Annealing copper.

[maroun.c]

Not trying to be cheap as I've seen many comments about annealing linked to a cheap practice....
Yet i had to pay 60usd in shipping plus customs to get few small rolls of copper here (less than 2 kgs total)...
I was able to find rolls like this, especially of smaller diameter copper from shops that work with electrical motors.

Does thinner wire 0.5, 1,1.5 mm copper require annealing or is it.possible to work with it as is?
If I am to anneal I'll be heating it on my barbecue using charcoal. Do I place it k the fore or wait for the fire.to turn down and just place it above hot charcoal till it gets red?
Thanks for any input.

 

[just.wing.it]

I've done it on a glass stove top with good success.
I wrapped the spool of wire with smaller wire to get good contact between all of it, flipped a few times, water quench.

Coals will probably be easier and quicker.
I'd put the spools as close to the coals as possible, maybe straight in the coals would be ok, I doubt that coals get anywhere near the melting point of copper.

 

[Sansui]

Hi, Keep in mind that magnet/motor wire is coated with an insulating varnish material and will create fumes when heated. It may leave a residue within the coiled wire. Try a test batch first. Let us know how it turns out.

 

[penumbra]

When I used to anneal copper wire years ago, I did it outside in a burn barrel with wood. I got a good fire going with coals, tossed in a spool of wire and dug it out of the ashes when it was cool. It did a great job for me and I loved the mottled look of the wire that fire produced. I may get around to doing it again someday.

 

[Sansui]

I have used a MAP gas handheld torch for small batches with good results. I heat the wire coil placed over two fire bricks. I do this with 12 and 14 gauge electrical wire.

 

[Shibui]

Overheating will make the copper brittle or melt it so you do need to watch it on a fire. I get the fire going well with good red hot coals as well as some flame, toss rolls on and watch till they glow red. No need to quench, just hook out the hot rolls with a long bar or stick and set them aside to cool down. Beware that copper can retain heat for some time so take care when picking the rolls up after. Uneven heating can give hard and soft patches in the wire so aim for an even heat right through all the wire.
Thinner wire may be OK as it is. Some new rolls may be soft enough to use without annealing. You will need to test some to see how well it bends onto the tree before deciding to take the trouble to anneal. If in doubt, try some as is and some annealed and decide which is better.
You will probably need a good fire going on the charcoal BBQ to anneal thicker wire properly. It needs to get red and that does take some heat. Thinner wire heats quicker so you will need to do some trials to find the right combination of fire and time for each sized wire.
I agree with Sansui above. Even though it looks copper coloured, that wire probably has a thin insulation coating so burn outside and avoid breathing the fumes.

 

[TN_Jim]

A buddy of mine was taught to use a torch in a metals class, that’s what he recommended to me, had trouble with very heavy wire and propane but I know this method (good torch) is good.

I’ve always thrown it in a fire and left it with success; however, the last time I did this the fire was evidently way to hot and the wire came out very brittle...it was a waste of good copper.

In the future I will get it out when it becomes scorching red and not leave it.

Careful with the thin, if any wire is flexible (thin usually is) it may not even need annealing. In this case I’d practice on a random branch -if you have to fight it, anneal it.

 

[Potawatomi13]

A fellow club member uses his kiln for this. He loosens the coil so looks kind of like semi compressed spring. When is hot enough to collapse into the original coil again is done. Do not know if he dunks in H2O.

Thin wire goes on thin more delicate branches so best idea to anneal also.

 

[penumbra]

If the metal cools slowly it is annealed. If it cools rapidly it is tempered. That is why I let mine cool in the ashes of a wood fire and retrieve it the following day. It has very little to do with the actual temperature as long as it is below melting point which is nearly impossible to achieve in a small wood fire.

 

[leatherback]

If the metal cools slowly it is annealed. If it cools rapidly it is tempered. That is why I let mine cool in the ashes of a wood fire and retrieve it the following day. It has very little to do with the actual temperature as long as it is below melting point which is nearly impossible to achieve in a small wood fire.

Hm.. I thought tempering was a process specifically for iron alloys?

 

[penumbra]

Hm.. I thought tempering was a process specifically for iron alloys?

Bronze weapons were always tempered and of course glass is tempered too. I'm sure there are plenty of other examples. Tempering imparts hardening but also makes it more brittle. Annealing is the opposite. THe process is best known in high carbon steels.

 

[Adair M]

Bronze weapons were always tempered and of course glass is tempered too. I'm sure there are plenty of other examples. Tempering imparts hardening but also makes it more brittle. Annealing is the opposite. THe process is best known in high carbon steels.

Iron and copper are different. Iron is an alloy, and reacts differently when quenched than does copper.

 

[penumbra]

I agree that they do temper differently when quenched and I have applied this process with high carbon steel to make blades. I don't quench copper as I have only annealed it to make it softer.
Iron is actually not an alloy. It is the most abundant element on earth by mass. It makes up most of the earth's inner core. Steel, in all of its forms is an alloy containing iron. Iron is seldom found in a pure state and therefore could be mistaken for an alloy. The purist iron is found in meteorites.

 

[Adair M]

I agree that they do temper differently when quenched and I have applied this process with high carbon steel to make blades. I don't quench copper as I have only annealed it to make it softer.
Iron is actually not an alloy. It is the most abundant element on earth by mass. It makes up most of the earth's inner core. Steel, in all of its forms is an alloy containing iron. Iron is seldom found in a pure state and therefore could be mistaken for an alloy. The purist iron is found in meteorites.

You are correct. I mistakenly typed “iron” when I meant “steel”. Bronze is also an alloy, and tempering affects it, too.

But, back to copper...

Annealing works best if the copper is heated to about 1/2 it’s melting temperature. You want a nice, uniform, pink glow. It’s not necessary to heat it to red hot. At that point, the crystalline structure is aligned, and the wire will be soft. It doesn’t matter whether it gets dunked in water to cool off quickly, or if it cools slowly.

The only advantage to cooling it quickly in water is that might knock off some of the oxidation on the surface.