The Goal:

This week, the goal was to work on plasma cutting and post-processing techniques on the metal to make it look presentable as a finished object. As we were all aiming to choose different states to make a complete map, I chose the state of Idaho. I did not have any particular reason for this choice, however, I do think it has a distinct and interesting shape.

Step 1: Plasma Cutting

   

We decided to try cutting the shapes from the ¼ inch aluminum metal sheet. From the line test and from the cut displayed in class, we decided that the optimal feed rate was 70. These settings worked out well with a clean cut and minimal dross. The dry run feature worked really well to test if there was enough space between other cut outs.

   

Overall, using the Torchmate software and the plasma cutter was pretty easy to use and did not take too long to execute the cut.    

   

Step 2: Filing off the dross

Right after plasma cutting the Idahos looked like this:

   

So it was important to use a file to get rid of the rough edges and the bumps to smooth things over. This left some scratches on surface but made the object much smoother and presentable.

   

Step 3: Refining with Sandpaper and the Sandblaster

To smooth the scratches, I tried using rough sandpaper and then a finer one to make the shape smoother and get rid of stains that were on the surface of the metal. Overall, this revealed a pretty polished surface, but I was not very happy with how it looked as you could see streaks from the sanding along the surface and it would need much more sanding and polishing to be completely smooth. Then, I decided to try out the sandblaster and got a different surface that was matte and very even.

   

Step 4: Vinyl Cutting a Sticker

Using the Summa vinyl cutter and accompanying software I tried to cut a vinyl sticker to stencil on the Idahos. I decided to cut out the White Western Pine tree which is the state tree of Idaho.

The process was similar to the laser cutter and plasma cutter where I used illustrator to create the shapes and placed it into the program and printed. I ended up using the positive sticker for one state and the negative sticker for other.

Step 5: Spray Painting

I spray painted both with silver spray paint and then dabbed at them to give the speckled effect with the metallic silver on the sandblasted surface.

After a day I checked back and saw that it turned out pretty well although not all the edges of the tree were clean. Both the negative and positive version looked really good and I thought I would apply a clear coat to make them smooth.

However, when I applied a transparent gloss coat to the surface, a gust of wind blew the whole newspaper over along with a bunch of dirt and ruined one of the states. I will try to process the ruined Idaho with a similar speckled silver effect, and try another vinyl sticker if I can get that done in time.

Final Results and Conclusion

Overall, I think that plasma cutting and post processing was a rewarding experience. The most compelling part was thinking of all the different ways to finish the metal. Here is what I ended up with:

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I like how the final Idaho turned out with the subtle differences in silver and the texture on the state. In the end, the plasma cutter turned out to be the easiest part and I learnt a lot about how to use many other tools like the files, sandpaper, sandblaster, and the vinyl cutter. Additionally, I think that it would be interesting to see how these tools can be applied to other materials besides metal in the future.