smelting report went lower than 18ct. need help please...

I was about to make a cuff with 18ct gold with a lot of scraps. I have asked to scrap dealers to test before the smelting. They confirmed they are mix of lower 18ct and higher 18ct.
Then I sent it to Assay office for Smelting service. and the result came out as 747.8 instead of 750.
:(|


I am seeking a replying to help below questions.

1. To get 18ct,
I presume I can melt this gold again with some pure gold. right?

By melting gold 3 times (smelting by Assay office, melting it with extra pure gold and lost wax casting), will the cuff soft and it might be a break? Will it affect the quality of the gold?

I presume the cuff has to be stronger than rings with a lot of movement.


2. If I go-ahead to add more pure gold, Can anyone please tell me how much pure gold I should add here?


3. Do you guys recommend to add a bit of pure gold when I work with a lot of known scraps to be safe for the future for the testing result?

Many many thanks to read this.

Gina

Cuffs can crack in use if the alloy is not right, so as you have the assay office result to show, why not sell it to a bullion dealer like Cookson and get new?

Most people add a little pure to re-cycled metal to be sure of the assay. In this case I think 5% would have been a generous amount, but I might be corrected. Dennis.

thanks to taking time to answering this.

Do you mean my 747.8 gold bar can have wrong alloy? or mixing 747.8 and 750 will crack the cuff?

Melting it again to mix more pure gold, will it weaken the gold?

I will probably have to sugget to my costumer to sell the gold. But she wants to keep the emotional value. so seeking the options to go back to her..

Can it be cracked this be mix to 14ct ?

You should be ok with 18ct it has lots of gold in it so will be more bendy (I cant spell malauble), For what you paying in assay and postage and such I think I would send the metal to be refined like Dennis said unless the metal has sentimental quality, then you know you are starting with an assay quality metal thats not had anything burnt out of it. If not you need to weight the metal you have, you know the gold content now from assay then work that back to find the amound of gold you need to add.

Thanks for this.
Assay office said this can be hallmarked as 14ct.

so I should be deciding it
Making 14ct hallmarked cuffs with this gold. Should be ok as Assay result is much higher than 14ct.
or melting down with pure gold to get 18ct. possibly bendy cuffs.
or selling this gold to pay for new gold, convincing my client
or I just decide without telling my costumer to sell the gold. feeling bad to do this. Can this happen to other jewellery?
Probably I should have known I had to add more pure gold to be a safe result.

Quote:

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Originally Posted by Gina777777

Then I sent it to Assay office for Smelting service. and the result came out as 747.8 instead of 750.
I presume I can melt this gold again with some pure gold. right?
If I go-ahead to add more pure gold, Can anyone please tell me how much pure gold I should add here?

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Add 8.8 milligram of pure gold to 1 gram of your 747.8 Gold.

For example if your gold is 10 grams, than add 88 milligram pure gold to make it exact 750.

Kindly note: Also make sure that the pure gold you are adding is 100 % pure, instead of 99.99, or 99.90, or 99.50.

All the best..

~JAS.