I am used to rolling sterling silver through my rolling mill and usually make 1/4 to 1/2 turn passes annealing maybe three or four times to get a 6.4 mm ingot to 4 mm by 2 mm wire. With gold I notice it forms cracks annealing this frequency.
There is nothing wrong with the alloy chemically. My copper was .999 as was my silver and my gold bullion was .9999. I allowed some 18K with 75% ahold 15% copper and 10% silver and some 14K with 58.5% gold 25% copper and 16.5% Silver and both cracked much more than I am used to. I ended up just annealing every three or four passes making an 1/8 to a 1/4 turn and it still cracked but not as much. Rolling my usual way caused to 18K to form deep cracks all across its surface and it was unusable. I had to re-pour it. I was more careful with the 14K but it still cracked.
I am not experienced with gold so I am not sure if this is normal. For goldsmiths who work with gold everyday, please tell me your experiences rolling ingots and what you do to prevent cracks!
Thanks for any help,