18ct gold cracking

[BRJ]

I am making a ring from scrap 18ct gold which I have melted, cast and rolled. I am experiencing cracking along the length of the piece and annealing is not helping. Result - stress and frustration!

Is this due to quenching after casting?

I suspect that this might be occurring due to the scrap not being of a good quality (although I did test and is definitely 18ct). Any suggestions of what I could try to rectify this?

Thank you for any help offered.

[Dennis]

You can try to rectify it by adding 5-10% of 24ct gold, but my experience is that recovered scrap gold does not work well and will flake or crack when rolled. personally I would sell it and buy new. Dennis.

[Myosotis]

I used to do a lot of this - very popular with customers. Recovered scrap gold worked well usually but sometimes you'd get a bad batch that would crack. Try remelting with some higher carat and don't pour immediately when it starts to spin, also if its a small amount try cuttlefish or delft instead rather than an ingot mold.

[Tabby66]

I'm with Dennis here. I'm afraid that a melt-up is never as good as fresh metal, that said, usually the higher carat of gold the better the result of the resulting metal......was there much solder in it?? That can cause brittleness, also air cool rather than quenching and as myositis suggests, make sure the gold is rolling well before pouring/taking the heat away and add a little higher carat gold to the mix to improve the outcome!!

[BRJ]

Thanks for your help. I have successfully made the ring with another piece of the customer's own 18ct (cracked piece was of peru so perhaps a dodgy alloy, second piece was italian and workied fine). I will add the peruvian gold to other mix, to make bangles for customer and will take your advice about quenching. Failing that I will try to refine. Unfortunately, it appears that the majority of my business comes from remakes these days.

[Dennis]

Glad you worked it out. Dennis.