DOWSIL 739 Plastic Adhesive is a one-part, non-flowing silicone adhesive and sealant developed for dependable bonding, sealing, and gasketing across a wide range of plastic and metal assemblies. The neutral, non-corrosive moisture-cure system eliminates mixing and cures at room temperature after exposure to atmospheric humidity. Its paste consistency stays where applied, helping manufacturers create clean bond lines, vertical beads, sealed joints, and formed-in-place gaskets with controlled placement. It also supports consistent workflows across repair benches and production lines.

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DOWSIL 739 Plastic Adhesive Benefits

DOWSIL 739 Plastic Adhesive is recognized as an established industrial choice for bonding many plastics. The ready-to-use formulation supports manual cartridge application as well as controlled production dispensing, reducing preparation time and the risk of incorrect mixing ratios. Once cured, it forms a flexible silicone elastomer that can absorb movement, vibration, impact, and differences in thermal expansion between joined materials.

The non-corrosive cure chemistry makes the product suitable for assemblies where acidic cure by-products may be undesirable. Its combination of adhesion, flexibility, and electrical insulation can support reliable performance in appliance, transportation, electrical, marine, signage, and general industrial applications. Available colors may include black, white, and gray, allowing buyers to select a finish that suits the component or assembly.

Applications for DOWSIL 739 Plastic Adhesive

Typical uses include adhering automotive trim, appliance trim and components, assembling plastic toys, bonding signs and sign letters, and attaching gaskets in refrigeration equipment. DOWSIL 739 Plastic Adhesive can also be used for bonding plastic to metal, sealing flashing, vents, gutters, marine cabins, and windows, and waterproofing equipment enclosures or vehicle cabs.

For maintenance and original equipment manufacturing, the adhesive can form flexible in-place gaskets on compressors, gearboxes, pumps, housings, and covers. It may also support sealing around joints that experience vibration or moderate movement. Because plastic formulations, coatings, and surface treatments vary significantly, users should complete adhesion and compatibility testing on the actual production materials before approval.

Typical DOWSIL 739 Plastic Adhesive Performance

Dow identifies this material as a non-flowing, moisture-cure silicone with a typical tack-free time of approximately 75 minutes under specified laboratory conditions. Published guide values include a specific gravity of about 1.40, Shore A hardness near 25, tensile strength around 1.5 MPa, and elongation of approximately 500 percent. The product is also listed with a typical dielectric strength of 25 kV/mm and a UL 94 V-1 flammability classification.

These figures are typical values rather than purchase specifications. Actual curing speed and final performance depend on temperature, humidity, bead depth, substrate condition, joint geometry, and application method. Moisture-cure silicones normally cure from the exposed surface inward, so thick sections require additional time.

How to Apply DOWSIL 739 Plastic Adhesive

Clean all bonding surfaces and remove dust, oil, grease, release agents, and loose contamination. Apply a continuous bead to one prepared surface, assemble the components within the available working time, and secure them until sufficient handling strength develops. Tool exposed material before skin formation when a smooth seal is required.

For the best commercial result, evaluate bead size, bond-line thickness, fixture method, and cure time during production trials. Do not place uncured material in fully enclosed areas where atmospheric moisture cannot reach it. Review the latest technical data sheet and Safety Data Sheet before handling, storage, or large-scale use.

Why Buy DOWSIL 739 Plastic Adhesive?

DOWSIL 739 Plastic Adhesive gives manufacturers a versatile solution for plastic bonding, metal-to-plastic assembly, flexible sealing, and formed-in-place gasketing. Its one-component format, non-sag application, non-corrosive cure, high elongation, and established industrial performance can simplify purchasing and production. Choose it when your application needs a flexible silicone bond that remains durable under vibration, movement, moisture, and changing service temperatures.

industrial silicone adhesives