .925 (the amount of pure silver in sterling) and you get 46.25
grams. Weigh 46.25 grams of pure silver, and add copper to bring up
the total to 50.0 Don't fudge this! If you have 10 grams of pure
gold and want to make 18K yellow gold, divide the 10 grams by .75
(the amount of pure gold in 18K) and you get 13.33. Add 18K alloy to
your 10 grams of pure gold until you reach the 13.33, and you've got
13.33 gr. of 18K gold. Melt, add a bit of flux, stir with a carbon
rod, pour into your ingot mold with the flame on high.
Hope that helps.
Jay Whaley UCSD Craft Center