MIL-A-46146B

Abstract

This specification covers three groups of one-part, room temperature-vulcanizing, non-fuel resistant, silicone compounds which cure to durable, rubber sealants and adhesives upon contact with moisture in the air. This specification also covers primers (see <a>6.1.3</a>) for use with the silicone compounds. <br>a. Silicone adhesive-sealants covered by this specification are not fuel resistant. <br>b. Silicone adhesive sealants in each group liberate alcohol during cure. <br>The silicone adhesive-sealants shall be classified into groups according to their intended use and outstanding property (see <a>6.1</a> and <a>6.2</a>). </span><pre> Group I - General purpose Group II - High strength Group III - High temperature</pre> <br> <br>Each group of silicone adhesive-sealants shall be subdivided into types as follows (see <a>6.1</a> and <a>6.2</a>). <pre> Type I Thixotropic paste Type II - Self-leveling liquid</pre> <br> <br>The primer (if required) shall be as recommended by the manufacturer of the silicone-adhesive (see <a>6.1.3</a>). <strong>Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Director, U.S. Army Laboratory Command, Materials Technology Laboratory, ATTN: SLCMT-MEE, Watertown, MA 02172-0001 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.</strong> <br>The silicone adhesive-sealants shall be designated as follows (see <a>6.4</a>): <a><img alt="ILLUSTRATION" /></a> <br><b><u>Intended Use:</u></b> Since the silicone adhesive-sealants are available as thixotropic pastes, or as self-leveling liquids, they lend themselves to a variety of application techniques which are easily adapted to speciality uses as well as to production line methods. As these materials are non-corrosive to copper and other sensitive metals they are gaining wide acceptance as preferred adhesives and sealants where delicate electronic devices are involved. They are used in sealing instrument cases, as environmental seals for sealing electronic devices, as terminal sealants, for potting electronic components and as high temperature sealants. These silicone adhesive-sealants are not resistant to many types of fluids such as fuel and hydraulic fluids. With these one-component adhesive sealants which require moisture from the air to cure, the thicknesses should be limited to &#189; inch (13 mm), and the glue lines limited to 1 inch (25 mm) between nonporous substrates. The use of a primer is recommended for various substrates to achieve consistent results and obtain optimum adhesion when the silicone adhesive-sealant is exposed to water, high humidity and elevated temperature conditions. A primer should be used only as directed by the manufacturer and should be used only with the adhesive-sealant for which the primer was supplied. The use of silicone adhesive-sealant and primer combinations other than those recommended by the manufacturer may lead to loss of adhesion or bond failure. <br>