Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds

Product form

Dow Corning

Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds

✔ Flexible, Strong, High PU and polyester resin resistance
✔ Beige, Good Fluid, Non-Bleeding
✔ Shore (A) 18 ~ 21
✔ Low shrinkage (0.2 ~ 0.4%)
✔90 ~ 120 minutes working time
✔ Mixing ratio (Weight) 100: 5 Read more

€33,50 Incl. BTW

SKU: S10436

30-day return period

More than 100,000 satisfied customers

Pay afterwards with Klarna

Lowest Price Guarantee on Silicones– We match the price +5% extra discount

This product is ordered regularly

Make a choice

1.05 kg. Set (A+B)
5.25 kg set (A + B)
26.25 kg set (A + B)
210 kg set (A + B)

1.05 kg. Set (A+B)

€33,50

€31,90/kg

5.25 kg set (A + B)

Save €6,95 by volume

€160,55

€30,58/kg

26.25 kg set (A + B)

Save €90,11 by volume

€747,39

€28,47/kg

210 kg set (A + B)

Save €942,35 by volume

€5.757,65

€27,41/kg

✅ Lowest Price Guarantee – Europe
Found this silicone product cheaper elsewhere in Europe? We match the price + 5% extra discount. Terms

Do you have a question about this product?

Contact Us

✔ Flexible, Strong, High PU and polyester resin resistance
✔ Beige, Good Fluid, Non-Bleeding
✔ Shore (A) 18 ~ 21
✔ Low shrinkage (0.2 ~ 0.4%)
✔90 ~ 120 minutes working time
✔ Mixing ratio (Weight) 100: 5

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.

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)
	📥 EN SDS SILASTIC TM RTV-3481 📥 EN SDS SILASTIC RTV-3081-R

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	Avoid breathing vapours/spray Contaminated work clothing should not be allowed out of the workplace Wear protective gloves/clothing/eye protection/face protection IF ON SKIN; wash with plenty of water and soap If skin irritation or rash occurs; get medical advice/attention Take off contaminated clothing and wash before reuse
Warning	H373	May cause damage to organs through prolonged or repeated exposure	P260 P501	Do not breathe dust/fume/gas/mist/vapours/spray Dispose of contents/container in accordance with local regulations

More information about H and P statements: UK HSE &ECHA

Our story

Our story began with our father, the founder of Nedform BV. We— Roel, Rutger, and Rob Collaris —are his sons and wanted to bring his passion and knowledge to the online world. That's how SAM (Silicones and More) was born—a creative space for everyone.

Whether you're a beginner, an expert, or an enthusiastic DIYer looking for the right tools, materials, and some guidance, you've come to the right place. We've worked with silicones, resins, and casting materials ourselves for years. That's why we not only deliver quality but also genuine support—based on experience.

Small team with a great love for creating

Honest advice and reliable materials!

We help makers bring their ideas to life.

More about us

FAQs

What is the delivery time of my order?

Orders placed and paid for on business days will be shipped on the same day in most cases. Orders received on weekends will be processed on the next business day.

We always do our best to ship orders as quickly as possible, but actual shipping times may vary due to high volume, stock availability, or carrier circumstances.

Delivery time depends on the destination country and the carrier. Below is a general indication:

Netherlands: usually within 1 business day
Belgium & Germany: typically within 1–2 business days
Other countries: depends on the destination and the local carrier

Please note: these are guidelines, not guarantees. The final delivery time may differ due to factors beyond our control, such as sorting center delays, public holidays, or exceptionally high volume.

What is the return policy?

We offer a 30-day return policy as an added service. If you'd like to return an item or if there's something wrong with your order, please email us at info@siliconesandmore.com with your name and order number within 30 days of delivery. We'll help you quickly. The full terms and conditions can be found on our returns page.

How can I track my order?

Once your order has been processed and shipped, you'll receive a track and trace code by email, allowing you to easily track your package. Please note that it can sometimes take up to 24 hours after processing for the track and trace to be active.

I have a problem with my order, how can I reach you?

If you have any questions or run into any problems, please feel free to contact us via our contact page or email us at info@siliconesandmore.com . We'll be happy to help you quickly.

If you want an immediate answer, ask our chatbot. They have extensive knowledge of all our products and can often help you right away!

Can I also order for business purposes?

Yes, business orders are possible . Customers within the EU outside the Netherlands can order VAT-free with a valid EU VAT number (0 percent intra-Community supply).

Enter your VAT number on the shopping cart page , not at checkout.

Go to the shopping cart via the link below and enter your VAT number and email address, after which the VAT will be automatically removed.

https://siliconesandmore.com/cart

Please note that if you only enter your VAT number at checkout, it will not be processed correctly and VAT may still be charged.

Huismerk - SAMSAM Bodycasting Set

Huismerk - SAMPorcelain Plaster – Premium Casting Plaster for Molds & Detailed Casts

WackerWacker Elastosil Vario 15 Normal – Translucent Platinum Silicone for Molds & Prototyping

SAM - Silicones and MoreSilicone Condensation 20 Universal Set – Molding rubber for universal molds

Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds

Dow Silastic RTV 3481 R – Condensation Silicone for Resin & Concrete Moulds

Pairs well with