Now _my_ problem-- I live fusing 24k gold onto my fused
silver. It works just fine, except that the silver tends to melt
over the surface of the gold and hide it. This is particularly a
problem with granules.
Noel, this sounds as if it’s a problem with the bonding. Ask
yourself if you have enough copper coating on the gold granules to
lower the fusing temperature? Silver melts at a lower temperature
than gold, so it’s really easy to get your granules coated with
silver. Keep your torch concentrated more towards the silver, so the
silver is only attaching to the bottom of the gold granules, rather
than getting the gold granules hot enough the silver runs up them and
coats them. Are you using a liquid flux and is it thinned out with
enough water to keep it from “working” too much, thus lifting the
granules and preventing their fusion before the flux becomes molten?
Even after I clean them off (no longer so round), they don't
look like 24k any more.
Several things can be possibly tied into this and your fusion
problem. The first is the gold itself. Quite a few manufacturers will
use just a bit of zinc (it vaporizes) even in pure gold or silver,
because, so I’ve been told, it makes the wire easier to draw and
sheet easier to roll. This same source also said it causes a problem
in fusing, with the trace amounts of zinc causing microscopic pitting
and preventing the fusion. So you might check with your manufacturer,
and tell them your reason for the inquiry. A reliable source in the
U.S. is Hoover and Strong.
Another problem is that 24 kt. gold is very soft and can be easily
distorted with just the slightest pressure. You may want to change to
22 kt., as the difference in color is hardly perceptible, but it has
the ability to withstand a little more. I’ve also found the 3M
bristle disks in the 6 and 1 micron size are great for putting on a
very nice polish without flatspotting. A quick touch with rouge on a
loose muslin wheel completes the final polish.
I hope this gives you some ideas to pursue, and changes your
frustration to pleasure in achieving what you envision.