Dow silicones: Silastic mould making rubbers Dow is one of the largest silicone manufacturers in the world. Its silicone business was known for years as Dow Corning, originally a joint venture of The Dow Chemical Company and Corning. Since 2016 Dow Corning has been fully part of Dow, and products...
Dow (Dow Corning) Silastic silicones (2)
Dow silicones: Silastic mould making rubbers
Dow is one of the largest silicone manufacturers in the world. Its silicone business was known for years as Dow Corning, originally a joint venture of The Dow Chemical Company and Corning. Since 2016 Dow Corning has been fully part of Dow, and products are sold under the Dow name with brands such as SILASTIC and DOWSIL. If you still hear “DC 3481” in mould making, it refers to the same Silastic RTV 3481.
Dow silicones in our range
Silastic RTV 3481 R
Dow Silastic RTV 3481 R is a two component condensation cure silicone for strong, durable moulds. The rubber resists aggressive casting materials such as polyester, polyurethane and epoxy, and is widely used for moulds for concrete, plaster and casting resin.
Silastic RTV 3481 Fast
Dow Silastic RTV 3481 Fast uses the same base with a faster cure. Useful when you want to make more moulds per day or demould sooner.
Why choose Dow Silastic RTV 3481?
- A proven material used in mould making for decades
- Good resistance to casting resin and concrete, so a long mould life
- Condensation cure silicones are insensitive to most forms of cure inhibition, helpful with difficult masters
- Consistent quality from batch to batch
Condensation or addition cure?
Silastic RTV 3481 is a condensation cure silicone. These are more economical per kilo and tolerate contact with many model materials, but shrink slightly more than addition cure silicones and are not suitable for food contact. If you need dimensional accuracy or food safety, look at the addition cure silicones. All condensation systems are under condensation cure silicones, and for concrete work there is a dedicated selection of silicones for concrete moulds.
Processing tips
- Work at room temperature, around 23 °C; cold slows the cure, heat speeds it up
- Weigh component A and the catalyst accurately and mix thoroughly, including sides and bottom
- Preferably degas the mix under vacuum for a bubble free mould
- Let a new mould post cure for a few days before casting aggressive resins
Frequently asked questions
Is Dow Corning the same as Dow?
Yes. Dow Corning has been merged into Dow. The products are unchanged; only the company name on packaging and documentation has changed.
Are Dow silicones food safe?
The Silastic RTV 3481 series is a condensation cure silicone and not intended for food contact. For food moulds, choose from our food safe silicones.
Can I order other Dow products?
Looking for a Dow or DOWSIL product that is not in the web shop? Request it via contact and we will see what we can supply.
Need help choosing the right mould rubber? Our material specialists will advise you based on your master, casting material and run size.