Charlie's Casting
My Monogramed Pewter Cast One Piece Multitool
My Multitool Design
I designed a one piece multitool featuring a bottle opener, four overlapping wrench sizes (1/4”, 5/16”, 3/8”, 7/16”), and a fifth wrench (3/16”) that doubles as a keychain loop. The part is 4” long, 1/4” tall, and 1/2” wide. Additionally, I engraved my initials in the center of the tool. I have always been a fan of multitools, and although I was well aware that pewter would not be an ideal material, I was eager to produce a proof of concept for my own design.
Casting Attempt #1
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Casting Attempt #1 Summary
Before casting with Pewter, we tested our molds with silicon. After 3D printing my multitool design, constructing an open face box in which to pour the mold, attaching a sprue (hot glue rod) and a vent (3D printing filament) to the base of the box and the 3D printed tool, and spraying the inside of the box with mold release, I mixed parts A & B of the casting mold and poured until the tool was submerged. The mold appeared to work OK after cutting to remove the 3D printed tool, sprue, and vent. However, upon casting with silicon, the mold left much to be desired.
Casting Attempt #2
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Casting Attempt #2 Summary
Having learned from my first attempt, I decided to use a simpler open face design. This way, the pewter would be able to reach the small nooks and crannies of the design more easily and the mold would not have a parting line. Still, post processing was required. After scraping excess pewter off of a few corners, I sanded all sides with the belt sander and again by hand with 600 grit sand paper. The pewter struggled to fill my initials etched into the front of the multitool, but after sanding, they were still adequately visible. Pouring the molten pewter into the mold was difficult and took three attempts to properly fill. I had to balance the speed of my pour yet still fill the smaller sections of the mold. My final product still has an unfilled border to the edge of the wrench section, but I am pleased with how it turned out overall.
The Final Result
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Takeaways
I gained valuable exposure to the casting process and experienced firsthand challenges with mold design and pouring. For my specific design: a multitool, a better material and manufacturing method would be CNC milled aluminum. Pewter is neither hard nor durable enough to be used in tools, and a CNC would machine my relatively simple design with ease. Nonetheless, this was a productive design challenge, and I certainly see how casting can be the most cost- and time-efficient manufacturing method for certain parts.