Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds
Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds
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Ordered and paid on a working day: usually ships the same day
Delivery to Netherlands: usually within 1 working day
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Premium Condensation Silicone for Professional Resin and Concrete Moulds
Dow Silastic RTV 3481 R is a high-quality 2-component condensation-curing (tin-cure) casting silicone with a Shore A 19 hardness, specially developed for durable moulds with improved service life when casting polyester resin. This professional silicone combines excellent flowability (self-deairing), high mechanical strength (tensile strength 4.6 MPa) and 622% elongation with broad chemical resistance – ideal for art casting, WetCast concrete and industrial moulds. The mixing ratio is 100:5 (A:B) by weight, with a working time of 90 to 120 minutes and curing within 24 hours at room temperature.
Key Benefits
- Improved resin resistance (-R variant): Specifically tuned for longer mould life with polyester casting resin; also suitable for polyurethane, concrete, wax and soap – ideal for industrial and artistic foundries
- Excellent flowability: Viscosity 20,000 mPa·s for self-deairing casting without vacuum treatment
- High mechanical strength: 4.6 MPa tensile strength and 26 kN/m tear strength for long-lasting, durable moulds
- Extreme elongation: 622% elongation at break for easy demoulding of complex geometries and undercuts
- Long working time: 90-120 minutes pot life for mixing, deairing and filling large or highly detailed models
- Minimal shrinkage: 0.2-0.4% linear shrinkage for dimensionally accurate reproductions
Typical Applications
- Moulds for polyester and polyurethane casting resin in art casting and industrial production
- WetCast concrete moulds for precast elements, tiles and architectural ornaments
- Art casting: moulds for statues, sculptures and decorative objects
- Model making and prototyping for small series and test parts
- Honeycomb and wax casting applications
- Industrial moulds for ornaments, reliefs and architectural elements
Processing instructions:
- Stir the A component (base) thoroughly first; filler may settle during prolonged storage
- Weigh 100 parts A to 5 parts B (by weight; e.g. 50 g B per 1 kg A) and mix until the curing agent is fully dispersed
- Mix carefully by hand or mechanically; do not let the temperature exceed 35 °C
- De-air in a vacuum chamber if desired; then pour within the 90-120 minute pot life and avoid air entrapment
- Cure at room temperature (22-24 °C); demould after a maximum of 24 hours. Final properties are reached within 7 days
Spatula moulds: Add 0.6-2% Thixo C (typically 1%) to thicken the mixture for spatula applications. Combine with a support shell of plaster (bandage), epoxy putty or acrylic resin with glass fabric.
Note: Temperature and humidity affect the curing speed; higher temperature and humidity shorten the working time. Condensation-curing silicones can soften and lose elasticity under prolonged exposure above 150 °C or when fully confined at high ambient temperature. This is an industrial product and is not intended for food, dental or skin-contact applications.
Dow is a world leader in silicone technologies for professional foundries, construction applications and industrial moulds, with decades of expertise in condensation silicones.
Professional Support
Our technical specialists advise on mixing ratios, curing speeds, support-shell construction and optimal results for your specific resin or concrete mould application. Contact us for technical data sheets or advice on condensation silicones for your project.
Product Properties
- Hardness19Shore AHardness of the silicone material
- Shrinkage0.3%Linear shrinkage after curing
- ColorOff-whiteColor of the finished product
- Viscosity20000mPa·sViscosity of the uncured silicone
- Mix ratio100:5Mixing ratio A : B
- Tensile strength4.6MPaMaximum tensile force before breaking
- Tear strength26.0kN/mResistance against tearing
- Elongation at break622%Maximum stretch before breaking
- Pot life120minutesWorking time after mixing
- Cure time3600minutesTime until full cure
Component Properties
- Color ABeigeColor of component A
- Color BTransparentColor of component B
Application
- Use caseMoulds for polyester and polyurethane casting resin, concrete and the reproduction of figures and art objectsIntended use
- Silicone type["Condensation curing","RTV-2"]Type of silicone or polymer
- Cure speedSlowHow quickly the material can be demoulded
Safety Information
If you frequently work with the silicones, it is recommended to wear gloves during processing and to ventilate the area well. For safety instructions, always consult the safety data sheet.| Safety Pictograms | Safety Data Sheets (SDS) |
|---|---|
GHS hazard pictograms
 
Required protection (ISO 7010)
     |
| Signal Word | H‑code | Hazard Statement | P‑codes | P‑statements |
|---|---|---|---|---|
| Warning | H317 | May cause an allergic skin reaction | P261 P272 P280 P302+P352 P333+P313 P362+P364 |
|
| Warning | H373 | May cause damage to organs through prolonged or repeated exposure | P260 P501 |
|
Technical data sheets
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Frequently asked questions
What is the delivery time for my order?
Orders placed and paid on working days are in most cases shipped the same day. Weekend orders are processed on the next working day.
Indicative delivery times: Netherlands usually within 1 working day, Belgium and Germany typically 1–2 working days, other countries depending on destination and carrier. These are guidelines, not guarantees: peak periods, public holidays or carrier delays can have an effect.
What is the return policy?
You have 30 days to return after receipt. Email info@siliconesandmore.com within 30 days of delivery with your name and order number. The full conditions are in our return policy.
How can I track my order?
As soon as your order has shipped, you'll receive a track & trace code by email. It can take up to 24 hours before the code is active.
I have a problem with my order – how do I reach you?
Contact us via our contact page or email info@siliconesandmore.com. We're happy to help you quickly.
Can I order as a business?
Yes. Apply for a business account; we review your application within 3 working days. After that you order while logged in and pay on invoice, with payment terms of 14 days after delivery.
EU businesses outside the Netherlands with a valid VAT number order with VAT reverse-charged (0%, intra-community supply). The VAT number is stored in your business account; it cannot be added to an order after it has been placed.