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) Mixed grain. 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) Flat grain. A general purpose, readily available type, suitable for
most applications.
(c) Vertical grain. 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) Class 1-high decay resistance. 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) Class 2-good decay resistance. 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) Class 3-moderate decay resistance. 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.
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