TL;DR: Create a porcelain vase by casting liquid porcelain slip in a plaster mold, then firing it in a kiln at cone 6–10. This guide covers mold prep, pouring, cleanup, glazing, and firing for a durable, food-safe finish.
Step 1: Gather Materials and Prepare Your Workspace
You will need porcelain slip (pre-mixed casting clay), a two-part plaster mold, a bucket, a stirring stick, a sponge, a fettling knife, glaze, and a kiln. Work on a sturdy table covered with plastic. Ensure the mold is completely dry and at room temperature—moisture causes defects. Wear a dust mask when handling dry porcelain powder.
If you want to dig deeper, check out our guide on 10 Tips to Identify Antique Porcelain Vases: A Beginner’s Gu.
Step 2: Pour the Porcelain Slip
Stir the slip gently until smooth, then pour it steadily into the mold’s reservoir. Fill to the top and wait 10–20 minutes. The plaster absorbs water, forming a wall. For a 1/4-inch wall, test by pouring excess slip out when the rim looks firm. Tip: Keep the mold filled during waiting to avoid uneven thickness.
Step 3: Drain, Trim, and Release
Pour excess slip back into your bucket. Invert the mold and let it rest until the vase releases on its own—usually 30–60 minutes. Do not force it. Once free, use a fettling knife to smooth the seam line. Sponge the surface with a damp sponge to remove slip residue. Let the greenware air-dry for 24 hours.
Step 4: Bisque Fire and Glaze
Bisque fire your vase to cone 06 (about 1828°F). Let it cool slowly. Mix your glaze thoroughly, then dip or brush it evenly. Wipe the bottom foot clean to prevent kiln sticking. Fire again to cone 6 (2232°F) for a durable, waterproof finish. Tip: Test glaze on a small porcelain tile first.
FAQ
Q: Can I make a porcelain vase without a kiln?
A: No. Porcelain requires high-temperature firing to vitrify. Air-dry clay or polymer alternatives are not true porcelain.
Q: Why did my vase crack during firing?
A: Cracks usually come from uneven wall thickness, trapped moisture, or firing too fast. Dry greenware fully and ramp slowly.
Q: Is homemade porcelain food-safe?
A: Only if you use lead-free glaze and fire to maturity. Test for leaching before using with food or water.
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