Annealing Copper Wire Finally and Need a Little Advice Pls

[August44]

I need to update this. For some reason I am not getting notifications of additions to this thread. I really appreciate all the input and ideas.
I used an electric kiln as mentioned above. The pottery studio guy in charge set the kiln up for 1150 F with a 15 minute hold. It was later in the evening and the pottery gig going on was going to end at 9 pm and that also was when the man in charge wanted to leave. Since this was the first time either of us had tried to anneal in a kiln, he was a bit hesitant about leaving and depending on the set hold to shut things down, so we shut it down when the temp was at 1100 F with no hold. then we left and i came back in the am and checked on the firing. All of the wire was on three shelves, and not using the bottom one. All the wire was black and I could see that a bit of the black chips, slag or whatever you call it was on each shelf and had also drifted down to the bottom of the kiln also. I started removing the wire shelves with the wire on them because as soon as you tried to move the wire, the flakes started falling down ever where, so had to be careful that it didn't get everywhere. I finally got all the wire in buckets trying not to disturb the wire to much. Then had to clean all of the shelves and vacuum the inside of the kiln. Took the wire home and put it in a solution of 1 gallon of white vinegar and one TLB of salt. Had to buy 6 gallons of the vinegar so I could fill up a 5 gallon bucket and soak most of the wire at one time verses a little bucket and a lot of time waiting and then another batch, and another batch etc. The directions said 30 minutes to 1 hr would generally clean the wire up, but I found that it took about 2 1/2-3 hrs for the wire to be clean. I got it all cleaned off and it looked very good IMO. When using a kiln it is about impossible to open up the kiln and quench the wire when the kiln is indoors and with a temp 1100-1300 F rolling out the open door. I am getting the opinion that quenching is a must.

I had yet to check the wire on the success of the annealing. Big surprise when I did. As you might remember, I was annealing, 14 gauge, some 13 gauge, some 12 gauge, some 11 gauge, and some 6 gauge. The 12, 13 and 14 gauge are ok. The 10 and the 6 need to be re-fired. I am going to guess that taking it only to 1100 F with no hold was a big part of the problem, but maybe 1200-1300 with a 15-20 minute hold might have worked better for everything?? I know someone recommended that I do the heavier wires (6) separately, but that was starting up the kiln again for just a few rolls of 6. It really ended up being a big job considering time to unscramble all the old wire from the metal joint, wrap it all in coils, fire it, clean it, clean up the kiln shelves and the kiln itself. Your thoughts would be appreciated.

 

[August44]

August,
The way that I’ve been enjoying an old grill at 600 degrees and holding that temp for 20 minutes.
Afterword I put it in a bucket for 10 minutes or so to take off the scale.

Hey Paul thanks for the reply and good to hear from you. My gas oven and BBQ will only go to 550 F. I tried both and even smaller wire was not anneal at that temp.

 

[JeffS73]

All in all sounds like it went well for a first go. Its a lot of clean up though isn't it? You can use less acid and let it sit overnight. Dried citric acid is cheap and can be added to hot water which speeds the process up better than stronger acid.
Getting rid of the liquid is ls less easy.
From the copper book I read, quenching is absolutely NOT necessary. Just faster cleaning.

 

[Brian Van Fleet]

Your thoughts would be appreciated.

I think you might have figured out firsthand why most people just order it.

Copper training wire

 

[August44]

I think you might have figured out firsthand why most people just order it.

Copper training wire

That's funny and totally correct Brian It was more of a challenge thing for me. Now I can say I have done it.
By the way, do you know how most commercial annealed wire people heat their product?

 

[August44]

That's funny and totally correct Brian It was more of a challenge thing for me. Now I can say I have done it.
By the way, do you know how most commercial annealed wire people heat their product?

Why'd ask that question anyway? I know ur answer...you don't know AND you don't want to know!

 

[August44]

I had a mixture of white vinegar and salt (1 cup salt to 1 Gallon of white vinegar or1 TLB salt to 1 cup of white vinegar) to remove the slag. after 1.5-2 hrs. all slag was loose and came right off with the hose. Will this solution keep in a closed bucket does anyone know?

