Silicone for Plaster & Porcelain Plaster - Making Plaster Molds
Professional Silicone for Plaster and Porcelain Plaster Molds Discover our extensive range of silicones for plaster molds , specially selected for creating high-quality molds for plaster, porcelain plaster, cement, concrete, and related casting materials. Our silicones offer excellent detail reproduction, durability, and easy demoulding for perfect plaster casts. Why Silicone...
✔ Flexible, Strong, good resistance to pu and epoxy
✔ White, Good Fluid, Bleeding
✔ Shore (A) 23 ~ 26
✔ Low shrinkage (<0.3%)
✔ 120 minutes working time
✔ Mix ratio (Weight) 100: 5
✔ Very fast
✔ Low dosage
✔ Can be used neat or mixed
✔ Retain properties of other hardener at low dosage
✔ Low shrinkage (< 0.3 %)
✔ 5 minutes working time
✔ Mixing ratio (Weight) 100:2
✔ 3-4% dosage
✔ dry, stretchable result
✔ Can be used neat or mixed
✔ Low shrinkage (< 0.3%)
✔ Better resistance to PU and Epoxy
✔ Mixing ratio (Weight) 100:5
✔ Long processing time
✔ 2% dosage
✔ Medium fast
✔ Can be used pure or mixed
✔ Low shrinkage (< 0.3%)
✔ Mainly used for Elastosil M 1470
Professional Silicone for Plaster and Porcelain Plaster Molds
Discover our extensive range of silicones for plaster molds , specially selected for creating high-quality molds for plaster, porcelain plaster, cement, concrete, and related casting materials. Our silicones offer excellent detail reproduction, durability, and easy demoulding for perfect plaster casts.
Why Silicone for Plaster Molds?
Silicone is the ideal material for plaster molds because:
Water resistance - No reaction with damp plaster materials
Flexibility - Easily deformable without damaging delicate details
Non-stick coating - Plaster comes off effortlessly without release agent
Detail rendering - Reproduces finest textures and ornaments
Sustainability - Hundreds of casts possible per mold
Dimensional stability - Minimal shrinkage for accurate reproductions
Chemical resistance - Resistant to alkaline gypsum materials
Recommended Silicones for Plaster and Porcelain Plaster
RTV Silicone (Room Temperature Vulcanizing)
Platinum-catalyzed RTV silicone is the best choice for plaster molds:
Shore A 15-25 - Soft, flexible silicone for complex ornaments and undercuts
Shore A 30-35 - Versatile hardness for most plaster applications
Shore A 40-50 - Stronger molds for large plaster casts and production
Polytek Silicone for Plaster
Polytek TinSil 80 series - Economical tin-silicone for large plaster molds
Polytek PlatSil Gel series - Platinum silicone for superior detail rendering
Polytek PolyGel - Gel silicone for brush molds on large objects
Polytek Poly 74 series - Versatile polyurethane rubbers as an alternative
Wacker and CHT Silicones
Wacker Elastosil M - Professional quality for architectural reproductions
CHT Silicone - Reliable performance for plaster crafts
Zhermack Elite Double - Precision silicone for fine details
How to Make a Silicone Plaster Mold?
Method 1: Block Mold
The most commonly used method for plaster molds:
Preparation - Place your master model (original object) in a leak-proof container
Attachment - Glue the model to the base with hot glue or double-sided tape
Distance - Allow at least 10-15mm of silicone around the model
Release agent - Apply a release agent to porous models if necessary
Mixing - Mix silicone A and B components in the correct ratio (usually 1:1 or 10:1)
Bleeding - Remove air bubbles with vacuum chamber for optimal detail reproduction
Pouring - Pour slowly from the highest point, let the silicone flow naturally
Curing - Allow to cure for 16-24 hours at room temperature (20-25°C)
Demolding - Remove the mold and cut a casting opening if necessary
Method 2: Brush-On Mold
Ideal for large sculptures, reliefs and architectural elements:
Preparation - Clean and dry the master model thoroughly
Release agent - Apply release agent to porous surfaces
First layer - Brush a thin layer of silicone over the model (detail layer)
Air Bubbles - Work carefully to avoid air bubbles
Reinforce - Add fiberglass or cotton cloth between layers for strength
Build up - Apply 3-5 coats to a total thickness of 5-10mm
Mother mold - Make a support mold from plaster, plastic or wood
Registration Points - Add alignment marks to the parent shape
Method 3: Two-Part Mold
For 3D objects and sculptures:
Parting Plane - Determine where the mold will split (usually center)
First Half - Cover half of the model with clay up to the parting line
Registration Points - Make semi-circular depressions in the clay for perfect alignment
Malbox - Build a container around the model
First Pour - Pour the first half of the mold
Release - Apply release agent to cured silicone
Remove Clay - Remove all clay from the model
Second Pour - Pour the second half of the mold
Pouring Port - Add a funnel for easy pouring
Working with Different Plaster Materials
Porcelain Plaster (Casting Plaster)
Fine plaster for detailed casts:
Mixing ratio: 100 parts plaster to 35-40 parts water
Curing time: 20-30 minutes
Ideal for: Statues, ornaments, decorative elements
Silicone hardness: Shore A 25-35 recommended
Modeling Plaster
Stronger plaster for functional objects:
Mixing ratio: 100 parts plaster to 30-35 parts water
Mixing ratio: 100 parts plaster to 28-32 parts water
Curing time: 20-30 minutes
Ideal for: Slip casting molds, ceramic production
Silicone hardness: Shore A 35-45 recommended
Cement and Concrete
For architectural and garden elements:
Use firmer silicone (Shore A 40-50)
Apply release agent for easy demolding
Consider polyurethane rubbers for very large molds
Tips for Perfect Plaster Molds
Venting - Add small channels to allow air to escape during pouring
Pouring Opening - Make it large enough for easy pouring and filling
Wall thickness - Minimum 10mm silicone for stability and durability
Mother Mold - Always use a support mold for flexible molds
Release agent - Usually not needed, but can help with very porous models
Drying Time - Allow plaster to dry completely (24-48 hours) for optimum strength
Maintenance - Clean molds after use and store dry
Applications
Sculpture and sculptures
Architectural ornaments and moldings
Decorative ceiling and wall elements
Garden statues and fountains
Restoration of historical elements
Ceramic slip casting molds
Prototyping and model making
Concrete garden elements and tiles
Reliefs and wall panels
Frequently Asked Questions
Do I need a release agent? Not for most silicones, but for very porous models, it can be helpful.
How many casts can I make? A good silicone mold will last for 200-500+ casts, depending on complexity and maintenance.
What hardness is best? Shore A 30-35 is ideal for most plaster applications, softer for intricate details.
Can I pour cement into silicone molds? Yes, use a firmer silicone (Shore A 40-50) and a release agent.
Why platinum over tin-silicone? Platinum offers better detail reproduction and a longer lifespan, while tin is more economical for large molds.
Order your professional silicone plaster molds today from Siliconesandmore – your specialist in mold-making materials for plaster and porcelain plaster.
