Crafting Durable Crucibles: An Updated Guide to Silicon Carbide and Sodium Silicate
0:00 Introduction: An updated version of the crucible-making segment from a previous microwave metal melting video is shown.
0:12 Materials Needed: Silicon carbide (fine, medium, or a mix of coarse and fine grit) and sodium silicate (water glass) are required. The suggested ratio is 8-10% sodium silicate by weight.
0:37 Mixing and Filling: The silicon carbide and sodium silicate mixture is added step-by-step into a mold (glass or 3D printed) and pressed down firmly.
0:50 Shaping the Crucible: Tools such as wooden sticks or 3D-printed tools can be used for pressing and shaping the crucible.
1:14 Microwave Curing: The crucible is placed on a ceramic fiber sheet and microwaved until the glass cracks (ice cube can be used to accelerate cracking but be careful to not overdo it).
1:48 Finishing: Sanding tools (files, sandpaper) are used to refine the shape of the crucible after removing it from the cracked glass.
2:05 Pre-Heating: The crucible should be heated in a metal melting chamber before its first use.
2:24 Hardening (Optional): Hardening makes the crucible stronger and less prone to cracking. Whether it's needed depends on the crucible's shape, thickness, height, and intended use. Hardening naturally happens when used with high melting point metals or fluxes.
3:20 3D Printed Molds: 3D-printed molds (available on printables for old molds, Patreon for new) can be used. New molds offer different sizes and thicknesses.
4:10 Mold Assembly: A lid (printed in soft filament is recommended), M5 screw with a hook, and binder clips are used to assemble the 3D-printed mold.
5:06 Pressing Tools: Custom press tools with a handle increase pressing efficiency. Tool for adding air also exists.
6:56 Freezing: After filling the 3D printed molds, freeze for at least 2 hours to help unmold the crucible
7:40 Hardening Process: The crucible can be hardened by wrapping it in ceramic fiber, securing it with rubber bands, and microwaving until it glows red. Once cooled, the ceramic fiber is scraped off (wear a respirator).
8:55 Downsides of Ceramic Fiber: Working with ceramic fiber is messy and requires protective gear (respirator, gloves).
9:55 Alternative Hardening Method: Using ceramic fiber kiln paper (for glass fusing) glued to the crucible with school glue is a preferred method.
10:30 Ceramic Fiber Kiln Paper Method the user is still advised to wear gloves.
11:01 Heating with Kiln Paper: The crucible with kiln paper must be heated well until the paper disappears or fuses with the silicon carbide.
11:43 Benefits of Kiln Paper: This method is better, cheaper, and avoids the downsides of loose ceramic fiber, but works best with smaller crucibles.