 

[RJG2]

I had a mixture of white vinegar and salt (1 cup salt to 1 Gallon of white vinegar or1 TLB salt to 1 cup of white vinegar) to remove the slag. after 1.5-2 hrs. all slag was loose and came right off with the hose. Will this solution keep in a closed bucket does anyone know?

It should - I know restaurants get their pickles in five gallon buckets - pretty much the same thing!

(Yes, I once had my wife get me a five gallon bucket of pickles when she was in the restaurant industry...)

 

[Attmos]

So..... Is 12-2 or 14-2 wire not strong enough to train a tree? I ran residential wire for a long time and even soft copper is pretty stiff, work hardening doesn't even affect its strength much. It is basically the same as annealed copper. Soft, pliable, but strong.. especially when coiled.

Why the need to anneal copper wire?

 

[leatherback]

Why the need to anneal copper wire?

to make it softer. Non-annealed copper will just bruise the branches and make it hard to put on

 

[August44]

So..... Is 12-2 or 14-2 wire not strong enough to train a tree? I ran residential wire for a long time and even soft copper is pretty stiff, work hardening doesn't even affect its strength much. It is basically the same as annealed copper. Soft, pliable, but strong.. especially when coiled.

Why the need to anneal copper wire?

Have you ever tried to wire a tree with 4 or 6 gauge copper that's not annealed?

 

[August44]

I was wiring some larger trees yesterday and ran out of 6 gauge so grabbed some brand new 6 gauge that I had purchased a year or so ago. It's from Japan and I am sure it was a steal when I bought it . Take a look at the pictures. Does that look like it was ever annealed to you? Felt and looked like it was never annealed at all and shows no evidence that it ever was. No discolorations on the wire anywhere. Maybe it had been around long enough that it lost the initial anneal? No clue but I will re-do it with the other wire that didn't take on the first go-around.

 

[ShadyStump]

Suppositions based on my experience with annealing copper wire on a fire at home.

Rarely are you getting pure copper. There are different grades of copper wire made of different alloys with different characteristics. One may be made to stay soft and not work harden easily. I imagine the stuff used for electrical wiring is engineered for a compromise between this and conductivity, so that you're less likely to get breakage and shorts in your wiring during installation.

The temperature you bring your wire too while annealing can directly effect it's softness and what it takes to harden it again. My personal observations show that lower temps yield material that's workable for a shorter time before hardening, and vis versa for higher temps. As mentioned before, composition may directly effect this.

The spottiness of coloration after annealing has as much to do with even heating and how the material recrystalizes as it does with contaminants. Most of us using repurposed wire are using something that likely has a coating of some sort applied, and in some cases matter from within the copper itself (remember that first part about alloys) may be burning off.
Annealing at home on a fire, I had luck placing the finished coils of wire in the oven on high for a while, and this seems to even out the coloring a little bit. This leads me to believe that when using a kiln a hold time and a very slow cool down will make a prettier end product, more like the commercial stuff. Pickling is to bring back the shine, which aesthetically I don't think is necessary, and is arguably distracting against the matte colors of the bark.

I have personally not seen much practical difference between quenching and not, though I tend not to because of the aforementioned heating/holding/cooling effects on coloration.

Again, all supposition from anecdotal observation. If anyone knows someone with experience in metallurgy, that's what we really need.

Something to remember about our homemade stuff vs the commercial stuff: they know literally everything about this, and have specialty equipment for it. Don't put yourself out trying to compete with that when virtually no one will ever notice or care about the difference.

 

[August44]

Suppositions based on my experience with annealing copper wire on a fire at home.

Rarely are you getting pure copper. There are different grades of copper wire made of different alloys with different characteristics. One may be made to stay soft and not work harden easily. I imagine the stuff used for electrical wiring is engineered for a compromise between this and conductivity, so that you're less likely to get breakage and shorts in your wiring during installation.

The temperature you bring your wire too while annealing can directly effect it's softness and what it takes to harden it again. My personal observations show that lower temps yield material that's workable for a shorter time before hardening, and vis versa for higher temps. As mentioned before, composition may directly effect this.

