MIL-W-15154E

Abstract

This specification covers laminated oak members for ship and boat use. Such material is suitable for use as straight and curved structural members in small craft, patrol craft, minesweepers, other wooden vessels, and for other applications where structural oak laminates with fully waterproof durable adhesive bonds are desired. <b><u>Intended Use:</u></b> Oak laminates covered by this specification are suitable for marine use and for other severe exterior exposure, except exposure to marine organisms. The adhesive bonds have high strength, have extreme resistance to salt water and shrinkage and swelling, and have long time durability. No grade of laminate is defined in this specification. It is intended that procuring activities order laminates composed of combinations of one or more of the lamination grades, based on structural requirements involved. The lamination grades developed for this specification are such that they should be readily available. However, the lower quality material is more readily available and less costly than the higher grades. Where permissible by strength requirements, weight limitations, and other design factors, the lower grades should be used where feasible. Oak boards are generally manufactured and stocked in random widths therefore, edge gluing is usually desirable to prevent excessive waste. (a) <i>Mixed grain.</i> A general purpose, economical type for use where repeated wetting and drying will not occur. Cyclic wetting tends to cause excessive distortion due to mixed grain. (b) <i>Flat grain.</i> A general purpose, readily available type, suitable for most applications. (c) <i>Vertical grain</i>. A more expensive, special type for use where wearing surface is important or moisture movement across width (perpendicular to annual rings) should be a minimum. This type may be more efficiently produced by vertically laminating flat grain stock. (a) <i>Class 1-high decay resistance.</i> For service where high decay or wood destroying insect hazard exists, such as damp, humid, warm areas, having poor ventilation and exposure to freshwater leakage and condensation; for parts where replacement would be difficult and costly, and long time service is required. (b) <i>Class 2-good decay resistance.</i> For service where decay or insect hazard is moderately high, or may be high at times, but ventilation and drying is generally possible and long time service is required. May be used under adverse decay conditions where a shorter service life can be tolerated. (c) <i>Class 3-moderate decay resistance.</i> For service where decay or insect hazard is not high or where occasional wetting occurs but good ventilation prevails and long time service is required; may be used in higher decay hazard locations where replacement or moderate service life can be tolerated; may be used under continuously submerged, waterlogged conditions. Arrangement 1 is intended for laminates which will be loaded primarily in tension. Arrangement 2 is intended for laminates which will be loaded primarily in bending. <br>