annealing copper wire

An electrician friend has given me miles of copper wire of different
gauges and I want to anneal it, what is the best method to get an
even result?.

Alex

In the past I've got excellent results from throwing loose coils, after stripping off all the plastic with a knife, into the embers of a bonfire. Wait till it glows dull red and then remove with a stick and drop into a bucket of water. I've read that a newspaper fire works just as well. There's a good article from Marty Weiser on Brents site here. http://www.evergreengardenworks.com/copperwi.htm

I have loads of scavenged wire, being an inveterate skip (dumpster) diver and find that, after stripping, a few minutes in freshly lit barbecue coals before it settles down for the Chicken Tikka and burgers et al does the job a treat.

You could slot that activity in before the Dragon summer barbies



TimR

Thanks Kev & Tim will give it a bash!.

Alex

I've read that copper wire needs to be annealed, but I'm wondering why?

Annealing makes the wire more pliable by restructuring the crystals. After bending, it work hardens and holds the bends more effectively than aluminium. Annealed copper wire slowly loses its pliability and may eventually need re-annealing.

I also want to anneal some lg. gauge copper wire from H. Depot. A friend told me I can use my gas grill, fire till red and drop in water. Great. But my other half is worried about any by products that might ruin the grill for cooking food. Is this a real concern or am I fine using our grill safely?

Thanks!
Chris

As long as the plastic coating is stripped, you're OK.

Excellent Jim! Being married, we always have to keep the other happy lol I'll do it when it warms up a bit more to conserve lp gas.

I have some wire that was given to me that had been burnt to remove the plastic, and other wire that was purchased as bonsai wire. How do I tell if its been annealed? If you dont put it in water after being in fire then it will not anneal? Is the copper colored aluminum wire, aluminum colored in the center of the wire? If im not sure if its annealed or not, does it hurt to just burn it all again to ensure its annealed? the advantage of annealed wire is that its easier to wrap around branches?

bucknbonsai wrote:(1)If you dont put it in water after being in fire then it will not anneal? (2)Is the copper colored aluminum wire, aluminum colored in the center of the wire? (3)If im not sure if its annealed or not, does it hurt to just burn it all again to ensure its annealed? (4)the advantage of annealed wire is that its easier to wrap around branches?

1. It will. Copper is one of the weird materials that will anneal either by slow cooling or fast (quenching).
2. You lost me here...but aluminum colored inside is aluminum...just coated for looks.
3. No, you can repeat the process and should be fine.
4. Yes...because the wire becomes "uniform" through out (hardness, malleability, etc.).

Do not overheat or let it stay in fire longer than necessary, else you risk damaging the wire (yes they still burn )

Poink88, how long does it take typically...guestimate?

Fore wrote:Poink88, how long does it take typically...guestimate?

As Kev posted...when it is dull red. Time depends on your fire's intensity.

Poink88 wrote:

Fore wrote:Poink88, how long does it take typically...guestimate?

As Kev posted...when it is dull red. Time depends on your fire's intensity.

and how thick the wire is, and how much you are doing.

Are you anealing copper wire now Dario?, I guess i'm lazy but i buy mine ready done and in exact diameters that are useful - a kilo of each size lasts me one to two years and i wire quite a few conifer branches ! . (I woudnt even know what sort of electic cable held the really useful sizes of 2-4mm dia) a few other copper realated bits - dont tie trees into pots with it as the roots can be killed off near the wire as it ages, always use copper for guy wires as aluminium stretches under tension and aluminium is far better on deciduous trees or delicate conifers as it marks bark less and is easier to cut off.

cheers Marcus

marcus watts wrote:
Are you anealing copper wire now Dario?

Marcus, In my past life I did some annealing and tempering...mostly steel LOL.

For bonsai...I just use aluminum...cheap and easier for a newbie like me.

Both copper oxides (Cu2O = red and CuO = black) present mild to moderate health risks. CuO is listed as causing several issues, particularly when ingested. Therefore, I would either not anneal it in the BBQ or clean the BBQ well after annealing and before use for food. Since this is the major oxide on the surface of annealed wire I would suggest washing your hands after an extensive wiring session, particularly if they are dirty and it is not pine sap. However, the risks for most people are not so severe that one must wear gloves or take similar precautions.

The biggest problem in home annealing of copper is getting the wire uniformly annealed. Annealing requires a combination of time and temperature. Poorly annealed wire has hard spots where the wire was not hot enough for a long enough time. It is probably better to err on the side of a little long and/or hot than short and cool. If you leave the wire in the fire too long it will become thinner as the surface is converted from copper to copper oxide.

There is no need to quench in water as others have stated, but doing so tends to thermally shock the surface oxide layer which will normally end up in the bottom of the water bucket. Don't dump that water in the creek or storm sewers since copper compounds will kill roots and fish.

Here is a good article about annealing copper wire for Bonsai:

http://www.evergreengardenworks.com/copperwi.htm

I've found that many home annealed rolls have either hard spots that didn't get hot enough, or melted blobs where it overheated. You really don't want to find this while wiring your tree or oops that branch is broken. I'm sure if you're careful by putting it in a fire and watching the color closely, you can get good results. A better way is if you have a kiln, heat it up to the right temp and let it stay there for about 10 minutes, then quench. Marty's right, quenching will get rid of most of the oxidation and make it look uniform.

I'm glad you joined the conversation Marty! I don't think I'll use the BBQ then. Sounds too risky. Evergreen Garden Works article was very informative. But maybe it should be updated to discuss the oxides given off in the process. Esp. using something where one cooks.

I'll just try a blow torch for fun to see if it works. If not, I'll just keep buying it from Mr. Adams

Chris

Marty Weiser wrote:Both copper oxides (Cu2O = red and CuO = black) present mild to moderate health risks. CuO is listed as causing several issues, particularly when ingested. Therefore, I would either not anneal it in the BBQ or clean the BBQ well after annealing and before use for food. Since this is the major oxide on the surface of annealed wire I would suggest washing your hands after an extensive wiring session, particularly if they are dirty and it is not pine sap. However, the risks for most people are not so severe that one must wear gloves or take similar precautions.

The biggest problem in home annealing of copper is getting the wire uniformly annealed. Annealing requires a combination of time and temperature. Poorly annealed wire has hard spots where the wire was not hot enough for a long enough time. It is probably better to err on the side of a little long and/or hot than short and cool. If you leave the wire in the fire too long it will become thinner as the surface is converted from copper to copper oxide.

There is no need to quench in water as others have stated, but doing so tends to thermally shock the surface oxide layer which will normally end up in the bottom of the water bucket. Don't dump that water in the creek or storm sewers since copper compounds will kill roots and fish.