ASI 306

Electronic Grade Self-Leveling Silicone

ASI 306 Electronic Grade Self-Leveling Silicone is a one-component, RTV (room temperature vulcanizing) product that uses a new cross-linking mechanism as a curing method. No acetic acid or other corrosive by-products are generated during its cure. Thus ASI 306 can be used in corrosion-sensitive electrical and/or electronic equipment with no adverse effect. Supplied ready to use, ASI 306 cures at room temperature to form a tough, high-modulus rubber. ASI 306 electronic grade self leveling silicone has excellent unprimed adhesion to a very wide range of substrates including metals (i.e. chrome), glass, most woods, ceramics and various plastics. Because ASI 306 is a 100% silicone sealant, it resists weathering, moisture vibration, ozone, ultraviolet and temperature extremes. ASI 306 remains flexible from -57°C to +204°C (-70°F to +400°F).

Typical Uses

ASI 306 is primarily used in applications where a flowable, self-leveling silicone sealant is required to fill small gaps or voids. Applications include potting electrical terminals and coating electrical devices. Since no undesirable odors are released during cure, ASI 306 is ideal where applications must be done under confined conditions. Adequate ventilation should be provided with extensive use of this product.


ASI 306 is ready to use and requires no mixing or additives. The cure mechanism begins as soon as the sealant comes in contact with the air. Uncured sealant will flow until a cured skin is formed. At conditions of 25°C (77°F) and 50% relative humidity the sealant will skin in 30 minutes and cure within 24 hours (1/8″ thickness). Higher humidity accelerates cure. In applications where partial or total confinement of sealant is prevalent, the time required for proper cure is generally lengthened by the degree of confinement.

Surface Preparation

All surfaces should be clean and dry. It is recommended that bonding surfaces be solvent wiped with a naphtha, ketone or chlorinated solvent. Suitable solvents would include xylol, toluol and mineral spirits. Do not solvent wipe with alcohols or oil-containing solvents such as Varsol. Allow surface to dry thoroughly before applying sealant.


Priming for ASI 306 Electronic Grade Self-Leveling Silicone is normally not required for applications to most substrates. Unprimed adhesion can be readily tested by applying a small trial flow and allowing 7 days for maximum adhesion to occur.


ASI 306 should not be applied to surfaces that will be painted, as painting over sealant is not recommended. The paint film does not stretch with the extension of the sealant and the adhesion of paint to ASI 306 is not adequate.

FDA Status

ASI 306 is permitted under regulations of the Food and Drug Administration where incidental food contact might be involved. FDA Regulation number is 177.2600.

Military Specifications

ASI 306 meets the requirements of MIL-46106 Type II.

Underwriters Laboratories File E209770

General Description of Material:

100% silicone sealant furnished in the form of cartridges.

Material Modifications – There shall be no changes in the formulation or composition of the material unless previously cleared through Underwriters Laboratories Inc.

Form of Shipment – The materials are produced and shipped as finished products.

About American Sealants, Inc.

Since 1987 American Sealants has become a recognized and trusted manufacturer, supplier and packager for some of the biggest brand name adhesive and industrial companies in the United States. American Sealants Inc. has grown due to its manufacturing capabilities, core values, and quality control processes. As a leader in the industry, our experienced customer service and technical team are here to ensure your satisfaction. You can be assured that you are receiving a quality product. We do not cut corners to provide cost savings – rather we offer a high performing product at a competitive price through our capabilities and processes. If you do not see something listed on our website, please do not hesitate to call and ask. With our experience we can help you get moving in the right direction.