Plasma Piece: A Lot of Grinding

I went in to this homework believing it would be the quickest one to do, I was just going to cut out a diamond with a shape I’d make up on illustrator, angle grind it, and then coat it with lacquer or clear gloss cover (spray can). And for the most part, things worked out as expected. Except grinding the pice, there was a lot of grinding.

Step 1: Designing shape

The first thing to do for the homework was to create a unique shape to cut out using the plasma cutter, the only constraints being that we had to use the diamond file on canvas and we could not scale it. So I started by playing looking online for simple shapes (the plasma cutter isn’t very precise) to get inspiration, but ultimately just played around with tools in Illustrator until a cool shape appeared. This was done pretty quickly and I soon had three options to pick from, I chose the one that kinda looks like a stingray.

Step 2: Cutting

Now with my shape ready it was time to cut out the piece. I got help from a lab assistant to cut out two pieces. We used a sheet of metal that other had used for their homework as well. I should have checked what kind of metal it was because it turned out to be stainless steel, which is not magnetic and therefore I couldn’t use the magnetic table thing in the work shop, and would make it much harder to angle grind.

Step 3: Post Processing

As I mentioned before, I believed post processing would be relatively quick, as I would just angle grind the piece and coat it with something transparent like lacquer (my dad is a welder who likes to make furniture and art using metal, and will often give this kind of finish to his things). So I took my pieces outside and held them in one hand while using the other to control the angle grinder (don’t do this at home kids, it gets hot). One side of each piece came out nicely, but the other side seemed to have some sort of plastic coating as it started to peel off and burn away, but left the metal stained and black. I was unable to remove this since I could not keep the piece steady enough using my hands alone.

It wasn’t until a week later that I thought of clamping the piece to the metal railing outside and then angle grinding without worrying about the heat. The plastic coating finally came off and the angle ground finish looked nice.

However, I thought about improving the look of the pieces by using a different angle grinder in the work shop. So I spent the next hour just testing to see how my pieces would look like with different grinders. Ultimately I had to angle grind them the same way again to get the same finish back, except it also left a brownish coloring that was hard to see in the dark. This meant I had to angle grind one more time the next day while the sun was still out.

Step 4: Coating

Finally it was time to coat the pieces, I used clear gloss spray on the front of them and left them to dry for about 20min. Then I made a last minute decision to spray the back with a gloss black and left them to dry another 30min. At last, the pieces were done.

Estimated Cost:

Materials:

  • Stainless steel sheet: $4 (Grainger Industrial Supply)
  • Black Spray paint: $5 (Krylon, Lowe’s)
  • Clear gloss spray: $9 (Hobby Lobby)

Machine time:

  • Plasma Cutter: $22.5 (at 135 per hour, HercRentals)
  • Angle grinder: Angle Grinder:  $20 (Wal Mart, only considering hand angle grinder since it’s what I ended up using)

Designing:

  • Adobe Illustrator: $20 (monthly rate)
  • Making 2D model: $10 (at $10 per hour)

Labor:

  • Me: $20 (at $10/hr)
  • Someone who knows what they’re doing: $10 (at $10/hr)

Total cost: $120.5 for both pieces.

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