soldering jewellery

Hi, I have a pendant in my WIP that has been soldered shut and I want my character to open it. The pendant is currently porcelain but can easily be changed to silver. I have been researching all afternoon a simple way to dissolve the solder but it all seems very complicated. So far the easiest I have seen is to use a propane torch to dissolve a silver solder on a silver pendant - but wouldn't this also begin to melt the silver pendant? There is tonnes of information on how to do the soldering, but very little direct information on how to dissolve it (it all seems to depend on this and that - all of which means nothing to me).

Is it possible to simple cut open the pendant?

Thanks for your help.

 

This is just my speculation. How was the pendant soldered in the first place? I would imagine that, if the pendant didn't melt the first time, couldn't the method be slowly increasing the temperature of your fire/torch until the solder starts melting? I know metal changes the first time you heated it but I doubt the property would change that drastically.

 

How is it soldered? If it is soldered shut from the inside (i.e hot metal is poured inside and then it is closed shut and cooled) then it becomes very hard to open it again. However, if it has been soldered from the outside while already shut, then you could, depending on the quality of the soldering, scrap or break it off. Otherwise the use of high temperature been applied in a small location can be used to soften the metal enough to be able to open it again. Also, on a different note, you rarely ever solder something shut with silver. The typically metals are those with low melting points like lead. Extra points goes to if they are cheap and readily available. Silver is very expensive so unless you have a lot of money to blow you wouldn't do it with silver. That is, unless you are soldering it shut and still want it to look the same as it did before. At which point the soldering would be very fine and silver is also not a very strong metal.

Edit: Metal properties can change drastically depending on how it is melted, cooled and forged. But in soldering typically there is almost nothing done to change the metal's properties as it serves only to seal something shut.

Re-edit: There also other ways than to melt the metal that forms the solder. For example, applies a strong corrosive or aciditc substance can be used to weaken the metal. Or otherwise cooling the pendant to extreme temperature and then applies a short and sharp shock will result, if done correctly, that the solder will simply "shatter" due to being made so brittle as a result of being so cold.

The way I remove solder on watches is using a pen-like device with a tip that becomes very hot. I then simply dab this on the solder and simply scrap of the heated and therefore soft metal. But also don't know how much technology is avaible to you.

 

Thanks guys. Its been soldered from the outside. The pendant was given to my character when she was a child. Now she is an adult she wants to open it because something is making a rattling noise inside and she wants to see what it is. She's tried prizing it open but is afraid of damaging the pendant. Now a guy has turned up and is offering to help her open it, says he's had an idea - but it has to be something reasonably easy, i.e. not a precise mixture of chemicals to dissolve the solder, that's why I was hoping it could be cut open somehow. I like the idea of freezing it - I could work with that. If I go with the silver pendant, rather than porcelain, then it will definitely have a silver solder, unless you know how to solder a porcelain pendant and if it's any easier to open once soldered?

I also read that a soldering iron won't get hot enough to melt silver, only a propane torch would do it, but i don't imagine that would be very precise given it's a small piece of jewellery?

I guess if it's too difficult I can come up with something else. It was originally just stuck shut but that felt a bit lame. Or maybe it could be glued shut. I still prefer soldered shut though - feels more permanent.

BTW - the item inside is very precious and rare, hence the reason for soldering.

 

Okay, I did some quick research since I've learned a (very) little about soldering, and according to this page, "silver" solder is called that because it "often contains silver". Often, not always. From the same page, silver solder melts at temperatures greater than 420C, while silver (no further information on grade, and I don't know what's best/most common for jewelry) melts at 961.8C, so you should be able to solder the locket shut, and later release the solder with heat, without damaging the jewelry itself.

Make sure, however, that the important rattly bit inside is also relatively heatproof. Diamonds can catch fire at around 800C, but they'll degrade to graphite at about 700c (this is all quick googling to confirm half-remembered facts), and it looks like pearls can have bad things happen to them too.

