Exact Mix Ratios & Working Times for FiberGel™ Alginate
Quick answer (TL;DR): For one adult hand use 300 g FiberGel + 900 ml water. Temperature matters: every 10 °F rise halves working time—see table below.
Standard Mix Ratio
All FiberGel grades use 2.5 parts water : 1 part powder by weight (e.g., 1 kg alginate → 2.5 kg water = 3.0 L at 20 °C).
| Powder (kg) | Water (kg) | Total mix (kg) |
|---|---|---|
| 0.10 | 0.25 | 0.35 |
| 0.25 | 0.63 | 0.88 |
| 0.50 | 1.25 | 1.75 |
| 1.00 | 2.50 | 3.50 |
| 1.50 | 3.75 | 5.25 |
| 2.00 | 5.00 | 7.00 |
Working & Demold Times vs Water Temperature
| Water temp | Slow-Set FiberGel | Medium | Fast |
|---|---|---|---|
| 60 °F (16 °C) | Working 4.5 min / Demold 10 min | 3 min / 8 min | 1.5 min / 5 min |
| 75 °F (24 °C) | 3 min / 8 min | 2 min / 6 min | 1 min / 4 min |
| 85 °F (29 °C) | 2 min / 6 min | 1.2 min / 5 min | 0.6 min / 3 min |
Tips for Consistent Results
- Chill water to extend time; never add extra powder.
- Drill-mix 10 sec; scrape sides; mix 5 sec more.
- Apply alginate upward so air escapes grooves.
Batch Calculator
- Half torso (220 × 300 mm) ≈ 1.2 kg powder + 3.6 L water.
- Infant hand (cup cast) ≈ 60 g powder + 180 ml water.
Written by Edmund McCormick. • Last reviewed 19 June 2025