Colorful Copper on Useless Dice

I made two useless steel dice.

Why?

Well, why not?

Actually, I had several reasons to make these dice. The main reason is that I recently discovered that copper can get quite colorful when it is heated and I wanted to experiment with that. The second reason is that I like welding, but since I also like lots of other things, my welding skills could use some practice. And the third reason is that I wanted to make something where the number 1000 plays a role, because this is an entry in the 1000th contest of Instructables.

Why are these dice useless?

They are large and made of steel and if you roll these dice on your beautiful dining table, you probably get dents or scratches. Feel free to try it anyway, but do not tell me that I did not warn you.

The dice are also useless for nearly every game, because they always give 1000 as a result. That would be great for a game where you need to get two equal numbers on the dice, but with my dice all six sides are still different, as I have: 1000, 2x500, 10^3, the Roman number M, the square root of one million and the Chinese character for one thousand.

Some weeks ago I was curious what would happen if I used a copper rod instead of a steel rod during TIG welding, so I tried it. At first it seemed like I got burned black copper, but with a wire brush and some brushing the shiny copper came back and I immediately liked it. So I have been experimenting in the past weeks and now I like it even more. I already knew that it is possible to get really colorful welds with stainless steel and I tried that before, but I think using copper to get lots of colors requires less skills than using stainless steel.

So let me share with you what I did in the next steps.

Three remarks up front:

1. This project is only about decoration and colors. Welding copper to steel will not result in a strong weld.

2. Please forgive me that my welds are not as beautiful as the welds of some skilled welders. This Instructable is not about getting straight and perfect welds, but it is about getting colorful copper on steel.

3. I have not seen other people use copper to get colorful welding beads on steel. If you have seen it somewhere before or if you tried it yourself, please share it with me, because I would love to see what other people can make with this method.

Equipment:

TIG welding machine

Angle grinder with cutting disc and wire wheel

Dremel

Knife

File

Wire brush

Ruler and marker

Sand paper

Materials:

Steel (thickness is not that important, but I used 2 mm thick sheet metal and my dice are 8x8x8 cm.)

Copper wire, the solid core type that is used in electric wiring in your house.

Argon as shielding gas

Acetone

From some electrical projects in the house I had left over pieces of copper wire in short lengths. They are ideal for this project. If you do not have any left over pieces, you can buy some copper wire. I used in total approximately 5 meters (17 feet) of copper wire.

The two most common sizes of copper wire are 1.5 mm2 and 2.5 mm2. I tried both sizes and did not notice a lot of difference, so you can use either one.

Of course you first have to remove the plastic insulation around the copper wire. I use a knife for or that. Just try to keep the sharp side of the knife slightly tilted towards the copper core and cut the plastic. That works quite well. It took me about half a minute to strip one meter of copper wire.

During my trials I tried first cutting the squares versus first adding the copper and then cutting the squares. Cutting first worked best because that way it is easier to keep the temperature in the steel down. If the temperature of the steel rizes, the copper reacts differently and the steel does not stay straight. By cutting the steel in smaller pieces first, the heat from one piece does not influence or heat up the other piece.

My cubes are 8x8x8 cm, so I cut a total of 12 pieces, as each cube has 6 sides. I used steel of 2 mm thick, but you can also use thicker steel. I do not recommend to use thinner steel, because then it becomes more difficult to weld the sides together to form the cubes.

I used an angle grinder to cut the squares and a file and sandpaper to remove the sharp edges after cutting.

I used a marker to write the numbers on the steel. Then I used a dremel to trace the numbers, so the steel gets scratched where the numbers have to come. With acetone I removed the black ink and any other dirt from the steel, because for TIG welding the metal has to be really clean. The result is a clean piece of steel with scratched numbers that are visible through the welding helmet while welding, so you know where the copper should go.

Remark: Technically I did not weld the copper to the steel. For welding both the copper and the steel should melt, but I only melted the copper, so actually it is brazing instead of welding. But since I used a TIG welding machine, I will still use the word "welding" in this Instructable.