Hope this helps, and if anyone knows better, please please please correct me.

 

If it's porcelain than you would probably use a wax or rubber based solder. Otherwise, if it uses a metal based solder than usually something else is done to the porcelain to make the solder 'stick'. this page goes into a bit of detail but in short, metal-ceramic soldering is weaker than metal-metal. However, also do remember that ceramic is quite fragile though it is one of the most heat-resistant materials we human currently know of (There is a reason it is used in blast furnaces, spaces shuttles, and it is why it is used as material in forges to melt the metals in).

Mind you, it also depends on what kind of ceramic it is and how pure it is. Some people, like the romans for instance, included various inpurities such as saw dust, broken pot pieces, stones, straw, etc.. into the ceramic for certain desirable traits.

If it was a silver jewellry that had been soldered shut from the outside, then the way I would remove it given a low-technology scenario would be the to scrap of as much 'excess' solder off before then going with something that looks like this to try and clear as much of the solder off. Mind you, this is the most 'primitive' way i can think of rem,ove the soldier and it is neither efficient nor fast and certainly does not guarentee an intact piece of jewelry. However, that said any decent jeweler would be more than capable to repair the silver if needed. Thought, depending on the damage it might not look the same.

Personally, I recommand going for a silver jewel and using a nickel-silver based solder. Silver was extremely expensive in previous years and nickel silver, a far inferior metal (but harder), was used as it was cheaper (made from an alloy of copper, nickel and zinc). However, nickel-silver will melt at about 400C while pure silver will melt at 900C. It would then be possible to simply throw the jewel into something able to reach a temperature of 500-600C and simply wait. You do not want to get too close to 900 (I would say 800C would be cutting it close). as you risk deforming the metal. Also, depending on the technology it might not be pure silver. I was told, that as a rule of thumb you don't go within 20% of the melting temperature of something you do not want to deform, melt, or otherwise. This is due to the 'grain' of the metal. heating the metal allows these grains to change and alter the properties of the metal. If you wish to know more about metal grain, here's a quite crash course on them.

Now if it was ceramic, and depending on the ceramic with a metal based solder, then you could simply heat it up. I believe porcelaine usually melts about about ~1400C. Clay at ~1800 and depending on the ceramic this number can go all the way up to 3000C and over. Mind you, impurities within the ceramic can dictate the melting temperature. A bit like how adding salt to water lowers the freezing temperature.

Just as an FYI. Most forges can reach 2000C in perfect running conditions. But typically, a smith would not got that high. Also, the fuel used can change drastically the temperature of the forge. For instance, a standard, run of the mill, wood-fired forge can usually reach no more than 500-600. A good coal fired forge can reach up easily 3 times that limit.

 

Why not use a soldering iron?
Quite a bit safer than a torch.

Also what is witchcraft you speak of?
How do you turn porcelain into silver?
You must share this bit of alchemy.

 

I would suggest that the original solder work was faulty, in that the solder looked fine but it developed a crack shortly after that went unnoticed. This way, only a little bit of strength is needed to apply sufficient torque. I've actually seen this firsthand.

 

Okay, not sure what's going on with my posts and the moment but the above reply was NOT supposed to come up as one big quote. Note to all: please open the above and read, my replies are all in there. Thanks

 

@Viridian No I did not 'hack' your account. It is much simpler just to ask you.
Though if your account was hacked try making your password a bit more secure.
I know only what you have posted on this thread about your work. Though it is
good to know that you can use ordinary solder on magical items.

 

@Cave Troll, good to know it wasn't you, though I meant my laptop, not my WF account. If my WF account was hacked I suspect the hacker would be very disappointed - indeed if my laptop truly was hacked I suspect the hacker was still disappointed!

