Melting scrap gold

[Jimbo]

Hi, I am looking for some guidance regarding melting scrap gold for re-use in a ring that I am constructing.

I have about 22g of 9ct yellow gold that I have melted down and will be rolling the ingots down into the various thickness's required for the ring construction. Will there be any issue in terms of assay quality of the final piece if I melt and re-melt the gold to get the various components. Should I be adding casting grain to the melt at any point to pull the gold back to 9ct assay quality.

The gold that I started with was all provided by my client and hallmarked as 9ct. Part of the design introduces a new component of white gold, the finished product therefore will have to be hall marked - hence my concern regarding maintainng assay quality of the yellow gold.

Kind Regards Jim

[Dennis]

To be sure of passing the assay it is customary to add a proportion of fine metal to the melt. I don't use recycled metal, so I'm not sure how much, but in the case of 9ct, about 5% is my guess. Someone will be along shortly with a more authoritative reply. Dennis.

[enigma]

I do melt my scrap gold and silver down quite a lot without adding casting grain in and have not had any problem with having it assayed.
As long as no other metal gets mixed in I don't see why there should be a problem?

[Unhindered]

if I know im having it hallmarked I add a tiny bit of 18ct to a 9ct melt just incase, but it may not be needed its just habit from a previous job! They weren't exactly the best goldsmiths though so it could be wrong!

[Jimbo]

Thank you all for your responses. Sounds like I should add a small amount of casting grain to be on the safe side. Some of the scrap only had '375' marks and not full hall marks, so will err on the side of caution..

Thanks again.

[TeeDee]

I do melt my scrap gold and silver down quite a lot without adding casting grain in and have not had any problem with having it assayed.
As long as no other metal gets mixed in I don't see why there should be a problem?

Sarah,
Do you ever have a problem with hard solder? I did a melt of 9ct mixed scrap and when I went to solder with hard, I managed to get the parent metal to slump. It seemed that the resultant alloy was very close to the melting range of the hard solder. (See pic) Had to re melt and use medium solder.

Also the alloy was streaky as though the copper had seperated. Looked quite nice though but I wonder how it would stand assay
Tim

[Kiri]

Hi!
You clearly have knowledge in this area I was wondering if I could pick your brain please?
I have two yellow gold rings to melt down for a customer to make their wedding bands out of. They are aware that I haven't done this before but I want to get it right! They want me to turn it into rose gold. Would I just add some red gold grain to the mix to achieve this or can I not mix them up like this?
Also am I meant to prepare my scorifier with borax powder and heat first? I haven't used it yet!
I really appreciate your time and any advice that you can give me.
Thanks
Kiri :-)

[Dennis]

You are not getting any answers Kiri, so here are some thoughts to bring you to the top of the page again.

You have not said what carat your rings to be melted are. It would be easiest if your addition were the same carat. You can add casting grains of red gold, but it would take a substantial addition to make a difference to the colour, which could be costly.

You would probably have to guess how much, given that you have to allow for the sprues too, and then let the customer see a polished surface, to approve it before going further. Dennis.