Step-By-Step Instructions for Mixing Plaster
Note: Always wear a respirator when you work with dry materials!
1. First, figure out your quantities:
Pottery Plaster-to-Water Mixing Chart (100:70 ratio)
Note: Water measurements are approximate. Always mix by weight for precision in professional or mold-making applications.
2. Measure Water:
- Add the measured water into a clean mixing bucket first.
3. Sift in Plaster:
- Slowly sift plaster into the water, allowing it to absorb without clumping.
- Let it sit (soak) for 1–2 minutes — this is called “slaking.”
4. Mix Thoroughly:
- Hand mix or use a mechanical mixer until the consistency is smooth and creamy.
- Avoid whipping in excess air bubbles.
5. Pour Immediately:
- Pour into molds or forms promptly.
- Work time is typically 8–12 minutes, depending on temperature and plaster type.
6. Allow to Set:
- Do not disturb while setting. The initial set occurs in 15–30 minutes.
- Full cure may take 24–48 hours, depending on humidity and thickness.
7. Store Plaster
- Put any unused plaster in a bag in a dry place
Products we used in this guide
