Dow Corning Silicone Foam 3-82Dow Corning Silicone Foam 3-8259 RF  dow corning espumas foams

Dow Corning 3-8259 RF Silicone Foam for Compression Gaskets

Boosting Manufacturing Productivity and Product Performance

As global competition increases, manufacturers face greater demands for products that deliver high performance, long- lasting durability, greener solutions and lower costs.

Those challenges force manufacturers to find innovative solutions at every step — component design, material selection and manufacturing. Our family of silicones for foamed-in-place gaskets last longer and are more versatile and durable than organic polymer sealants — offering you long-lasting, flexible seals that are more efficient to produce.

Dow Corning silicone foams use a hybrid technology. While they are nominally a room-temperature vulcanization (RTV) technology, they use an addition cure mechanism which is typical for high-temperature vulcanization (HTV) products. Silicone foams are designed to be dispensed and cured directly on parts to form an integrated compression gasket.

Find the Foam that Fits Your Function

Dow Corning offers you a range of silicone foam products, helping you find one that meets your application needs and helps reduce suppliers and costs. The product line includes a variety of foam densities as well as flowable and reduced flowable foams, which gives you greater control over foaming height relative to flat or inclined surfaces.

Silicone foams from Dow Corning generally have low compression set, which means they recover their original shape after being compressed. Like other silicone- based elastomers, silicone foams maintain their resiliency over a broad temperature range and resist permanent compression set.


Applications and Benefits

Two-part RTV silicone foams from Dow Corning are suitable for use to form a compression gasket or environmental seal against ambient air, splashed water, dust or moisture. They offer a cost-effective, alternative sealing solution to preformed gaskets and foam tapes in applications that require:

Dow Corning silicone foams are suitable for use nearly anywhere foam tapes are used.

Typical applications include

Typical Properties of Dow Corning Silicone Foam


Product Property

Dow Corning 8257 Silicone FoamDow Corning 8257 Black Silicone FoamDow Corning 3-8209 Silicone FoamDow Corning 3-8219 RF Silicone FoamDow Corning 3-8259 RF Silicone FoamDow Corning 3-8259 RF Dark Grey Silicone Foam

Viscosity (mPas)

A: 21,000

B: 12,000

A: 20,000

B: 12,000

A: 14,000

B: 15,000

A: 21,000

B: 40,000

A: 68,000

B: 63,000

A: 64,000

B: 62,000

Snaptime (sec)230240220200200200
Tack free time (min)887676
Density (kg/m³)140150250300330330
Flowability (cm)FlowableFlowableFlowable171516
Cell structure (Zellen/3cm)3530FineFineFineFine
Hardness Shore 00252545455050


More Efficient Manufacturing

Our silicone foams are designed for efficiency in processing. The two-part silicone RTV foam is dispensed — typically with a robotic applicator — directly on the part surface

dow corning silicone foam dispensing

  1. Mixed & dispensed liquid components (no bubbles)
  2. Expanded & cured solid (elastomer with bubbles)

Figure 1: Mixing the components produces a reaction that releases hydrogen gas as a foaming agent. The gasket expands in its liquid stage and cures to a foamed solid elastomer within 10 minutes at room temperature. This provides a low-modulus, integrated compression seal with fine, uniform cell structure.

Dow Corning Silicone Foam gasket

The mixed components expand to create the gasket and cure rapidly. The foam is typically fully expanded and ready to handle within 10 minutes at room temperature. This cycle can be accelerated by elevating the temperature.


Robotic application of the fast-curing, two-part material not only makes manufacturing faster, the precision of application equipment contributes to a reduction of waste material. In many applications, silicone foams from Dow Corning can seal high-tolerance gaps with less material than standard sealing elastomers. Their light weight also helps reduce the total weight of the final product.

The two components of Dow Corning silicone foams can be mixed either in a static or dynamic mixer, offering you additional manufacturing flexibility. A dynamic mixer is recommended, however, because the type and degree of mixing and shear can affect the density, cure and cell structure of the finished foam.


Silicone Foams for Compression Gaskets
Silicone Foams for Compression Gaskets


2P-RTV Silicone Foam Gasket for FIPFG Applications
2P-RTV Silicone Foam Gasket for FIPFG Applications


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