TL;DR: To make a porcelain vase, mix porcelain slip, pour it into a plaster mold, let it set, then clean, bisque-fire, glaze, and glaze-fire the piece. This guide walks you through each step safely and simply.
Step 1: Gather Materials
You need porcelain slip (pre-mixed casting clay), a two-part plaster mold, a bucket, sponge, fettling knife, kiln, and food-safe glaze. Porcelain is prized for its translucent, white body—choose a slip labeled “porcelain,” not stoneware.
If you want to dig deeper, check out our guide on Porcelain Vase Tutorial: Step-by-Step Glazing & Firing Guide.
Step 2: Pour the Mold
Stir the slip gently to remove bubbles. Pour it steadily into the plaster mold until full. Plaster absorbs water, forming a wall. Wait 10–15 minutes for a 1/4-inch wall, then pour excess slip back into the bucket. Let the mold sit 30 minutes until the vase firms up.
Step 3: Remove and Clean
Open the mold and gently lift out the greenware vase. Use a sponge to smooth seams and a fettling knife to trim the rim. Porcelain is fragile at this stage—handle with dry, clean hands.
Step 4: Bisque Fire
Let the vase air-dry for 2–3 days. Fire in a kiln to cone 04 (about 1,945°F). This hardens the porcelain without melting it. Cool slowly to prevent cracking.
Step 5: Glaze and Final Fire
Dip or brush on glaze, leaving the base unglazed. Wipe glaze off the foot to avoid sticking. Fire to cone 6 (about 2,232°F). Cool overnight. Your porcelain vase is now waterproof and ready for flowers.
Tips
Work in a dust-free area—porcelain shows every speck. Always preheat the kiln slowly. If cracks appear, mix porcelain slip with vinegar to repair greenware before firing.
FAQ
Q: Can I use earthenware slip instead of porcelain?
A: No—earthenware matures at lower temperatures and won’t give the same translucency or strength. Use true porcelain slip for best results.
Q: Why did my porcelain vase crack during firing?
A: Likely too-fast heating or uneven wall thickness. Fire slowly and ensure the vase is bone-dry before bisque firing.
Q: Is glazed porcelain food-safe for holding water?
A: Yes, if the glaze is lead-free and fired to maturity. Unglazed porcelain will seep water, so always glaze the interior.
Leave a Reply