The spottiness of coloration after annealing has as much to do with even heating and how the material recrystalizes as it does with contaminants. Most of us using repurposed wire are using something that likely has a coating of some sort applied, and in some cases matter from within the copper itself (remember that first part about alloys) may be burning off.
Annealing at home on a fire, I had luck placing the finished coils of wire in the oven on high for a while, and this seems to even out the coloring a little bit. This leads me to believe that when using a kiln a hold time and a very slow cool down will make a prettier end product, more like the commercial stuff. Pickling is to bring back the shine, which aesthetically I don't think is necessary, and is arguably distracting against the matte colors of the bark.

I have personally not seen much practical difference between quenching and not, though I tend not to because of the aforementioned heating/holding/cooling effects on coloration.

Again, all supposition from anecdotal observation. If anyone knows someone with experience in metallurgy, that's what we really need.

Something to remember about our homemade stuff vs the commercial stuff: they know literally everything about this, and have specialty equipment for it. Don't put yourself out trying to compete with that when virtually no one will ever notice or care about the difference.

Thanks for the input. So for copper wire 18Gauge-4 gauge, what temp with a hold works best do you think. I also stacked rolls on top of each other and wonder if that should not be done, especially, with no hold.

 

[yashu]

Suppositions based on my experience with annealing copper wire on a fire at home.

Rarely are you getting pure copper. There are different grades of copper wire made of different alloys with different characteristics. One may be made to stay soft and not work harden easily. I imagine the stuff used for electrical wiring is engineered for a compromise between this and conductivity, so that you're less likely to get breakage and shorts in your wiring during installation.

The temperature you bring your wire too while annealing can directly effect it's softness and what it takes to harden it again. My personal observations show that lower temps yield material that's workable for a shorter time before hardening, and vis versa for higher temps. As mentioned before, composition may directly effect this.

The spottiness of coloration after annealing has as much to do with even heating and how the material recrystalizes as it does with contaminants. Most of us using repurposed wire are using something that likely has a coating of some sort applied, and in some cases matter from within the copper itself (remember that first part about alloys) may be burning off.
Annealing at home on a fire, I had luck placing the finished coils of wire in the oven on high for a while, and this seems to even out the coloring a little bit. This leads me to believe that when using a kiln a hold time and a very slow cool down will make a prettier end product, more like the commercial stuff. Pickling is to bring back the shine, which aesthetically I don't think is necessary, and is arguably distracting against the matte colors of the bark.

I have personally not seen much practical difference between quenching and not, though I tend not to because of the aforementioned heating/holding/cooling effects on coloration.

Again, all supposition from anecdotal observation. If anyone knows someone with experience in metallurgy, that's what we really need.

Something to remember about our homemade stuff vs the commercial stuff: they know literally everything about this, and have specialty equipment for it. Don't put yourself out trying to compete with that when virtually no one will ever notice or care about the difference.

I did a little bit of interweb digging on copper composition for electrical usage and I found that almost all was 99.9% pure. Small amounts of impurities can have a surprisingly significant impact on resistance. For example; “A small amount of impurity in copper can cause a large amount of hindrance, 0.05% of arsenic can cause a 15% hindrance in conductivity.” For most electrical wire ETP (electrolytic tough pitch) is the standard at 99.9% purity and for special applications where even higher conductivity is required “oxygen-free high conductivity" (OFHC) copper, which can be over 99.99% pure is used

So basically if you’re using repurposed electrical wire, composition is a non issue.

 

[Paradox]

I am getting the opinion that quenching is a must.

No quenching isnt a must, just makes it faster to be able to handle the wire after heating it

It really ended up being a big job considering time to unscramble all the old wire from the metal joint, wrap it all in coils, fire it, clean it, clean up the kiln shelves and the kiln itself.

Yup its alot of work which is why I did it only once. By the time I stripped the plastic coating off the wire (I wasnt going to burn that off in my in house fire place), which was a job in itself, coiled the wire, fired it and cooled it, I decided the time involved really didnt save my anything considering the cost of a roll. If I was paying myself, it was more money in time to do all the work. If the wire is free to you and you have a lot of time on your hands and enjoy the work of it all, then it might be worth it. I have other things Id rather do with my available time, like actually work on my trees.

