How to Make Bronze Wire (the old fashion way)
January 22 2015
Occasionally I get in one of those moods where I must experience the process known as "making wire." This involves hours of repetitive tasks. It also attracts puzzled looks and curiosity from my studio mates who can’t figure out why I would do this when wire is readily available at supply stores. Normally, I would agree with the sentiment; however, once in a while, I have a need to “meditate”, and this allows me to do that. And I quite enjoy it. Something about the metal transforming from a granule form to an ingot and finally to a wire… very zen…..
So with the assistance from the studio supervisor and a master metalsmith, Jose, this is how I spent my last Saturday.
1. Materials (bronze grains in a crucible, torch, and an ingot mold.
2. On the left I'm putting the torch to the crucible with the bronze granules until they are melted. On the right, Jose is showing me how to pour the molten metal into the heated mold. I’ve done this a couple of times before, but I always appreciate the refresher especially with a big torch.
3. Right out of the mold, this is what it looks like. To fill the entire length of the mold, it would have required a larger amount of bronze. I didn’t need that much, so this is what I got. It’s about 2 inches in length and ½ inch in thickness.
4. This is a rolling mill. The ingot now has to be rolled through this over and over until it is thin enough to be drawn. Never run wet metal through it, it will rust. You tighten the rollers in small increments as the metal is shaped and thinned. As you can see in the photo on the right, the rollers have graduated grooves. I had to roll the ingot through each groove until the metal was small enough to go through the draw plate.
5. Rolling the ingot through the mill is not a simple process because between the rolls, it has to be annealed (heated) to make it more pliable. So after about every 6 “rolls” or so, I had to torch it. The largest groove takes the longest, because for the ingot to fit through it when the rollers meet, it takes many, many “rolls” and annealing. Below are the various stages of the metal during the process. The differences in color have to do with whether I cleaned it or not. The pink color comes from copper plating when put in the pickle (acid) pot. It will be cleaned off at the end to get the bronze color back.
6. When the wire got too long, I cut it in half, and only used one of the pieces to continue. When that wire got too long, I cut it in half and rolled only one of that. You can see the difference in thickness.
7. Once the wire gets thin enough, it can now go through the draw plate. The plate has graduated holes, and by drawing the wire through, it will shape it round. Again, the wire needs to be annealed so that it will be pliable, and it will be drawn over and over until you get the thinness you want.
8. Here is the final product. You can really see the size differences when it is next to the wires at previous stages. So the ingot (1/2” thick ) was transformed into a 1.02mm thin wire. It is now ready to be fashioned into jump rings or anything else to be incorporated into my work.