Remodelling using gold from existing setting

[Victoria]

Hi everyone, when I went to a jewellers recently to ask about having my e-ring and split bands remodelled the jeweller said that he would not be able to reuse the 18K white gold from my current setting as reworking it makes it lose it integrity in terms of strength etc. Is that accurate? If so, is it useful for anything afterwards?

 

[WinkHPD]

Normally when making a ring using old gold it is necessary to add at least 50% new gold to avoid all sorts of problems with brittleness, pitting, etc.

Wink

 

[Gypsy]

Not to hijack... but is this the same with Platinum? I have a platinum necklace I don''t care for and was wondering if I could do anything with it other than sell it. Could I have it remade into something?

 

[lizz]

Victoria, you could have a new stone set in it (a colored gem perhaps). I really like your setting and think you could reuse it for, say, a RHR.

 

[strmrdr]

The problem is that its pretty hard to tell what its been mixed with and the metals that are used to mix with it dont mix together well in some cases and in all cases you have no clue what the results will be.
Jewelry alloys are carefully designed and the formula refined over years and in some cases decades to get the properties that are wanted.
When you get an unknown mix all that research and experience goes out the window.

In the case of a necklace the alloy used in them is not suited for rings it is designed to be cold formed in a chain forming machine.
That is not the properties you want in a ring.

When gold and plat is reused it should be refined to a pure state then re-alloyed and that can not be done on a small scale.

 

[Gypsy]

Great info. Thanks Strm. You never cease to amaze me.

 

[ilovesparkles]

Wow strm that was very concise and great information thanks!

 

[RockDoc]

One needs to know if solder has been applied to the old piece. One sure fire way to screw up the new casting, is to reuse metal that has the presence of solder.

If the old item has had any repairs to it, there most likely solder in it. In that case, you might want to use more fresh metal, than just the 50%.

There are small refining units that have been sold to jewelers. They can refine the gold on a small scale. Not many jewelers have this equipment - but if you find one that does, perhaps you could get a small amount refined.


Rockdoc

 

[Victoria]

Thanks to everyone for their insight, i definately feel armed with better knowledge!! Cheers..

 

[Garry H (Cut Nut)]

Storm is on the money.

But as well:
When hand making a piece we usually melt and cast a 6mm bar ingot and then roll that to say 3mm for a band etc - that compresses all the tiny air bubbles - but to do this propperly we usually need about 10 to 30 rings worth. 1 at a time under an ounce (31 gms) is dumb.
If a cast piece is being made then there needs to be a large lump of gold to force the metal into the plaster cavity (under centrifugal force or vacuum force.). A typical casting might have 20 rings etc on a tree form - and the sprue - or roots and branches will weigh 10 times the weight of the cast pieces.

Here is a mass production tree
http://www.gold.org/jewellery/technology/images/castingtree.jpg

 

[klavigne]

Garry,
There was a show on the Discovery Channel the other day that showed exactly how rings are made. I believe the shows called "how''d they make that" VERY COOL!!! The tree''s they had were only a dozen rings though, not that honker you showed in the link.