MIL-HDBK-1110
stable and have longer service lives. Applications are usually
made with a caulking gun. However, some of these materials may
also be available as putties or in preformed extruded beads that
can be pressed in place.
Putty and glazing compounds are supplied in bulk and
applied with a putty knife. Putties are not flexible and thus
should not be used for joints and crevices. They dry to form a
harder surface than caulking compounds. Glazing compounds set
firmly, but not hard, and thus retain some flexibility. Rigid
paints, such as oil/alkyds, will crack when used over flexible
caulking, sealing, and glazing compounds and should not be used.
Acrylic-latex paints, such as TT-P-19, Paint, Latex (Acrylic
Emulsion, Exterior Wood and Masonry) are a better choice.
6.2.2
Cementitious Surfaces. Epoxy resin systems for
concrete repair are described in MIL-E-29245, Epoxy Resin Systems
for Concrete Repair. This document describes epoxy repair
materials for two types of application. They are: bonding
hardened concrete to hardened concrete, and using as a binder in
mortars and concrete. These types are further divided into
classes based on working temperature. Thus, an appropriate
material can be specified.
6.3
Recommendations by Substrate. Each different type of
construction material may have a preferred surface preparation
method. For substrates, grease and oil are usually removed by
solvent or steam cleaning and mildew is killed and removed with a
hypochlorite (bleach) solution, as described in par. 5.17.4.
6.3.1
Wood. Bare wood should not be exposed to direct
sunlight for more than 2 weeks before priming. Sunlight causes
photodegradation of surface wood-cell walls. This results in a
cohesively weak layer on the wood surface which, when painted,
may fail. If exposed, this layer should be removed prior to
painting by sanding. Failure of paint caused by a degraded-wood
surface is suspected when wood fibers are detected on the
backside of peeling paint chips.
When the existing paint is intact, the surface should
be cleaned with water, detergent, and bleach as needed to remove
surface contaminants, such as soil, chalk, and mildew. When the
existing paint is peeling and when leaded paint is not present,
loose paint can be removed by hand scraping. Paint edges should
be feathered by sanding. Power sanding may damage the wood if
improperly done. Water and abrasive blasting are not recommended
for wood, because these techniques can damage the wood. When
leaded paint is present, special precautions, such as wet
scraping, should be taken. Refer to Section 3.
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