Hello! I'm Draven Umbra, and this is my little tutorial on how to repair a broken, cracked, or cut 14k gold ring.
The ring in question belonged to my late friend's father. My friend passed away unexpectedly which was really hard on her parents. This ring is her father's wedding band. It was made for him by a former student (he was an art teacher for a local high school) of his and it was very near and dear to his heart. My friend's fiance, adopted brother, and I decided that a way to lift his spirits was to repair this ring for him...and since I am the Owner and Operator of Black Sun Designs, it made sense.
So, let's get started with a bill of materials, eh?
- Borax. Yes, the laundry booster. No, don't question me. Sodium tetraborate has been used for hundreds of years to pull impurities from molten metals, especially during the Gold Rush. It's cheap, readily available at your local market, and what's left over can be used to make your clothes sparkly and new...Here in the midwest, a 72oz box of borax will set you back about $6
- A fire brick. You can usually find them at home improvement stores for under $20 to repair the inside of wood burning stoves.
- A file. You will make a mess. It's going to happen. Shhhhh...Shhhhh. Don't fight it. Don't fight it.
- Tweezers! Incredibly small stuff you will be working with. These make life better.
- Wire brush. You will have to clean up the area to be repaired. There's no getting around this. It has to be free of dirt and impurities
- Salt and vinegar.
- FIRE!!!!!!! No seriously, you need fire. If you have access to a Hydrogen torch, brilliant! Plenty of Instructables on here for building your own if you don't, but a Propane, MAPP, or Butane torch will work too...as well as a gas stove burner if you don't mind waiting a long, long time for it to heat the material. I don't suggest using a jewelry kiln for this purpose. It's best to see what you're doing and you run the risk of melting the ring completely if you use a kiln. That's no bueno. Don't be that guy...or girl.
- Long nose pliers. Yes, long nose. You don't want your hand by fire. Fire hurts. Fire bad.
- 14k gold solder. This stuff is kind of the nuts and bolts here. Whether it's a crack, a break, or a cut, you will need a medium to fuse the two ends together, and that's what the solder is for. The mixture of metals within it allows for the bonding of your new material to the old material, or old material to the old material. DO NOT USE ELECTRICAL SOLDER OR ANY OTHER CRAP FROM THE HARDWARE STORE! I cannot stress that enough, which is why I used the caps lock, and that even goes for Silver rings. I don't care if you used the plumbing solder that says "silver bearing" on it, you're going to get a very noticeable line of dissimilar metals. NO!
Alright, so let's talk solder. You need to know more, especially before you order what you need. In order to do the best, most unnoticeable job ever, you need to understand what you're working with. For jewelry solder, you're not actually soldering. This is important to remember. It's actually a braze. You're brazing the metal joint to fuse material into it. This is done at REALLY hot temps. Between 1380°F (727°C) and 1480°F (804°C). There are 3 different eases of solder, Easy, Medium, and Hard, and they all fall into those above stated temps. If you have a ring like the repair I did with multiple bands on a single ring, you will need to Hard Solder the center (1480°F;804°C) and Easy Solder the outer (1380°F;727°C). The point to that is that the Hard Solder will not become liquidus at the temperature the Easy Solder does. Even though they both leave behind 14k gold, that 14k is a mix of different metals that make the melting point different. It will make this sooooo much easier. On that note, I didn't do that. Take it from me, do it the easy way.
Step 1: Step One: Clean the Ring
Clean it. Wash it with soap and water, dry it off, go into your pantry and find vinegar and salt. Mix 1 teaspoon of salt to a 1/4 cup of vinegar, stir, and nuke it in the microwave for a minute or so. Drop the ring in the mixture and swirl it around for at least a minute.
This process is called "Pickling", for obvious reasons. The acetic acid in the vinegar and the sodium chloride make a pretty nice solution to remove any kind of oils or dirt or oxidation from the surface of the ring. Since gold, itself, doesn't oxidize very well at all, the oxidation it removes is from the silver, copper, and nickel inside of it. Yes, there's a touch of nickel in a 14k ring. It's used to make the mixture stiffer. This is why a 14k gold ring is tougher than a 14k necklace. But, I digress...
Now that you have your pickled ring, I want you to take that Borax (just a small pinch) and add a couple small drops of water to it. Not enough to completely wet it, but enough to give it some grab from the water's surface tension.
Since the Borax is ready to be applied, now let's get the rest of the mise en place assembled. Tweezers are EXTREMELY helpful. You'll want a small amount of the solder ready to go. Keep the pickle solution at the ready.
Alright, so, got the solder, the pickle, the tweezers, the pliers, the torch, the brick, and the Borax ready to go?
Let's start the torch...
Grab the ring with the pliers, being careful not to mar the surface of the ring with the teeth the pliers may have. Natural instinct is to squeeze hard, but you will make life harder on yourself since you will have to file and sand the marred surface. Now note where the crack or break is. In the picture, it wasn't hard for me to know where it was since I also had to add material to the ring. This might not be your case. You want to heat as near the part you're repairing as you can without actually heating the crack. If you're not using a hydrogen torch, you're burning a hydrocarbon. You will leave carbon soot behind if you heat the crack directly which will stop you from doing a good repair. Carbon doesn't burn. You'll want to heat the ring until it starts to glow. It will first turn red, then a reddish orange, and then start to turn into glops of yellow metal drops on your firebrick. When it gets reddish orange, you've heated it to ~1500°F. Gold melts at 1945°F. Pay attention to the glow. It's cool.
When you've heated it to its glow, let it cool a tiny bit, take the tweezers in your free hand, grab a tiny piece of the solder and place it directly over the crack. Then, grab a piece of the wet borax and put it over the solder. You'll notice the borax begins to first expand...return the ring to the flame...and now it liquefies. As it begins to liquefy, it will grab whatever oxides or carbon is blocking the solder from flowing into the crack or break. This is why I didn't tell you to grab any kind of flux. It is flux. You may have to rinse, lather, and repeat on that step depending on the solder flow, the borax, or whatever. Nothing ever happens perfectly.
When the ring cools, you will notice the borax looks like globs of a reddish, glossy glass on the surface. You can file it away, strike it with a deadblow hammer to bust it off, use a metal pick...whatever. The choice is yours on removal. You can see what I mean in the picture. The ring will also have incredible amounts of firescale on it. This is where the pickle comes in again. Nuke it in the microwave, drop in the ring, stir stir stir. It will take a while for the pickle to remove the majority of the firescale. If it gets cold, heat it again. The pickle will start turning green. That's cupric chloride being made. The chlorine in the salt and the water in the vinegar are combining because the pH of the acetic acid to make hydrochloric acid, which then robs the firescaled copper from the surface making cupric chloride. That's how you know the pickle is working well.
When the firescale is mostly gone, you can look closer at the crack to see how it went. If you need more solder to fill it, add more solder, if not, time to make it pretty again....
Step 2: Clean Up Your Mess...
Remove all traces of rework. File, sand, polish. File away huge globs, sand them smooth with progressively finer grit (I recommend 300 to 600 to 1200 to 2500). You still won't have a perfectly shiny, smooth ring until you apply jeweler's rouge buffing compound. This, also, is available at hardware stores. It's used for nonferrous metals, or metals without iron. If it doesn't say, specifically, "Non-ferrous", don't bother. Use toothpaste before you use chrome or ferrous buffing compounds. It will take longer, but it will work better.
Step 3: Done. Revel in Your Masterpiece
Enjoy your work.