- Produces harder and stronger casts than HYDROCAL® Brand White Gypsum Cement.
- Basic gypsum cement with excellent plasticity development.
- Recommended for both solid and hollow casting.
- Very white in color
and can accept colorants easily.
| Technical Properties | English | Metric |
| Use Consistency (parts of water by weight per 100 parts plaster ) | 40 | 40 |
| 1 Hr. Compressive Strength | 3,000 psi | 6.9 MN/m2 |
| Dry Compressive Strength | 6,500 psi | 44.8 MN/m2 |
| Maximum Setting Expansion | 0.250% | 0.250% |
| Density | ||
| Wet | 113.0 lb/ft3 | 1.81 g/cm3 |
| Dry | 96.0 lb/ft3 | 1.54 g/cm3 |
| Set Time (Machine Mix)* | 25-35 min. | 25-35 min. |
| *Other set times may also be available. Call your sales representative for more information. | ||
General Directions and Guidelines
Mixing the Statuary HYDROCAL Brand Gypsum Cement slurry is one of the most important steps in producing Statuary HYDROCAL Brand Gyspum Cement casts with maximum strength, hardness, and other important properties.
Mechanically mixed
slurries develop uniform casts with optimal strengths. Statuary HYDROCAL
Brand Gypsum Cement can be mechanically mixed through both batch and continuous
processes. Proper blade and bucket dimensions are important for obtaining
the best batch mix. Longer mixing times result in higher cast strength
and shorter setting times. The relationship between mixing time and both compressive
strength and setting time is shown below.
To prevent air entrainment and provide a uniform, smooth surface, careful pouring of the slurry is necessary. Agitation of the filled mold is a further step used to prevent air at or near the surface of the cast piece. Whenever possible, the slurry should be poured carefully in the deepest area so the slurry flows evenly across the surface of the mold.
Pouring a large amount of slurry directly on the face of the mold may result in slight densification of the cast at the point where the slurry strikes the surface of the mold.
All casts should be dried as quickly as is safely possible after manufacture so that maximum physical properties can develop. Dry to a constant weight.
The best drying rooms or ovens provide (1) uniform and rapid circulation (minimum of 15-30 fps) of air with no dead spots having little or no air movement, (2) equal temperatures throughout the entire area, and (3) provisions for exhausting a portion of the air while replacing it with fresh air. High humidity surrounding the drying room or oven inhibits the efficiency of the drying because the air pulled into the room is incapable of picking up much moisture from the cast pieces.
The maximum temperature at which Statuary HYDROCAL Brand Gypsum Cement casts are safe from calcination is 120°F (49°C). With substantial free water in the cast piece, higher drying temperatures can be used without difficulty. As drying progresses, the temperature must be reduced to prevent calcination. The safe drying zone is in the shaded area of graph (below, right). Before removing casts from the dryer, the temperature should approach that of the area around the dryer to prevent thermal shock.
