At a minimum what would I need to repair a fracture in a gold pendant?

Question

I have a dragon pendant that I am sure is 10k gold. I have had for at least 15 years. The tail of the dragon is exposed so it bends from time to time. Some time in the past a small fracture started. I do not wear it anymore since the fracture is quite large (in comparison to the width of the tail ~3mm).

It has been in a box for the longest time. I could take it to a jeweler but that is not something easily found in my town. It would be nice to know what is involved in the repair of this tail.

So, assuming I am correct about it being 10k gold, what tools and materials should I use to try and repair this? I have an old micro electronics soldering iron and some flux and solder but I dare not risk using them on something like this.

It is very likely that I will not be comfortable to do the repairs myself. It still would be nice to know what I can do though.

Answer 1

In my jewelry making course way back in 2000, heating metal for soldering required actual flame... a torch. You wouldn't want to do this with the equipment you have at all. It's a totally different process.

There are two different soldering methods in jewelry making: soft solder and hard solder. While many craft-y projects can be assembled using soft solder (that is, solder that can be melted using a soldering iron), working with silver and gold requires hard solder and a torch. There's a guide to it here.

"Hard" solders are alloys that melt at slightly lower temperatures than the corresponding metal pieces to be fused. Silver and gold jewelry require hard soldering. Copper, brass, and bronze components can also be fused with hard solders. In addition to requiring flux, hard solders generally also require the use of pickling solutions to clean and remove surface oxidation from the finished piece.

This matches my experience pretty much exactly. While we largely worked with base metals - copper, brass, nickel silver, etc - we did all of our soldering using a torch setup, flux, and pickling solution.

Metal workers typically use oxy/propane or oxy/acetylene torches with hard solder, but many soldering tasks can also be achieved with butane torches. Use a butane torch to solder jump rings, create ball-end head pins, make custom wire links and chain, create small bezels, fuse together small metal components, etc.

For your little project, based on this section, I'd guess that you could get away with using a butane torch but you'd also need to buy gold solder (to match the color), flux, pickling solution... which was always kept warm in an old Crock Pot.

Answer 2

Yes, working with solder and precious metals like gold requires the use of a torch, not just a soldering iron.

I agree completely with Catija's response, but in my jewelry making course way back in the 1990s (grin) I distinctly remember my instructor pointing out that solder cannot fill holes in material. So, it is good when you have a two flat pieces of metal and you want one of them to lie on top of the other...but you don't use solder to close jump rings (for example). Although you can use a butane torch for this task, you are actually fusing the rings by melting the silver itself just enough for it to form a closed circle.

My guess is a jeweler would most likely bring the two edges of your piece together as closely as possible, and then add a bit of new material to the section to be joined, to provide additional support and strength. Then once they fused these sections together, they would file and polish it to match the original finish.

I think it would take someone with a decent amount of experience working with precious metal jewelry to achieve a decent looking repair.