Your thoughts would be appreciated.

See above

 

[alphaparrot]

Suppositions based on my experience with annealing copper wire on a fire at home.

Rarely are you getting pure copper. There are different grades of copper wire made of different alloys with different characteristics. One may be made to stay soft and not work harden easily. I imagine the stuff used for electrical wiring is engineered for a compromise between this and conductivity, so that you're less likely to get breakage and shorts in your wiring during installation.

The temperature you bring your wire too while annealing can directly effect it's softness and what it takes to harden it again. My personal observations show that lower temps yield material that's workable for a shorter time before hardening, and vis versa for higher temps. As mentioned before, composition may directly effect this.

The spottiness of coloration after annealing has as much to do with even heating and how the material recrystalizes as it does with contaminants. Most of us using repurposed wire are using something that likely has a coating of some sort applied, and in some cases matter from within the copper itself (remember that first part about alloys) may be burning off.
Annealing at home on a fire, I had luck placing the finished coils of wire in the oven on high for a while, and this seems to even out the coloring a little bit. This leads me to believe that when using a kiln a hold time and a very slow cool down will make a prettier end product, more like the commercial stuff. Pickling is to bring back the shine, which aesthetically I don't think is necessary, and is arguably distracting against the matte colors of the bark.

I have personally not seen much practical difference between quenching and not, though I tend not to because of the aforementioned heating/holding/cooling effects on coloration.

Again, all supposition from anecdotal observation. If anyone knows someone with experience in metallurgy, that's what we really need.

Something to remember about our homemade stuff vs the commercial stuff: they know literally everything about this, and have specialty equipment for it. Don't put yourself out trying to compete with that when virtually no one will ever notice or care about the difference.

Just to chime in on the question of discoloration when annealing, as someone who has worked with electroforming equipment to make jewelry (basically a relative of electroplating, to build up 1-2mm of copper on an object such as a leaf, branch, or pine cone using electricity, sulfuric acid, and conductive graphite paint). The discoloration isn't related at all to the level of impurities in the copper nor to the molecular processes happening in the core of the wire during heating and cooling; it's due to oxidation (patina). Bare, pure copper readily oxidizes, and will form oxides of different colors depending on ambient humidity, temperature, the presence of salts or acids, the presence of other strong oxidizers (like sulfur dioxide or hydrogen sulfide, ammonia, chlorine, etc), the roughness of the copper, etc. Some of the colors come from the oxide chemicals themselves, like blues, greens, and blacks, while others like reds and purples are related to iridescence and are due to the crystalline structures formed between atoms-thick layers of oxides. There is an art form called flame-painting in which copper is heated to or above annealment temperatures using a torch, to get different brilliant colors in patterns like brush-strokes. There is also a Japanese patination technique called hido in which the copper is heated until it glows yellow, and then quenched in water and borax, at which point it immediately oxidizes to a deep, brilliantly solid red color. You can get heat patination at lower temperatures too, though; try putting bare polished copper in your oven at 400F for an hour and see what it does (depending on smoothness, likely red, purple, or brass/gold).

Regardless of the effect of quenching on the tensile properties of the wire, the biggest effect it has is to stop the heat-driven oxidation process. Quenching in a pickling solution will strip any oxides that form as it cools. If the copper air-dries with acids present, though, it will quickly oxidize to green, so it's a good idea if you want a clean copper color to dip it in a solution of water and baking soda after pickling to neutralize the acid, and then dry the copper with a paper towel. It will still oxidize eventually, but not as quickly, and the thin layer that does form over time will serve to protect the wire from further degradation.

 

[ShadyStump]

I did a little bit of interweb digging on copper composition for electrical usage and I found that almost all was 99.9% pure. Small amounts of impurities can have a surprisingly significant impact on resistance. For example; “A small amount of impurity in copper can cause a large amount of hindrance, 0.05% of arsenic can cause a 15% hindrance in conductivity.” For most electrical wire ETP (electrolytic tough pitch) is the standard at 99.9% purity and for special applications where even higher conductivity is required “oxygen-free high conductivity" (OFHC) copper, which can be over 99.99% pure is used

So basically if you’re using repurposed electrical wire, composition is a non issue.

