Dagmar, I couldn't find one online that wasn't too involved or technical, so I wrote up that description of the annealing process, etc. again this morning and I saved it this time.
It probably sounds fairly didactic, but here it is:
Annealing metal jump rings
What you will need:
Fire brick or Ceramic tile: the kind of fire brick used in fireplaces, not the kind used to line the walkway outdoors...or a high heat fired ceramic tile, such as used in the bathroom behind the tub, samples are fine.
Fireproof base: something sturdy metal, like a cake pan or small cookie sheet.
Flux: Commercial flux for the jeweler, not the stuff in the hardware store, or, I make my own in a small glass jar, baby food jar or small spice jar, with 2/3 boric acid, from the drugstore, 1/3 borax, from the laundry aisle at Wally World or grocery store, fill this up with wood alcohol, from the hardware store, and shake it to blend. Don't use rubbing alcohol. A good fitting lid is best as the alcohol evaporates.
Small paint brush: An inexpensive paint brush for children is okay, use a wider one rather than a tiny pointy one.
Pickle: Commercial pickle for the jeweler, or, I make my own in a small crock pot for potpourri liquid or even a small coffee cup, put some warm water in the container and add a teaspoon or two of alum to the coffee cup, a tablespoon or two to the crock pot. The warmer the water and the more alum the quicker the pickle will work to remove the residue from the flux.
Tweezers or pliers: Something with a wooden or otherwise insulated handle, to be dedicated to this use. Cheap chain nose pliers work well.
Length of copper wire: 18 gauge or larger bent at one end into an L shape, to remove the jump rings from the pickle. Don't use steel to do this as it will react with the pickle to create a plating solution.
Sunglasses or dark safety glasses: For safety and to better judge the color of the metal as it heats.
Torch: A plumbers torch is fine for this, from the hardware store, and something to light the torch with such as a striker or a candle lighter.
Set up like this:
Put the firebrick or ceramic tile on the cake pan or cookie sheet and put a few jump rings on top of this. Then dip the brush into the flux and paint the jump rings with just enough to cover them. This prevents the metal from oxidizing and discoloring badly and is also a temperature indicator. Move the flux away from the table you are working on so that there is no chance of accidentally getting too near the alcohol in the jar with the torch. Set up a small cup or jar with some room temperature water near the work station, and set up another cup or the crock pot with the warm pickle in it nearby as well. The pickle should be about the temperature of a nice hot cup of coffee (not Dunkin Donut's...that's too hot).
Put on your dark glasses. Fire up the torch with either a striker, which may or may not be provided with the torch, or a lighter...candle lighters are great for this as you don't get your hands too near the gas. Adjust the flame of the torch so that you can see a well defined blue flame coming from the tip surrounded by a less well defined orange/yellow flame. The blue flame should not be extremely sharp, nor should the torch sound like it is hissing loudly like an angry cat. You want the flame to be a medium large, medium hot flame.
Apply this flame to the jump rings, moving constantly over them with the orange part of the flame until the flux begins to “melt”. The flux will start out looking like a whitish powdery substance and when it melts it will turn shiny, clear, and liquid-looking. There may be some small temporary flames from the alcohol in this particular flux, this is normal and they will die down in a few seconds. Commercial fluxes don't usually produce flames like this.
At this point, the metal will start warming up. Keep moving the torch constantly over the jump rings and watch to see when they start to turn a dull red. This is it, this is the temperature you want them to be, so remove the torch and turn it off.
Using the tweezers or pliers, pick up the jump rings and put them into the cup of water to quench them. Then remove them from the water and put them into the pickle cup or pot. The pickle will remove the discoloration from the flames in ten minutes or so and the jump rings will look satiny or matte...they are done then and can be removed from the pickle with the copper wire, washed, and shined back up with a cloth or buffer. Now they are annealed and will not break as easily when you use them.
The opposite of annealed is work-hardened...if they are too soft you can harden them back up a little by opening and closing them a few times.
That's it!
This isn't a very technical description of this process, there is a lot more to actually understanding what is happening to the metal, what particular fluxes and pickles work best, which torch is best, etc., and I think it's a lot of fun to learn about all that. But for simple annealing of jump rings, this works, and it isn't necessary, unless you want to, to understand all the technical things.
I hope it helps...if you have questions I'll try to answer them...
Pam 