Wacker Elastosil M 4511 — RTV-2 Silicone Rubber for Mold Making
ELASTOSIL M 4511 is a pourable, condensation-curing RTV-2 silicone rubber with extremely low Shore A hardness (~12), outstanding tear strength, and 600% elongation. Designed for cost-effective mold making with polyester and polyurethane resins.
- Type: RTV-2 condensation-curing silicone
- Hardness: Shore A ~12 (very soft)
- Elongation: 600% at break
- Pack size: 5.25kg kit (with catalyst)
- Brand: Wacker Chemie AG, Germany
- Shelf life: 1 year at 2–40°C
- Price last updated: July 2026
Quick Facts
How much does Wacker Elastosil M 4511 cost in India?
Wacker Elastosil M 4511 costs ₹7,375 incl GST for a 5.25kg kit, delivered PAN India from our Ghaziabad warehouse. The kit includes the silicone base and the required catalyst. As of July 2026, shipping charges apply on all orders.
What is Elastosil M 4511 used for?
Elastosil M 4511 is used for making flexible silicone molds for casting polyester resins, polyurethane resins, plaster, concrete, wax, and low-melting alloys. Its very low Shore A hardness and high tear strength make it ideal for molds with deep undercuts and intricate details.
Product Description
ELASTOSIL M 4511 is a room-temperature-vulcanising (RTV-2) silicone rubber manufactured by Wacker Chemie AG, Germany. It is a two-component, condensation-curing system that cures at room temperature when mixed with the appropriate catalyst. The base polymer is a white, pourable liquid with excellent flowability and self-deaeration properties, ensuring bubble-free molds even for complex geometries.
What sets M 4511 apart is its outstanding chemical resistance to attack by polyester and polyurethane resins, resulting in significantly extended mold life compared to standard silicone rubbers. It can produce hundreds of copies from a single mold when used with compatible casting resins. The cured rubber exhibits extremely high flexibility (600% elongation) and low Shore A hardness (~12), making demolding of parts with deep undercuts effortless.
Elastosil M 4511 is part of our epoxy resin India range and is the preferred mold-making silicone for foundries, sculpture studios, and industrial casting applications across India.
Pricing & Pack Sizes
| Pack Size | Price (incl GST) | Per-Unit Cost | Coverage |
|---|---|---|---|
| 5.25kg kit | ₹7,375 | ₹1,405/kg | ~1.4–1.7 sqm at 3mm mold thickness |
Prices updated July 2026. Shipping charges apply on all orders. PAN India delivery via Delhivery / Blue Dart. Specify catalyst preference (T21 or T51) when ordering.
Technical Specifications
| Specification | Value |
|---|---|
| Chemical type | Condensation-curing RTV-2 silicone |
| Appearance (base) | White viscous liquid |
| Mixing ratio | Base + 5 wt% catalyst (T21 or T51) |
| Dynamic viscosity at 23°C (after stirring) | 20,000 – 25,000 mPa·s |
| Density at 23°C | 1.22 g/cm³ |
| Shore A hardness | ~12 (very soft) |
| Tensile strength | 3.5 N/mm² |
| Elongation at break | 600% |
| Tear strength | ≥18 N/mm (ASTM D 624 B) |
| Linear shrinkage | Max 0.4% |
| Pot life at 23°C / 50% RH | 60–90 minutes (with 5% T21 or T51) |
| Demolding time at 23°C / 50% RH | 8–10 hours (tack-free) |
| Full cure | 4 days at 23°C / 50% RH |
| Catalyst options | T21 for epoxy/PU resins, T51 for polyester resins |
| Shelf life | 1 year at 2–40°C in sealed container |
Applications
High-copy-count molds for polyester casting — outstanding chemical resistance
Flexible molds for PU resin casting with excellent release and detail reproduction
Detail reproduction for statues, reliefs, decorative objects with deep undercuts
Low hardness and excellent ink transfer for pad printing applications
Durable molds for architectural plaster, concrete casting, and restoration work
Heat-resistant silicone for wax patterns, investment casting, and low-melt metal alloys
Why Choose Elastosil M 4511?
