3.6.6
Pre-Application Testing For Surface Contamination
3.6.6.1
Pre-Application Testing for Oil and Grease Contamination
Ensure tank surfaces are free of contamination as described in Article
entitled "Pre-Preparation Testing for Oil and Grease Contamination," except
that only questionable areas need be checked for beading of water misted
onto surface.
3.6.6.2
Pre-Application Testing for Soluble Salts Contamination
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NOTE: On new structures, require 30% of tests to be
accomplished at welds. On structures that have been
in service, corroded areas should also be tested for
high chlorides.
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Test surfaces for chloride contamination using the Test Kit described in
article entitled "Test Kit for Measuring Chlorides on Steel Surfaces." Test
all surfaces at rate of three tests for the first 100 square meters 1000
square feet plus one test for each additional 200 square meters 2000 square
feet or part thereof. [Concentrate testing of bare steel at areas of
coating failure to bare steel and areas of corrosion pitting. ][Perform
30% of tests on bare steel at welds, divided equally between horizontal and
vertical welds. ]One or more readings greater than 5 micrograms per square
centimeter of chlorides is evidence of chloride contamination. Reject
contaminated surfaces, wash as discussed in article entitled
"Pre-Preparation Testing for Soluble Salts Contamination," allow to dry,
and re-test until all required tests show allowable results. Reblast
tested and cleaned areas as required. Label all test tubes and retain for
test verification.
3.6.6.3
Pre-Application Testing for Surface Cleanliness
Apply coatings to dust free surfaces. To test surfaces, apply strip of
clear adhesive tape to surface and rub onto surface with finger. When
removed, the tape should show little or no dust, blast abrasive, or other
contaminant. Reject contaminated surfaces and retest. Test surfaces at
rate of three tests for the first 100 square meters 1000 square feet plus
one test for each additional 100 square meters 1000 square feet or part
thereof. Provide two additional tests for each failed test or questionable
test. Attach test tapes to Daily Inspection Reports.
3.7
MIXING AND APPLICATION OF SEALANT AND COATING SYSTEM
3.7.1
Preparation of Sealant and Coating Materials for Application
Each of the sealant, primer, intermediate, and topcoat materials is a
two-component material supplied in separate containers.
3.7.1.1
Mixing Sealant, Primer and Intermediate Coat Materials
Mix in accordance with manufacturer's instructions, which may differ for
each product. Do not mix partial kits, or alter mix ratios. Mix materials
in same temperature and humidity conditions specified in article entitled
"Delivery and Storage." Allow mixed material to stand for the required
induction time based on its temperature.
SECTION 09971
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