Water Powder Ratios
Here are the basics of how to mix our alginates. For a more detailed discussion- Click HERE.
The Bucket Mold
A Hand Cast is a perfect example of a bucket mold. The alginate is mixed and placed into a container. The hand is pushed down into the alginate and removed when set. The rigid bucket keeps the alginate from distorting.
| Alginate Formula | Water/Powder Ratio (by weight) |
| 380-CC | 4:1 |
| 390-S2 | 4:1 |
| 570-PGV | 4:1 |
| 580-CC | 4:1 |
| 570-Genesis V | 4.5:1 |
| 1070-Genesis X | 4.5:1 |
| Example: | 1 pound 380-CC mixed with 4 lbs water (2 quarts) |
| Metric Example: | 500g of 380-CC mixed with 2 liters of water |
It is convenient that one pint of water (16 fl.oz.) weighs almost exactly 1 pound. This table gives more water weights.
| Water amount | Water Weight |
| 1 cup (8 fl.oz.) | 1/2 pound |
| 1 pint (16 fl.oz.) | 1 pound |
| 1 quart (32 fl.oz.) | 2 pounds |
| 1 gallon (128 fl.oz.) | 8 pounds |
The Layup Mold
A Face Cast is a perfect example of a layup mold. The alginate is mixed and placed directly onto the surface of the face. The alginate needs to be reinforced with plaster bandages so it holds its shape after it is removed.
| Alginate Formula | Water/Powder Ratio (by weight) |
| 590-IBG | 3.75:1 |
| 680-LS | 3.75:1 |
| 880 | 3.75:1 |
| 570-Genesis V | 4:1 |
| 1070-Genesis X | 4:1 |
| Example: | 1 pound 590-IBG mixed with 3 3/4 pounds water (1 quart plus 3.5 cups) |
| Metric Example: | 500g of 590-IBG mixed with 1875 ml of water |
It is also convenient that, in the metric system, water weights are easy to approximate from volume measurements.
| Water amount (metric) | Water Weight (metric) |
| 100 ml | 100g |
| 500 ml | 500g |
| 1 liter | 1 kg |
All alginates can be mixed thinner or thicker to suit your needs, but you should be aware of certain effects:
- 1. Thinner mixes will set slower- thicker mixes will set faster.
- 2. Thinner mixes will be softer, more flexible and easier to tear. The opposite is true of thicker mixes.
- 3. Thinner mixes will shrink faster than thicker ones. You'll really need to get these poured quickly.
- That having been said, we encourage you to experiment with different mixing ratios. Let us know what you come up with.
Asgard Studios.