Refsan 756 Casting Slip Powder
Refsan 756 Casting Slip Powder is a granulated ceramic casting body developed for slip casting in plaster molds and press-forming applications. Available in 5 kg, 10 kg, and 20 kg packages, it is suitable for ceramic studios, educational workshops, and production environments.
Product Specifications
- Physical FormGranulated Casting Powder
- Package Sizes5 kg, 10 kg & 20 kg
- ApplicationSlip Casting & Press Forming
- Press FormingLight Moistening Required
- Slip Density1740 g/L
- Minimum Water Addition40 L per 100 kg
Applications & Recommendations
Slip Casting
When mixed with water and the appropriate amount of electrolyte, the powder produces a casting slip suitable for plaster molds. A lump-free, homogeneous mixture is recommended to achieve uniform wall thickness and smooth surfaces.
Press Forming
The product may also be used in press-forming applications. Slight and controlled moistening of the granulated powder is recommended before pressing.
Slip Preparation
Mix the powder with water in a suitable container using a mechanical mixer until a homogeneous consistency is achieved. The prepared slip should then be passed through a sieve to remove lumps and foreign particles.
PREPARATION INSTRUCTIONS
For slip casting, add approximately 10 liters of water to every 25 kg of casting powder (approximately 40% of the powder weight).
Mix thoroughly for at least 30 minutes using a mechanical mixer, then sieve the slip. For optimum performance, allow the prepared casting slip to mature for approximately 24 hours before use.
SODIUM SILICATE ADDITION
Approximately 0.08% sodium silicate (water glass) may be added to improve slip fluidity and casting performance. Around 15 g of sodium silicate is recommended for every 25 kg of casting powder.
Accurate measurement with a precision scale is recommended. Estimating the amount using non-standard measuring methods may result in inconsistent performance.
Product Advantages
- Optimized for Slip Casting: Produces ceramic pieces with consistent wall thickness in plaster molds.
- Suitable for Press Forming: Can be used in pressing applications after controlled moistening.
- Adjustable Water Ratio: Water content can be modified according to production conditions and the desired casting consistency.
- Density Control: Slip density can be monitored using a Baumé hydrometer.
- Recommended Density: A Baumé value of approximately 58–60° is recommended for slip casting applications.
Physical Properties
- Dry Strength25 kg/cm²
- Water Absorption23.3% at 1040°C
- Firing Shrinkage4% at 1040°C
- Optimum Electrolyte Content67%
- Casting Rate0.35 mm²/min
- Thermal Expansion Coefficient70 × 10⁻⁷ 1/K
- Measurement Range20–400°C
Chemical Composition
- SiO₂50.4%
- Al₂O₃20.6%
- Fe₂O₃1.0%
- TiO₂0.7%
- CaO10.7%
- MgO0.4%
- Na₂O0.5%
- K₂O1.1%
- LOI14.4%
The required water content may vary between 40% and 60%, depending on the desired casting consistency and water absorption characteristics. Slip density should be checked with a Baumé hydrometer, and small-scale casting, drying, firing, and glazing tests are recommended before full-scale production.