TL;DR: Make a DIY porcelain vase by casting liquid porcelain slip in a plaster mold, letting it set, then firing it in a kiln and glazing it. This tutorial walks you through mold preparation, pouring, cleanup, bisque firing, and final glazing for a durable, food-safe porcelain vase.
Step 1: Gather Materials and Prepare Your Workspace
You will need liquid porcelain slip, a two-part plaster mold for a vase shape, a bucket, a stirring stick, a sponge, a fettling knife, and a kiln. Porcelain slip has a high kaolin content, so work on a nonporous surface and wear a dust mask when handling dry materials. Ensure your plaster mold is completely dry before use; moisture causes uneven walls.
If you want to dig deeper, check out our guide on Elevate Your Home: Styling Porcelain Vases for Modern Living.
Step 2: Pour the Porcelain Slip into the Mold
Stir the slip gently to eliminate lumps, then pour it steadily into the mold until it reaches the rim. Let it sit for 10–20 minutes. The plaster absorbs water from the slip, forming a solid layer against the mold walls. For a typical vase, aim for a wall thickness of 3–5 mm. If you want a thicker base, add a second short pour after the first layer sets.
Step 3: Drain Excess Slip and Let the Cast Set
After the desired wall thickness forms, pour the remaining liquid slip back into your storage bucket. Invert the mold and let it drain for a few minutes. Then leave the mold upright to allow the cast vase to firm up. This can take 30–60 minutes, depending on humidity. The porcelain should feel leather-hard and release slightly from the mold edges.
Step 4: Remove the Vase and Clean the Seams
Gently open the mold and lift out the vase. Use a fettling knife to trim the rim and remove seam lines. Smooth rough spots with a damp sponge. Porcelain is fragile at this greenware stage, so support the vase with both hands. Let it air-dry completely for 24–48 hours until it is bone-dry.
Step 5: Bisque Fire, Glaze, and Fire Again
Place the bone-dry vase in a kiln and bisque fire to cone 04 (about 1060°C). Let it cool slowly. Next, apply a porcelain-friendly glaze by dipping or brushing. Wipe the foot ring clean to prevent sticking. Fire again to cone 6 (about 1220°C) for a vitrified, waterproof finish. Always follow your kiln and glaze manufacturer’s instructions.
Tips for Success
Keep your mold dry between pours, and never rush the drying stages. Porcelain shrinks about 12–14%, so account for that when choosing a mold size. Test your glaze on a small porcelain tile before applying it to the final vase.
FAQ
Q: Can I make a porcelain vase without a kiln?
A: No, porcelain requires high-temperature firing to vitrify. Without a kiln, the vase will remain brittle and not hold water.
Q: What is the best slip for casting a porcelain vase?
A: Use a commercial porcelain casting slip with fine particle size and low shrinkage, such as a cone 6 or cone 10 porcelain slip.
Q: How do I prevent cracks in my DIY porcelain vase?
A: Dry the greenware slowly and evenly, avoid thick-to-thin transitions, and do not open the kiln too quickly during cooling.
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