Silicone – Professional Mouldmaking Materials for High-Precision Replication

TIN-CURE SILICONE (CONDENSATION-CURE)

Reliable, budget-friendly, and highly versatile

Tin-cure silicone (RTV) is widely used for general mouldmaking. It cures by condensation and provides an excellent balance between price, ease of use, and performance — making it ideal for artists, hobbyists, educators, and professionals who need dependable moulds with strong detail reproduction.

Key Advantages

• Highly versatile: Suitable for plaster, concrete, wax, soap, low-temperature resin systems, polyurethane foam, gypsum, and more.

• Excellent detail capture: Reproduces fine textures and surface patterns with high accuracy.

• Cost-effective: Often the preferred choice for medium- to large-scale moulds.

• Forgiving mixing and working properties: Ideal for beginners and advanced users.

• Good tear strength: Handles complex shapes and moderate undercuts reliably.

• Works with most model materials: Minimal risk of cure inhibition.

Considerations

• Limited lifespan: Tin-cure silicone degrades more quickly over time than platinum-cure equivalents, especially when exposed to harsh cast materials.

• Slight shrinkage during curing: Typically 0.2–0.6% — acceptable for most artistic and hobby applications but relevant for precision-critical moulds.

• Not food-safe: Should not be used for culinary moulds.

Best Uses

• Concrete and plaster moulds

• MakeMake ConcreteClay texture stamps

• Decorative objects and architectural details

• Soap and candle moulds

• Wax and low-temperature cast materials

• One-off or short-run casting projects

• Larger moulds where flexibility and affordability matter

PLATINUM-CURE SILICONE (ADDITION-CURE)

High-performance, long-life silicone for demanding and professional applications

Platinum-cure silicone is the industry standard for premium mouldmaking. It cures by addition (no by-product release), offering exceptional stability, long mould life, and near-zero shrinkage.

Key Advantages

• Extremely long mould life: Ideal for repeated casting, commercial production, and industrial use.

• Zero shrinkage: Maintains precise dimensions, making it suitable for engineering parts and precision modelling.

• Superior tear strength and elasticity: Handles deep undercuts and complex shapes with reduced risk of tearing.

• High chemical resistance: Withstands aggressive resins, PU materials, epoxies, and high-heat casting systems.

• Food-safe options available: Suitable for chocolate, fondant, and culinary moulding (when rated for food contact) - The silicone material is FDA compliant for food contact according to 21 CFR §177.2600.

• Exceptional surface reproduction: Captures micro-textures, pores, and fine lines with extraordinary accuracy.

Considerations

• Risk of cure inhibition: Can be inhibited by sulfur, tin residues, latex, certain clays, adhesives, and some 3D-printed materials. Proper testing and sealing are required.

• Higher cost: Reflects the superior performance and longevity.

• More sensitive to environment: Humidity, temperature, and surface contaminants may influence cure performance.

Best Uses

• High-detail, precision moulds

• SFX lifecasting (faces, hands, body forms)

• Prosthetic making and prop creation

• Architectural prototypes and museum-quality replicas

• Industrial components and engineering moulds

• Long-run casting production

• Highly detailed figurines, miniatures, and art pieces

CHOOSING THE RIGHT SILICONE

Both silicone types are excellent — the right choice depends on your priorities:

SILICONE IN CREATIVE AND INDUSTRIAL WORKFLOWS

Whether you are creating a small hobby mould or a large architectural reproduction, silicone provides essential benefits:

Exceptional Flexibility

Silicone stretches and bends without deformation, making demoulding easy — even with deep undercuts.

High Temperature Resistance

Safe for casting materials like wax and low-melt metals (depending on formulation).

Chemical Stability

Resists moisture, UV light, and most chemicals.

Consistent Performance

Silicone does not shrink or expand after cure, ensuring identical results across casting cycles.

USING SILICONE WITH MAKEMAKE MATERIALS

Silicone moulds are ideal for casting:

• MakeMake ConcreteClay

• Epoxy and polyurethane resins

• Plaster and gypsum

• Wax and soap

• Jesmonite-type materials

Because silicone is flexible and non-stick, it reliably releases even highly detailed concrete textures, making it perfect for creating:

• Rock structures

• Texture stamps

• Decorative surfaces

• Props and artistic reproductions

• Garden ornaments

• Concrete tiles and panels

SILICONE COMPATIBILITY & CURE INHIBITION

RTV silicone (Room Temperature Vulcanizing silicone) is a general term for silicone rubbers that cure at room temperature. MakeMake offers both tin-cure (condensation cure) and platinum-cure (addition cure) RTV silicones for mould making, casting and technical applications.

Most materials are fully compatible with RTV silicone. However, certain chemicals may interfere with the curing process, causing the silicone to remain soft, tacky or uncured. This phenomenon is commonly known as cure inhibition.

Platinum-Cure Silicone

Platinum-cure silicone offers excellent dimensional stability, very low shrinkage and long service life. However, it is also the silicone system most susceptible to cure inhibition.

Materials that may inhibit platinum-cure silicone include:

• Sulphur-containing materials, including sulphur-based plastiline clays, natural rubber, latex and certain modelling clays.
• Amines, commonly found in epoxy curing agents and some polyurethane systems.
• Tin compounds and certain catalyst residues, including residues from some construction silicones, sealants, coatings, fillers and caulks.
• Fresh polyester resins containing residual styrene or organic peroxides.
• Cyanoacrylate adhesives (super glue).
• UV resins and certain 3D printing materials that have not been fully post-cured.

Even small amounts of these contaminants can locally inhibit curing.

Tin-Cure Silicone

Tin-cure silicone is considerably more tolerant towards most substrates and is generally unaffected by materials that commonly inhibit platinum systems.

Although cure inhibition is much less common, highly reactive chemicals or incompletely cured materials may still affect the curing process. Whenever compatibility is uncertain, a small-scale test is recommended.

Materials Normally Compatible with RTV Silicone

Both platinum-cure and tin-cure RTV silicones are generally compatible with:

• Glass
• Aluminium
• Stainless steel
• Acrylic
• Concrete
• Plaster and gypsum
• Dry timber
• Polyethylene (PE)
• Polypropylene (PP)
• Fully cured epoxy
• Fully cured polyurethane
• Silicone pigments specifically formulated for RTV silicone

Silicone-to-Silicone Moulding

Fresh silicone bonds extremely well to cured silicone.

When producing two-part moulds or casting fresh silicone against an existing silicone mould, always apply a suitable release agent. Without an effective barrier, the two silicone surfaces may chemically bond together, making separation impossible without damaging the mould.

Best Practice

Whenever working with unfamiliar materials, always perform a small compatibility test before producing a full mould.

A simple 10–20 g test casting is usually sufficient to verify substrate compatibility and identify potential cure inhibition before committing to a larger project.