Annealing silver is one of the basic pieces of hot work you need to learn. For many projects, it’s a requirement for success that you really can’t skip. For the new smith, however, the whole process can seem to be an enormous undertaking.
You’re in good heads. Read on and we’ll discuss annealing, how to anneal silver, and when you should do it while working on your next project.
Table of Contents
- What Is Annealing?
- How Often Do I Anneal My Silver?
- How Do I Anneal My Silver?
- Annealing Larger Pieces
- Annealing Coils for Wire Wrapping and Weaving
What Is Annealing?
Silver, and other nonferrous metals, get work-hardened while they’re being formed. All metal is actually crystalline in structure, and after a certain point, that crystalline structure becomes stiff and unyielding.
Annealing takes stress off of the crystalline structure, yielding a softer form of metal for you to work with. You can even anneal a piece several times during the same forming operation to make it go smoother on yourself.
Annealing silver is a relatively easy task, and you can undertake it with just a torch and a container with water.
It’s also one of the most vital tasks to learn in the workshop for those new to silversmithing. Along with soldering, it’s a basic heated operation that you’ll need to learn to have any kind of long-term success.
Learning how to do it properly takes time, developed heat control, and a bit of patience.
When I began, I actually didn’t have much to go on but a couple of paragraphs on Facebook groups and a page out of McCreight’s The Complete Metalsmith. It worked, but I had a lot of frustration getting there.
But here’s the simple way to describe annealing: annealing is a heat treatment designed to increase the ductility and decrease the hardness of a metal.
How Often Do I Anneal My Silver?
The short answer?
Whenever you need to.
The longer one?
You want to anneal with the metal becomes too hard to work or is too hard to form in the way you want.
It’s hard to give exact guidelines other than testing the metal yourself and getting a feel for it.
Some good signs you should anneal:
- Wire becoming too hard to manipulate by hand.
- Hammer is no longer moving metal while forging.
- A rolling mill takes exceptional force to use, try to catch it before a roll fails midway.
- Your sheet metal begins to buckle and warp during a hammering operation
Do it more often if you’re casting ingots or melting chunks to work with at home. I’ve found that any silver that may contain a bit of oxidation or too much solder tends to become brittle much more quickly.
How Do I Anneal My Silver?
The actual annealing process is pretty simple. The studio process is almost always done with a torch on the bench, but if you have access and time you can get more precise temperatures with a kiln.
You’ll need a torch, a fire-safe surface, some tweezers, and a quench container.
- Place the metal on a heat-safe surface.
- Torch to annealing temperature.
- Optionally, let the metal cool a bit then bring it back up to temperature again. 2-3 cycles will complete the usually recommended 30 seconds at temperature.
- Allow cooling to black heat, where the surface is no longer glowing.
- Pick it up with tweezers and pop it in the quench jar. Enjoy your sizzling.
This underlies a surprisingly complicated process that’s hard to teach. You should also know the following.
Heating Temperature and Time Tips
Sterling silver, for instance, has an annealing temperature of roughly 1100°F or 593°C. The exact temperature depends are there are a few slightly differing sterling compositions. The highest will be around 1200°F or 650°C.
That’s ideal, and unless you have temperature measurements on your piece during the process you’re going to have to find another method to find the ideal way to do it.
There are a few tips that people will give you, depending on their background and experience.
Watch The Color of The Flame
My go-to method is to wait for the flame to turn bright orange. When it does, I pull heat and inspect. Depending on lighting the metal is almost always either dull red or just starting to turn goldish.
Watch The Metals Temperature
Some people just watch the metal’s temperature. It’s doable, but it takes a lot of time and in most workspaces, you’ll have to turn off overhead lighting.
The Sharpie Method
You can also mark the metal with a Sharpie and wait for the flame to cause it to disappear. I go back and forth on recommending this method, but it’s recommended by people whose opinions I do respect greatly, such as Andrew Berry.
