If nothing else, this assignment increased my respect for every post processed metal piece that we come across in our daily life.
My initial intention was to create something like a Christmas tree ornament with a hole at the top to thread a ribbon and a striated post processing effect. Instead, I ended with an almost symmetrical ice cream like shape with my name on it.
Using one of the shop reference pieces, Asma and I picked a 50 inches/minute feed rate to cut our steel stock. After getting started on the plasma cutter, the first pivot from this idea was to loose the hole as it was too small for the plasma cutter to effectively cut. Other than that everything was smooth-ish cutting barring having to go “fishing” in the plasma cutter bath to find one of my four cut pieces. I would highly recommend against using your bare hands in the future.
Once I had my pieces, I had to remove the heavy slag that was mostly present on one side of each piece. I used a large angle grinder to remove the majority of the slag and then a smaller one to remove the rust and get to a uniform state before the next post processing steps. We learned after the fact that the fan that helps blow the slag off during the cut was not working properly resulting in heavier than normal slag.
To smooth the edges and add a shine to the finish, I polished my pieces next both front and back . While I was exceptionally careful to not injure myself, I did manage to launch one of my pieces into the ground where the tip got bent. I tried to straighten it out with clamps and a hammer but ended up with more defects. Thankfully I had backups!
After burnishing, I tried vinyl cutting to create a stencil before sandblasting. While cutting the stencil was easy, placing it was much harder. Because I spelled out my name, I had to place the middle of the As and Rs. Unfortunately, during sand blasting the first A on one piece and the last A on the other came off. So to make my pieces uniform, I removed the remaining A centers. The sandblasting was very easy and managed to cover some areas where the angle grinder had left deeper marks. The final step was to peel off the vinyl sticker and while it mostly protected the area underneath there are a couple spots where the sandblasting made it under the covered area. In the future, I would try to be more careful with placing the vinyl and ensuring it stuck well.
Cost Estimate: Materials: Stainless Steel - 1 sheet (24" x 36") = $14.48 Vinyl - 1 roll (12" x 48") = $5.99 Labor: 2 hrs layout, setup, and cutting 2 hrs grinding, burnishing, vinyl cutting, and sandblasting 4hr X $7.25/hr = $29 Equipment: 1 day plasma cutter rental = $95 1 day sand blaster rental = $33 1 hr Cricut rental = $15 1 hr access to maker space with other equipment = $15 Total = $207.47
