contaminants shall be cleaned by brush with solutions of water and
detergent or trisodium phosphate, then rinsed clean with water and let dry.
Surfaces on which mildew or other microbiological growth is present shall
be cleaned with a detergent solution containing household bleach. Oil and
grease shall be removed with clean cloths and cleaning solvents prior to
mechanical cleaning. Cleaning solvents shall be of low toxicity with a
flashpoint in excess of 38 degrees C 100 degrees F. Cleaning shall be
programmed so that dust and other contaminants will not fall on newly
prepared or newly painted surfaces.
3.5
EXISTING PAINT
Existing paint shall be tested for adhesion to substrate per ASTM D 3359,
Test Method A and shall obtain a rating of 4 or better in order to be
considered sound. Existing paint meeting this requirement may be
considered a satisfactory base for repainting.
3.6
PAINT REMOVAL
Flaking, cracking, blistering, peeling or otherwise deteriorated paint
shall be removed by scraping with hand scrapers. After scraping, removal
of large areas of paint or paint on architectural details shall be
accomplished using sanders, heat guns or heat plates, or chemical paint
removers. Paint shall be removed to bare substrate or first sound paint
layer. Open flame heat devices shall not be used. Mechanical paint
removal shall not damage or mar the substrate material.
3.6.1
Chemical Paint Removers
Chemical paint removers shall be used in accordance with manufacturer's
recommendations. If chemical strippers are used, substrate shall be
neutralized after stripping to a pH of 5 to 8.5.
3.6.2
Lead Paint
In preparation of lead-based painted surfaces for repainting, procedures
described in Section 13281A LEAD BASED PAINT HAZARD ABATEMENT, TARGET
HOUSING & CHILD OCCUPIED FACILITIES shall be followed.
3.7
SURFACE PREPARATION
After cleaning and removal of deteriorated paint, edges of remaining
chipped paint shall be feather-edged and sanded smooth. Damaged areas such
as, but not limited to, nail holes, cracks, chips, and spalls shall be
repaired with suitable material to match adjacent undamaged areas. Slick
surfaces shall be roughened. Rusty metal surfaces shall be cleaned per [
SSPC SP 1] [SSPC SP 2] [SSPC SP 3] [SSPC SP 5] [SSPC SP 6] [SSPC SP 7] [
SSPC SP 10]. Chalk shall be removed so that when tested in accordance with
ASTM D 4214, the chalk resistance rating is no less than 8. New, proposed
coatings shall be compatible with existing coatings. If existing surfaces
are glossy, the gloss shall be reduced.
3.8
WOOD SURFACES
Wood surfaces shall be cleaned of foreign matter. Wood surfaces adjacent
to surfaces to receive water-thinned paints shall be primed and/or touched
up before applying water-thinned paints. Small, dry seasoned knots shall
be scraped, cleaned, and given a thin coat of commercial knot sealer before
application of the priming coat. Pitch on large, open, unseasoned knots
SECTION 09995
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