Copper Wire Preparation

[Mac In Oak Ridge]

I have heard it asked before about how to prepare copper wire for use in bonsai. I offer this tutorial of my method. I'll post it in two sections. This one of converting from wire as purchased to rolls of wire ready to anneal in a fire. The second issue in a day or two showing the annealing process.

First series of photos is of what you need to do this. Rolls of copper wire. You see four rolls of 14 Ga., each roll ca. 20 ft. long. Four rolls of 18 GA. each roll ca. 50 ft. long. One roll of 6 Ga. I don't remember how long the roll is but it is ca. 12" in diameter and weighs around 20 lbs.

I purchase the wire on ebay, just do a search for "bare copper wire" and you'll find an ample supply. Don't take the first price you run across.


You need a form to roll the wire around that is the diameter that you want your finished roll of wire to be. I use a small cake can. Note that there is holes drilled in the side, 2 of them. The holes is a place to hook the wire when starting the roll. Cake cans like this can be bought at hobby shops. This one is 5 1/2" in diameter. And importantly there is not a ridge on the end that the lid goes on. It is smooth all the way to the edge. If the can maker puts a ridge on the can where the lid goes you have a great deal of trouble sliding the finished roll off.

And you need some fine copper wire to bind the rolls together when you are handling them in the fire. Until the copper is annealed it is somewhat springy and you can end up with something that looks like a kids slinky toy if it gets away from you.


I put a roll of wire on a screwdriver sticking up in a vise to hold it while unwinding on to form. Bend a hook on the end of the wire and hook into one of the holes in the cake can. That holds the end as you wind the wire off the spool it was purchased on.

 

[Mac In Oak Ridge]

Once the end is hooked wind the wire around the form. Always keep a hand and finger on the wire where it is coming onto the form. That end gets loose on you and you can end up with a mess.

Once you have the amount of wire you want on the form then use the fine pieces of wire to bind the roll together. I put a small awl under the wire to make a path to insert the fine wire. I twist the fine wire tight, putting one at the end of the wire, turn the end up so it can't slide out from under the binding.


I put two binding wires on small wire, 180° apart, and three, 120° apart, on wire that is 12 ga. and above. This is what you end up with.



At this point you remove the lid from the cake can, take a screwdriver and straighten out the hook through the hole in the can and slide the wire roll off. Always work with the lid in place until you are ready to slide the finished roll off, it keeps the round can from deforming.

 

[Mac In Oak Ridge]

And your finished product looks like this.



In a day or two I'll anneal the wire in a fire and do a step by step through that process.

 

[pwk5017]

Heard about DIY annealing for a long time. I look forward to seeing your process and finding out if its possible/worth it to anneal your own. First off, do you use a kiln to anneal? Second, if you dont use a kiln, do you achieve a high quality finished product? aka, no hard spots or brittleness.

 

[yenling83]

I'm looking forward to part 2! Thanks!

 

[lordy]

I dont buy coils of wire, since my son-in-law happens to be an electrician. But I wonder why go to all the trouble to uncoil and recoil around the cake can when you could simply cut and remove the plastic spool it comes on?
I put my raw coils on a grill until it is red hot, then turn off the heat (gas grill). Works fine for me.

 

[Mac In Oak Ridge]

I dont buy coils of wire, since my son-in-law happens to be an electrician. But I wonder why go to all the trouble to uncoil and recoil around the cake can when you could simply cut and remove the plastic spool it comes on?
I put my raw coils on a grill until it is red hot, then turn off the heat (gas grill). Works fine for me.

The core of the plastic spools is about 1" in diameter and the OD about 2 1/4" (excepting the 6 Ga. wire). I don't want coils of wire that small to work with. Once annealed as soon as you start using the wire, straitening it out to wrap on a limb it starts to harden up again. By the time you would unwind all those small coils it would have lost it's softness. I find larger coils easier to work with.

 

[Mac In Oak Ridge]

Heard about DIY annealing for a long time. I look forward to seeing your process and finding out if its possible/worth it to anneal your own. First off, do you use a kiln to anneal? Second, if you dont use a kiln, do you achieve a high quality finished product? aka, no hard spots or brittleness.

I use a fire in the back yard. I don't use a kiln, yes I achieve a high quality finished product. No hard spots or brittleness. It isn't rocket science. When copper is heated to red hot it has reached the annealing temperature. As long as the entire coil reaches that point the entire coil is annealed.

 

[edprocoat]

I usually wrap my wire around an old can, like an old carrot can or one that is wide enough to match the diameter of the grates on my stove. I do not tie the coils, the copper once wrapped seems to hold fine for me, I slide it off the can then I place it on the stove and heat it until its red hot then pick it up with my pliers and drop it in the sink full of water. No hard or brittle spots and the wire is soft until bent. I like large coils too as they do not need bent out as much when wiring a branch.

ed

 

[Jaberwky17]

Only anneal in winter

I use an outdoor wood boiler to heat my rural home, which makes it pretty easy to anneal wire. I use electrical wire with plastic coating, and toss the whole thing in the boiler. The heat takes care of the wire jacket very quickly, and the post-annealing water dunk gets rid of the bits of jacket that might be left. I have run into a few spots that are brittle when wiring but to me it's worth it by not having to buy wire.

 

[Poink88]

Nice tutorial Mac! Thanks!

For now I just use aluminum...not the best but it works, reusable, can be re-bent, and cheap too! Maybe I'll try using copper when my trees (and I) are better.

 

[MACH5]

Nice tutorial Mac! Thanks!

For now I just use aluminum...not the best but it works, reusable, can be re-bent, and cheap too! Maybe I'll try using copper when my trees (and I) are better.

Not to get sidetracked, but actually aluminum is a far better choice for most deciduous applications IMO.