OB-OMEGABOND-AIR-SET

Supported Applications

The OMEGABOND® Air Set High Temperature Cements series comprises heat conductive, thermal shock resistant, and electrically insulating cements designed for potting, sealing, encapsulating, assembling, bonding, coating, embedding, dipping, and casting. These sodium silicate-based materials adhere to practically all clean surfaces including metals, ceramics, glass, porcelain, and most other substrates.

Documented applications include:

• OMEGABOND® 300: Assembling, sealing, insulating.
• OMEGABOND® 400: Coating, embedding, insulating.
• OMEGABOND® 500: Coating, dipping, casting; specifically used as a coating on expendable thermocouple tubes and lining for induction furnaces. It withstands short-term immersion in molten metal.

Operating Conditions & Performance

The series cures through loss of moisture by evaporation (air set) or chemical action depending on the specific model configuration, with performance characteristics varying across the three primary formulations. Maximum service temperatures range from 980°C (1800°F) for OMEGABOND® 300 to 1425°C (2600°F) for OMEGABOND® 400 and 1205°C (2200°F) for OMEGABOND® 500.

Key physical properties include:

• Thermal Conductivity: Ranges from 4-6 btu-in/ft-hr-°F (OMEGABOND® 300) to 11 btu-in/ft-hr-°F (OMEGABOND® 400).
• Coefficient of Thermal Expansion: Varies from 6.2 x 10⁻⁶ in/in°F (OMEGABOND® 300) to 13.0 x 10⁻⁶ in/in°F (OMEGABOND® 400), with OMEGABOND® 500 at 10.93 x 10⁻⁶ in/in°F.
• Electrical Insulation: Dielectric strength and volume resistivity are documented for temperatures up to 795°C (1475°F) for OMEGABOND® 300 and 400. Volume resistivity at 20°C (70°F) is listed as 10⁸-10⁹ Ω-cm.
• Media Compatibility: Resists oils, solvents, and most acids (except hydrofluoric).

Note: Physical properties were determined under laboratory conditions using applicable ASTM procedures; actual field data may vary. Strength values for OMEGABOND® 500 are specified at 1 day after curing at 220°F.

Configuration Options

The series is available in powder and liquid forms, configured as either one-part or two-part systems depending on the model:

• Mixing Configuration:
• OMEGABOND® 300 & 400 (1-Part): Powder mixed with water to a smooth, uniform consistency.
• OMEGABOND® 500 (2-Part): Mix powder and binder. The mix ratio for cast applications ranges from 1.87 to 2.0 parts powder to 1-part liquid binder by weight; a specific instruction notes a range of 1.86 parts powder to 1 part Liquid.
• Application Methods: Rolling, dipping, casting, or coating. Do not apply OMEGABOND® 500 in thickness greater than ¼" without considering chemical set alternatives for thicker applications.
• Curing Schedules:
• OMEGABOND® 300 & 400: Air dry at room temperature in 18 to 24 hours. Accelerated cure available via oven drying at 82°C (180°F). For elevated temperatures, an additional cure of 4 hours at 105°C (220°F) is recommended.
• OMEGABOND® 500: Pot life is one hour. Initial set by air drying for four hours; final set requires oven baking at 130°F for four hours. For service above 212°F, an extended cure at 220°F for 12 hours is required.
• Substrate Preparation: Porous substrates should be dampened with OMEGABOND® thinning liquid (OB-TL) before applying mixed OB-300 or OB-400. For OB-500, use the OB-500 Liquid to dampen porous substrates.

Key Product Differences

The series includes distinct models differentiated by thermal conductivity, maximum temperature rating, and chemical composition:

• OMEGABOND® 300 (OB-300): Characterized by lower thermal conductivity and coefficient of thermal expansion. Maximum service temperature is 980°C (1800°F). Compressive strength is 3900 psi; tensile strength is 410 psi.
• OMEGABOND® 400 (OB-400): Features higher thermal conductivity and coefficient of thermal expansion with a high maximum temperature rating. Maximum service temperature is 1425°C (2600°F). Compressive strength is 3300 psi; tensile strength is 325 psi.
• OMEGABOND® 500 (OB-500 POWDER / OB-500 LIQUID): A two-part sodium silicate base cement. Maximum service temperature is 1204°C (2200°F) per the manual or 1205°C (2200°F) per the data sheet table. Compressive strength is 1500 psi; tensile strength is 150 psi.
• Accessories:
• OB-KIT-1: Air set cement kit for research purposes, including 2 fluid oz each of OB-300, OB-400, OB-500 powder, and OB-500 liquid.
• OB-TL: Thinning liquid (8 fluid oz) used to dampen porous substrates before application of mixed OB-300 or OB-400 cements.