What I do take issue with is two things:
- It’s really easy to destroy your mark too early if you’re not good with torch movement. Spot heat destroys the ink just as effectively as heating the whole piece.
- It’s technically a bit too cold since Sharpie on silver disappears at roughly 923°F (500°C), which is a bit shy of the ideal.
I learned the Sharpie trick by working on aluminum and copper bits with a machinist. When I asked one of those old, crusty, silversmith types he insisted it was too inaccurate to be worth it.
I don’t necessarily agree it’s too inaccurate, but I find it a bit imprecise.
I get more consistent results with waiting for the flame to turn orange and then pulling heat. My bigger issue is that you can’t cycle annealing very precisely if a mark that disappears the first time the piece hits temp isn’t there any longer.
Frankly, you’re not going to overheat the metal with the Sharpie method, which is a much bigger problem for those new to working silver than not heating enough. Most of us tend to think “big flame, red metal” when we’re starting out and my definition of “dull red” is about five shades lighter than when I started.
Then we try to figure out where we went wrong with black, or even copper-colored, silver after trying to anneal. If you’ve got black oxides forming instead of a matte greyish color you’re probably a bit overheated.
You got it too hot. That’s all. And that can disrupt the alloy, bringing the copper to the surface, or creating a heavy fire scale on the surface.
Just pick a method, stick with it, and tweak it until you’re happy with the results. I recommend learning to cycle the heat to 30 seconds or so in a controllable fashion as well, but many people are fine with just quenching at black, or even red, temperatures.
The only time where overheating will cause serious problems in the studio is if you reticulate the surface. This surface deformation from heat can introduce oxides back into the metal which will have to be abraded and may go too deep into the metal for quick clean up in some cases.
Annealing Larger Pieces
When you’re annealing at home you’re probably using a smaller torch. Something more akin to a creme brulee torch than a serious oxy-acetylene setup.
These don’t even have to be large by weight, a piece that annealed fine a bit ago can become a serious pain after some rolling or after soldering more pieces to the whole mess.
One of the most frequent precursors to my work in the workshop is producing these rods for instance:
There’s a lot of intense spiraling, delicate curves, and other structural issues that require annealing. I use a butane torch on an 8” brick, annealing these in one go isn’t going to happen.
These are usually too brittle to even bend at 90 degrees when the final mill pass has been undertaken.
So instead, I’ll do the following:
You need to heat the central portion of the wire to annealing temperatures. Get as far as you can, but with very thick wire I’ve sometimes only been able to do one section in the metal a ½” or so long. Metal that thick usually requires a hammer to move.
After folding, you go back over the central portions on each side. I use a pill bottle “spool” for this purpose to keep an even curvature. This is strictly done for storage unless I am shaping a very large wire cuff.
For larger pieces of sheet, working at home may require you to be creative. Cut fire brick “kilns” are my go-to, just sliding in the metal and pouring heat into the rough structure can bring good results as long as you can see clearly.
Annealing Coils for Wire Wrapping and Weaving
Most of the wires you buy for your wire wrapping and weaving are dead soft and suitable for these purposes.
But occasionally you may have issues. I’ve found 22-28g copper pulled from stranded electrical wire to be a bit too hard for actual weaving for instance. Solid strand wire bigger than 20g often has the same problem. It’s malleable, but not loose enough to work exactly.
So what is there to do?
There are two basic approaches to wrapping yourself a coil:
- Coil the wire in on itself- Quick, easy, but costs you a bit of the end of the wire in most cases. That’s fine for copper or brass, regrettable with silver, and downright terrible for gold alloys.
- Use binding wire- I keep a spool of 24g copper wire I bought years ago that was too stiff on my desk. I’ll put a small kink on both sides of the coil, just a 3-4mm long stub, and then coil it. The binding wire will keep tension on the tabs from unspooling while heating for annealing and can be easily removed.
If you’re planning on using the wire for weaving, you may want to straighten out any kinks after annealing.
After that, anneal as normal and unspool as needed!
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