Brand Dowsil Application Type Bond, Sealant 1 Part or 2 Part 1 Part Material Form Nonslumping paste Substrate Glass, Many reactive metals, Plastics, Ceramics, Silicone or organic resins Industry E-Mobility Solutions, Smart Meters, Power Tools, Smart Home Devices Manufacturer Dow Chemistry Silicone, Vulcanized silicone rubber, Polydimethylsiloxane Application Method Spatula Cure Method Moisture Cure Temperature (°C) Room temp cure Viscosity (cPs) Non-flowing Color White High Temperature Resistance (°C) 200 Low Temperature Resistance (°C) -45, -55 Durability Tough Key Specifications UL, Mil-Spec (United States Military Standard): MIL-A-46146
Technical Data for Dow Dowsil 738 Electrical Sealant
1 Part or 2 Part
- 1 Part or 2 Part - 1 Part
- Paste - Nonslumping paste
- E-Mobility Solutions
- Smart Meters
- Smart Home Devices
- Power Tools
- Other - Polydimethylsiloxane
- Silicone - Vulcanized silicone rubber
- Dispenser - Automated or manual needle dispense
- Spatula/Trowel - Spatula
- Moisture / Condensation Cure - Moisture
- UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association) - UL
- Mil-Spec (United States Military Standard): A-46146 - MIL-A-46146
Cure Temperature (°C) Room temp cure Viscosity (cPs) Non-flowing Tack Free Time (min) 89 Test Method Work / Pot Time (min) 20 Test Method
Peel Strength (piw) 24 (ppi) Test Method Tensile Strength (psi) 360
High Temperature Resistance (°C) 200 Low Temperature Resistance (°C) -45, -55
Dielectric Strength (V/mil) 475
Durability Tough Shore A Hardness 35 Elongation (%) 500, High Modulus (psi) 70 Test Method
Specific Gravity 1.040 Test Method
Shelf Life Details When stored at or below 90°F (32°C), Dow Corning 738 Electrical Sealant has a shelf life of 7 months from date of manufacture.;Since this material cures by reaction with moisture in the air, keep the container tightly sealed when not in use. A plug of cured material may form in the tip of the tube during storage, but is easily removed and does not affect the remaining contents. Shelf Life Temperature (°F) <90 Shelf Life Type from the date of manufacture Shelf Life (mon) 7
Not Good For
Don't Use With surfaces to be painted
Best Practices for Dow Dowsil 738 Electrical Sealant
All surfaces should be thoroughly cleaned and/or degreased with Dow Corning® brand OS Fluids, naphtha, mineral spirits, methyl ethyl ketone (MEK) or other suitable solvent. Solvents such as acetone or isopropyl alcohol (IPA) do not tend to remove oils well, and any oils remaining on the surface may interfere with adhesion. Light surface abrasion is recommended whenever possible, because it promotes good cleaning and increases the surface area for bonding. A final surface wipe with acetone or IPA is also useful. Some cleaning techniques may provide better results than others
users should determine the best techniques for their particular applications.
Apply Dow Corning 738 Electrical Sealant to the prepared surface in a uniform thickness of 10 to 30 mils. If this adhesive/sealant is to be used between two surfaces, apply to one surface and allow it to establish uniform contact before putting the other surface in place. When placing the second surface, use enough pressure to displace the adhesive/sealant.
Let the unit stand undisturbed at room temperature until it cures sufficiently. The odor given off during cure is due to the liberation of an alcohol. The odor will disappear when the cure is complete.
Curing continues inward from the surface. In 24 hours (at room temperature and about 50 percent relative humidity), Dow Corning 738 Electrical Sealant will cure to a depth of 70 mils. If both bonded members are impermeable to moisture, as in the case of two metal plates, cure time will depend on the thickness of Dow Corning 738 Electrical Sealant and the area under the joint. The larger the unexposed bond area, the longer the cure time required. For shorter cure time and maximum bond strength, keep the area enclosed by a joint to a minimum. For best results, a metal-to-metal bond should not overlap more than one inch.
Due to the wide variety of substrate types and differences in substrate surface conditions, general statements on adhesion and bond strength are impossible. To ensure maximum bond strength on a particular substrate, 100 percent cohesive failure of the adhesive in a lap shear or similar adhesive strength test is desired. This ensures compatibility of the adhesive with the substrate being considered. Also, this test can be used to determine minimum cure time or can detect the presence of surface contaminants such as mold release agents, oils, greases and oxide films.
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Tack Free Time Test Methods
|Tack Free Time||Tack Free Temperature|
Work / Pot Time Test Methods
|Work / Pot Time||Test Method||Temperature|
|20 min||CTM 0098, At 77°F 25°C and 50% RH.||25°C|
Peel Strength Test Methods
|Peel Strength||Test Method|
|24 (ppi)||Unprimed Adhesion - 180 Degree Peel Strength|
Modulus Test Methods
|70 psi||Tensile Modulus|
Specific Gravity Test Methods
|Specific Gravity||Test Method|