Using copper as a welding rod works quite similar as welding with a steel welding rod. I assume you know how to TIG weld with steel before you will try to use copper, so I will only describe what is different:

• I used quite a low current as setting, only 60 Amperes. The idea is that the copper will melt, but the steel itself will not melt, so you need less heat than you would use for welding steel.
• A steel welding rod is straight, but your copper wire might have some curves. Make your copper wire as straight as possible. That makes adding the filler rod easier.
• When you weld the entire number on the same square without any cooling down time in between, you will notice that the copper will flow different when the steel gets hotter. That leads to differences in height in your welding beads. So when you see the copper beads getting wider and lower, it is time to put this square aside to cool down and move on to the next one.
• Normally welding goes along a straight edge or pipe so "writing" numbers is probably something you have not done a lot with a TIG welding machine. I recommend to practise a bit on a scrap piece to get some feeling for "writing" numbers while welding.

As shielding gas I used 100% argon at a similar flowrate as I would use for welding steel.

I used the ground clamp from the welding machine and a second clamp to keep the steel flat on my welding table. Then I welded part of the number on one square, put it aside to cool down a bit and moved on to weld part of the next number on the next square. I used that method for 9 of my squares and they stayed pretty straight. I also welded three numbers on one piece of steel before cutting the squares. You can see on the third photo that the ground clamp is holding the steel down, but left of the number 10^3 the steel is no longer flat. That makes it more difficult to make the cubes later, so cut all your squares before welding.

When I finished welding all the numbers on the steel, the steel had changed color by the heat as you can see on the first photo.

Use the wire brush to manually remove the discoloration from the steel. Do not use a grinder with a wire wheel, because that will scratch the copper and copper dust will be forced into the steel next to your numbers.

Probably you will remove all the color from your copper too, but that is no problem at all. You can bring the color back to the copper, by heating the copper slightly again. I recommend that you do not bring the color back right now, but that you first assemble the cubes.

On the second and third photo you can see that the color on the copper came back, but there is also again a blue color present in the steel. That was because I ignited the TIG torch and kept it a few seconds on the same point above the copper, so the copper just started to melt again. That is not what we want, so after some testing I found out that it is best to ignite the TIG torch above the copper and immediately move the torch over the copper with the speed you would use when writing normally with a pen. That way the copper will change color but it will not melt and the color of the steel will not really change. We will use that method to bring back the color on the copper after assembling, welding and cleaning the cube.

Use a welding magnet to hold the sides in the correct position and add tag welds.

I used steel welding rod for the tag welds and for putting the cubes together.

I first tried to use stainless steel and then I tried to use copper to assemble the cubes, but both methods did not work for me. The stainless steel got the black burnt-sugar look you get from poor argon shielding. With copper the problem seemed to be that it did not work for a vertical weld. Or maybe the problem is just a lack of skills from my side.

Anyway I did not really mind that I had to use steel to weld the sides of the cubes. It was good to practice welding those joints. I did not burn a hole in the sides and the result is not too bad, although it could be better.

Now you have to choose what you like best. One of my cubes has shiny copper and a blue and orange sqare around each number, while the second cube has numbers in colorful copper, but no blue and orange squares. It is also possible to get colorful copper and blue and orange squares. Just choose what you like best.

The Chinese character on the photos above has the shiny copper with the blue and orange square. I brushed the copper and steel clean (as in the previous steps) and welded the sides of that cube. That heat resulted in the blue and orange square around the Chinese character. Then I used the wire wheel on the angle grinder to clean the steel welded joints at the sides, while carefully avoiding the blue and orange area. That way I got a nice square around my number and I did not apply any heat to color the copper again, so the number has a kind of golden color.

On the second photo you see the number 1000. After welding that cube I used the wire wheel to clean the sides and the wire brush to remove all the color from the number. Be aware that I did not touch the copper with the wire wheel as that would scratch the copper. It is easy to remember: whire wheel only for steel.

When the cube is cleaned it is time to get the color back on the copper. Ignite the TIG torch above the copper and move it rather quick over the copper with the speed you would use for normal writing with a pen. The copper should not melt at all and the steel should not change color. The color of the copper comes a few seconds after you applied the heat. If you do not like the result you could use the wire brush to remove the color again, wait for the steel to cool down and try again.

Enjoy the results and think about where you can use this technique in other projects.

I would love to see anything you made with this method.