Just to chime in on the question of discoloration when annealing, as someone who has worked with electroforming equipment to make jewelry (basically a relative of electroplating, to build up 1-2mm of copper on an object such as a leaf, branch, or pine cone using electricity, sulfuric acid, and conductive graphite paint). The discoloration isn't related at all to the level of impurities in the copper nor to the molecular processes happening in the core of the wire during heating and cooling; it's due to oxidation (patina). Bare, pure copper readily oxidizes, and will form oxides of different colors depending on ambient humidity, temperature, the presence of salts or acids, the presence of other strong oxidizers (like sulfur dioxide or hydrogen sulfide, ammonia, chlorine, etc), the roughness of the copper, etc. Some of the colors come from the oxide chemicals themselves, like blues, greens, and blacks, while others like reds and purples are related to iridescence and are due to the crystalline structures formed between atoms-thick layers of oxides. There is an art form called flame-painting in which copper is heated to or above annealment temperatures using a torch, to get different brilliant colors in patterns like brush-strokes. There is also a Japanese patination technique called hido in which the copper is heated until it glows yellow, and then quenched in water and borax, at which point it immediately oxidizes to a deep, brilliantly solid red color. You can get heat patination at lower temperatures too, though; try putting bare polished copper in your oven at 400F for an hour and see what it does (depending on smoothness, likely red, purple, or brass/gold).

Regardless of the effect of quenching on the tensile properties of the wire, the biggest effect it has is to stop the heat-driven oxidation process. Quenching in a pickling solution will strip any oxides that form as it cools. If the copper air-dries with acids present, though, it will quickly oxidize to green, so it's a good idea if you want a clean copper color to dip it in a solution of water and baking soda after pickling to neutralize the acid, and then dry the copper with a paper towel. It will still oxidize eventually, but not as quickly, and the thin layer that does form over time will serve to protect the wire from further degradation.

Well then, consider us educated. Thanks for the info.

@August44, I really can't speak to exact temperatures or times. I didn't have anything that could measure those temps accurately at the time. I tried building a makeshift wood fired kiln once thinking it would get me a nice even heat, but I never got results that justified the effort. I think it was a matter of scale. Even heating is the goal, and I just couldn't do it without building something entirely unjustifiable for my resources. I wound up going with straight in the fire, flipping the coils now and then for even heating.
That said, I just tried to get the entire coil as uniformly red as possible. Holding it there ensures that that temperature goes throughout, not just the tips and outer layers of the coil. I did try going straight from the fire to the oven at 550 for about and hour, and noticed that the color was more uniform if not completely. I think @alphaparrot might have helped explain that.

Given what these two have thrown in the mix, I'd suggest a slow climb of an hour to something around 900 degrees F, and holding for an hour would be safe practice even on large batches. Should give you something hardens as worked for trees, uniform throughout.
Let me know, anyone, how this sounds.

 

[ralfish]

I did a little bit of interweb digging on copper composition for electrical usage and I found that almost all was 99.9% pure. Small amounts of impurities can have a surprisingly significant impact on resistance. For example; “A small amount of impurity in copper can cause a large amount of hindrance, 0.05% of arsenic can cause a 15% hindrance in conductivity.” For most electrical wire ETP (electrolytic tough pitch) is the standard at 99.9% purity and for special applications where even higher conductivity is required “oxygen-free high conductivity" (OFHC) copper, which can be over 99.99% pure is used

So basically if you’re using repurposed electrical wire, composition is a non issue.

I have a bunch of salvaged 0.10 (about 2.5 mm) copper wire that in its previous life served as electrical conductor hanging from glass insulators on top of power poles. Its old as I collected it in the 1980s from a ghost town in BC, my best guess early 1900s, based on the glass insulators instead of ceramic. It looks like regular copper wire but remains hard no matter my method of annealing (purple, dull red, bright red, soak no soak, quench, slow cool) Otherwise it behaves like normal 100% copper, but it would be interesting to find out just what the alloy actually is.

 

[August44]

What is the difference between soft copper wire and the normal copper wire for annealing. I see some wire for sale but some of it is labeled as soft copper. Just wondering.