 

Assuming the locket was soldered shut, some time after manufacture, without damaging it or its contents, it should be possible to remove the solder.
Using a soldering iron to melt the solder which can then be absorbed, by capillary action, into a metal wick.
The metal wick is just that, a cord made from very fine wire, usually copper as it's easily worked. You might need a flux to encourage 'wetting out'. Fluxes need to be mildly acidic, pine sap (rosin) has been used for centuries.
This technique is used all the time to remove solder from electronics boards.

 

Great discussion, was watching it yesterday and got my thoughts in order.
First of all, if you look up antique porcelain pendants, you will see that most had/have a metal framework, usually gold; this was done to ease joining, add color, add strength, and greatly reduce finishing times. Porcelain is either cast, or formed by hand. What shape or configuration is the pendant? Each maker makes a slightly different shape. Some are spherical, others are like a dried gourd.

I am going to go off topic for this; it is how I think when I see this. I have so many questions, just from this.
Did it just start rattling?
If so, something broke from the inside.
Why did it break?
Why now?
How was it joined to the inside?
Is she supposed to find this thing?
Is it a plot point?
If she is supposed to find it; how was the break planned?
If it were porcelain, with a metal frame, and then sealed, and she wore it since little- Human nature tells me that she would have spent her years running a thumbnail along the join when worried, thinking, stressed, bored, etc. Does that play into something detaching inside? Did she rub a spot raw, thus breaking a join that held the thing inside? If so; Is there now a small hole were said item detached?

This is just the start of my questions from that sentence. Do a little more research, and try to think through what this pendant has been through over the years.....nothing enough to break it, but was in daily use.
It is worn.
Is it still pretty?
Have all the decorations long since rubbed off?

Most porcelain pendants that were made of only porcelain contained holes; it is due to the nature of how porcelain works and the limits of casting technology at the time, they were made in multiple steps (stages).

 

Thanks for taking the time to consider this @antlad, much appreciated. The pendant recently started to rattle after a specific event, bearing in mind that there are magical elements to this story. The MC has had the pendant since childhood but it was more of a talisman than anything else and when she reached a certain (young) age it was no longer needed, put away and forgotten about. Now she is an adult (and it is in her adulthood that something happened thus causing the release of the crystal inside - though I have to admit I haven't yet figured out how it didn't move around previously) and has recently lost a close relative, the same relative that gave it to her in the first place, she has taken out the pendant and started to wear it again. It is a huge plot point and something that she's completely unaware of. At the moment, she's just curious as to why there is something suddenly rattling around in there.

I suppose, given there are already magical elements, that the pendant could just open of its own accord at the right moment - but I don't want to get too fantastical, that's why I wanted a way to open one that is sealed without going into too much detail about technicalities and also in a way that someone who knows nothing about jewellery, soldering, porcelain etc could do. I thought the fire would be a good idea, I have a way that it can end up (accidently on purpose) in a woodburner, only to be discovered within xxxx mins and retrieved, and hey presto - the soldering has melted and the pendant opens - though of course I will have to find out just how long it would need to be in the fire for/how hot the pendant is likely to be when retrieved etc. Perhaps I should stick with the Harry Potter version and just magic the ruddy thing open *sigh*.

 

Magic made the crystal grow, after a certain time, the crystal 'matures' and detaches, thereby signaling the next adventure. Since magic is involved; maybe the porcelain goes 'clear' at about the same time? At that point it would be as easy as a hammer and a nail to break the glass.
Maybe the crystal matures, drops, glass clears, crystal glows and wakes her?

 

If it doesn't need to be soldered, why not something more mechanical, like a catch that the character doesn't understand but eventually puzzles out? Or the opening side is soldered shut, but the character figures out that, oh, they can take apart the hinge on the other side?

 

Not my story, but I like that idea enough that clicking "like" doesn't cut it.

 

A diamond coated rasp could wear down the solder.

 

Apologies for the lateness in replying - the festive season is of course to blame.

All great ideas that I am definitely going to work with. So glad I put this question on here