Assay of re-melted scrap silver with solder contamination

[altjewellery]

Hi Folks - 1st post for me here - I have been searching for a metalwork focused jewellers' forum & this seems one of the best. I buy most supplies from Cookson's too so I guess it makes sense

Anyhow......

I wonder if anyone has any experience of, or advice to offer on the assay of recycled sterling from scrap with solder joints ?

I am building up a nice quantity of scrap bits & pieces, much of which has solder joints. Weighing it the other day got me thinking of investing in a rolling mill so I can re-use some of it, potentially draw some wire from it, etc.

However I'm concerned that any stuff needing hallmarking may fail if it falls below 925 due to the lower silver content in the solder.

Is there any kind of tolerance applied to the silver content of sterling in the assay process ? I guess I could just chuck a bit of 'fine' grain into the melt to bring the silver content up a bit, in which case it would likely end up over 925 but less than 999. Would that still qualify for assay as sterling ? I'm guessing that anything over 925 but less than 999 would do so ?

I re-melt a fair bit of scrap already but just 'clean' stuff or sprues. I generally cut it with the same weight of grain in an effort to reduce porosity. I guess if I cut soldered scrap with a mix of sterling & fine grain I would take it over 925.

I guess I could have the ingots assayed before use to be sure, provided there is no requirement for the starling to be exactly 925.

Hope my rambling makes some sort of sense.

Thanks very much

Nick (altjewellery)

[medusa]

no idea, but I like you hammered bracelet!

(yes. I'm nosy)

[Goldsmith]

Hi Nick, I recently took a box of silver scrap to the London Assay Office, for a fee of around £35 they will melt and assay, takes a few days but when you collect it you have documentation that any bullion buyer will accept as a true value of the scrap you are selling. If you melt it up yourself they will still assay it and give you a paper telling you what assay it reached. Then find yourself a bullion dealer who pays a fair price, which will depend on the assay.
James

[altjewellery]

Hi Medusa - thanks 4 that - good bit of detective work ! I'm updating the website just now (it's been lying unloved for months) that's why I didn't say 'hello' on the Introduce Yourself forum & tell folk about it - it's so outdated. Funny, the hammered bracelet was one of the things I was considering melting down !

Cheers

Nick

[altjewellery]

Hi James - thanks for your reply.

I was thinking more along the lines of melting it & either rolling sheet or pulling some wire from it to use on new pieces. My concern is that if I do this it would assay as less than 925 meaning I couldn't have it hallmarked as sterling. I guess I could restrict the use of it to very light pieces not needing hallmark, but I wouldn't feel comfortable selling it as sterling unless I could, hand on heart, say it was 925 or over.

My theory is that if I melt it myself for new pieces I save on having to buy new sheet & wire etc, and I don't lose out to some extent selling it at scrap value.

I take your point though - probably better to have the ingot assayed 1st (or even just have them melt it too) & take it from there. At least then I would know what grade metal I was working with.

To be honest I don't have 'that' much, I'm just looking for justification for shelling out on a new mill.

Cheers

Nick

[Goldsmith]

I understand what you are thinking, A few weeks ago I got three kilos of silver scrap and lemel melted and assayed and got £0.49 per gram for it. This gave me approx £1400 after costs to buy new metals with. I charge by the hour so it works out cheaper for me to buy new sheet and wires rather than spending time rolling sheet and drawing wires, my mills and wire draw bench are rarely used these days.
James

[altjewellery]

You're right as regards the cost of time for all the messing about, certainly for the volumes you're talking about James. I am much smaller scale (part time / hobby level) and have maybe 100g of bits. I am thinking of buying a cheapish mill so as I accumulate these bits of scrap, and need a bit of wire of a dia. I don't have in stock I can pull a bit, maybe pull a fair bit down to 2mm or so for stock 1st to save me melting each time. I don't want to go to all that bother if when I send it for hallmarking it fails to make 925 due to solder contamination though.

If I had three kilos I'd be off to the Bahamas !

Nick

[altjewellery]

Just looked at some of your stuff on your profile by the way James - it's awesome.

[Goldsmith]

I just added a couple of photos to my album, of a gold and silver table centre that I made a few years back,when I made this piece, I used 4 kilos of silver and over 1 kilo of 18ct gold, this is just to give you some idea of the amount of sheet metals that I have to buy.
Glad you like my work!
James