- Extremely low hardness — Shore A ~12 for easy demolding of complex undercuts
- Outstanding tear strength — ≥18 N/mm, molds last through hundreds of casting cycles
- Ultra-high elongation — 600% elongation at break for maximum flexibility
- Chemical resistant — exceptional resistance to polyester and PU resin attack
- Self-deaerating — excellent flow properties release air bubbles without vacuum
- Adjustable pot life — blend catalysts T21/T51 with T47 to modify cure speed
- German quality — manufactured by Wacker Chemie AG, ISO 9001 certified
- Versatile — works with polyester, PU, epoxy, plaster, concrete, wax, and alloys
How to Use Elastosil M 4511
1. Surface Preparation
Ensure the model or pattern is clean, dry, and free of dust and grease. Apply a suitable release agent for porous materials like plaster or wood. For non-porous surfaces like glass or metal, a thin layer of release agent is still recommended for easy demolding.
2. Catalyst Selection & Mixing
Use Catalyst T21 at 5 wt% for molds that will cast epoxy or polyurethane resins. Use Catalyst T51 at 5 wt% for polyester resins, plaster, concrete, wax, or low-melting alloys. Weigh the base accurately, add 5% catalyst by weight, and stir thoroughly until a uniform colour is achieved. For faster or slower cure, blend with Catalyst T47.
3. Deaeration
Allow the mixed silicone to stand for 2–3 minutes to let entrapped air rise to the surface. The material is self-deaerating — no vacuum degassing is required for most applications. For critical surface detail, a light vacuum cycle is beneficial.
4. Pouring
Pour the catalyzed silicone in a thin stream from a height of 30–50 cm to help break air bubbles. Start at the lowest point of the mold box and let the silicone flow evenly across the model surface. For vertical surfaces, pour in layers.
5. Curing & Demolding
Allow to cure at room temperature (23°C / 50% RH) for 8–10 hours until tack-free. Full mechanical properties develop after 4 days. Demold carefully — the soft rubber (Shore A ~12) is flexible enough for deep undercuts. If faster cure is needed, blend T21/T51 with T47 catalyst.
Storage & Shelf Life
Store in a cool, dry place between 2°C and 40°C. Keep containers tightly sealed when not in use. Do not expose to direct sunlight, moisture, or excessive heat. Shelf life is 1 year in original sealed containers. Once opened, use within 6 months and reseal immediately after each use. The catalyst has a separate shelf life — store in a cool, dry place away from moisture.
Frequently Asked Questions
What catalyst should I use with Elastosil M 4511?
Use Catalyst T21 at 5 wt% for molds that will process epoxy or polyurethane resins. Use Catalyst T51 at 5 wt% for polyester resins, plaster, concrete, synthetic stone, wax, or low-melting alloys. Both catalysts can be blended with T47 to adjust pot life and demolding time.
What is the Shore hardness of Elastosil M 4511?
Elastosil M 4511 has a Shore A hardness of approximately 12, classified as very soft. This low hardness provides maximum flexibility for demolding parts with deep undercuts and complex geometries.
How long does Elastosil M 4511 take to cure?
Pot life is 60–90 minutes at 23°C / 50% RH. The silicone becomes tack-free in 8–10 hours. Full mechanical properties develop after 4 days at 23°C. Cure time can be accelerated by blending catalysts with T47 or by curing at slightly elevated temperatures.
Can I use Elastosil M 4511 for epoxy resin molds?
Yes. Elastosil M 4511 is specifically designed for casting epoxy and polyurethane resins. When catalyzed with T21 at 5 wt%, it provides outstanding chemical resistance and extended mold life. This combination is ideal for epoxy casting applications.
Do you deliver Elastosil M 4511 PAN India?
Yes. We ship from our Ghaziabad warehouse via Delhivery, Blue Dart, or surface transport. Same-day delivery in Delhi NCR for orders before 11 AM. Shipping charges apply on all orders. Please specify your preferred catalyst (T21 or T51) when ordering.
What safety precautions should I take?
Wear gloves and safety glasses. Work in a ventilated area. Avoid skin contact with uncured silicone and catalyst. In case of skin contact, wash immediately with soap and warm water. See the Safety Data Sheet (SDS) for full safety instructions.
Need Elastosil M 4511?
Message us on WhatsApp — we will confirm stock, catalyst preference, and arrange dispatch from our Ghaziabad warehouse.
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