FEBRUARY 6 2003
should be set in a complete enclosure, (such as a 300 mm x 300 mm (1'- 0" x 1'- 0")
five-sided box) or in plantings or foliage in order to achieve a neat daytime appearance.
18.104.22.168. Internal Illumination. Internal illumination may be used, but it can be costly and
subject to vandalism. Internally illuminated signs should have a metal housing. The graphics
should be routed or punched out of the metal sign face and white acrylic plastic should be
inset in the opening. The appearance of the sign face should duplicate the examples shown in
12.7.1. Sign Panel Material Options.
22.214.171.124. Aluminum. Aluminum sheeting is generally recommended because of its light
weight, ease of handling and corrosion resistance. Most base sign shops have extensive
experience with aluminum sheeting for traffic control signage.
126.96.36.199. Steel. Steel sheeting should be used for the Type F1b and F2b changeable letter
(magnetic) signs and may be used on the larger base identification signs should it prove cost
effective. Galvanize all steel sheeting prior to finishing.
188.8.131.52. Plastic, Cast Acrylic, Duralite or Polycarbonate Sheets. Provide ultraviolet-light-
resistant, surface treated opaque sheets in sizes and thicknesses indicated. These materials
may be appropriate where there is high incidence of pilferage of aluminum signs.
184.108.40.206. Fiberglass Backing Panels. Provide molded seamless thermosetting glass fiber
reinforced polyester panels in sizes and thicknesses indicated. If fiberglass is used, have the
material manufacturer submit a written warranty agreeing to repair or replace fiberglass
panels that fail due to coating degradation, chalking, fading, or fiberglass delamination or
220.127.116.11. Other. Materials such as exterior plywood or exterior masonite may be used on
non-permanent base morale signs in order to reduce costs.
12.7.2. Sign Post Material Options.
18.104.22.168. Aluminum. Aluminum posts are generally recommended because of their high
strength to weight ratio, ease of handling and corrosion resistance. These features justify the
additional cost for aluminum. Provide bituminous coating for post imbedded in concrete and
acidic soil. Soil embedded aluminum posts qualify as yielding sign supports under federal
regulations, eliminating the need for breakaway or yielding connectors. (See Breakaway or
Yielding Sign Supports in paragraph 12.8.)
22.214.171.124. Steel. Steel posts are specified for the Type D1 destination sign and may be used
for other signs as well, should they prove cost effective. Steel posts have high strength and
are less expensive than aluminum posts. However, steel posts are susceptible to rusting and