removing solder from gold

[treasureman]

Bit of a dilemma here. I have these beautiful ancient pure gold coins that were solded into a brooch some time ago. I want to remove these coins from the brooch the best way possible.
ive read a few trestments. Heating to a degree where the solder melts and the gold doesnt. Releasing the coins.
or ive read that an acid bath if pure gold so the solder disolves and the gold remains intact.
a jeweler told me he would file in between the brooch and the coin but to me that sounds quite abrassive and damaging.
would love to here your advice/ knowledge to remove these the best way possible.
thanks in advance.

staining from the other alloys is getting quite bad where the brooch is joined

 

[user 1769]

I would leave it as is, treasureman. The coins themselves might be damaged enough to lose significant value anyway, and the brooch looks old. It's a good example of what people used to do with coins.
I'd personally be too worried about causing further damage to the coins, and ending up with something more unsightly than what you have already.

 

[MJB]

hey treasureman, solder will melt away way before the gold does if you really want to separate them. A small flame from a lighter...one of those jet style ones should be all you need which will not melt the gold. If it is not just solder and something like silver solder or it has been brazed then things change.

I would take it to a jewellery store that mount nuggets on chains, they will know the best way to do it

 

[RotGrub]

I'm with mfdes on this one treasureman. That's a pretty cool broach, how many other people have one of those? Its like a miner's 3 star medallion and would look dam good on your carhartt jacket!

 

[Tathradj]

Nitric acid.
Will dissolve lead and silver but not gold.
.
Do your research first like I have but all are saying to use a diluted solution.
.
I have seen that type of brooch before.
It stood for prosperity.

 

[Simmo]

When I make up nugget earings and the like, the 'solder' used is simply 14 carat gold wire. Its just that it's mass is less than that of the nugget and post, so it melts first, however the nugget and post have to get darn hot for the flux to move the solder around to get a good bond

I would say a fine 'pencil beam' burner, directly where the pieces are joined, and try a little force to prise apart. Lift each fixing point a tad, then go to the next, keep going back and forth 'till it comes off.

I dont think you will get all the solder though, and the coin certainly wont look mint!
I agree that leaving it as is or transposing it into another piece, masking the 'repairs'?!

Anyway, good luck!

 

[Ronk]

why not get it valued as it is and ask about if taken apart
then definitely get someone that works with gold to separate it if you decide to go that way

 

[treasureman]

All the advice is greatly appreciated. I thought using a jetlighter would damage the coins or not? Would it be that easy and they fall off the brooch? I may just leave them now. But just wanted to see howd treatments would go as the back of the coins still have good detail.

 

[thedigger]

My advice is to leave as it is,because you might remove the bar,but the solder will remain,and it will ugly on the coins.
There is nothing worse than gold solder on a nugget,and it flows with heat.
This is coming from years of experience
Regards Frank

 

[treasureman]

Thanks again. Ive left it as is. Very b appreciative of everyones advice

 

[Rustyone]

This is probably a bit late but this is for future reference. DONT USE NITRIC ACID on gold coated items. It will attack the substrate and lift the gold off the item. ie: we use nitric to lift the gold coatings from computer CPU lids and other items. The best way is to simmer the item in full strength Hydrochloric acid (HCL). This will dissolve base metals including the solder.

Regards
Russ