and re-test until all required tests show allowable results. Reblast
tested areas using vacuum equipped blast equipment. Label all test tubes
and retain for test verification.
3.9.6.3
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, clean by vacuum cleaning, 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.
3.10
MIXING AND APPLICATION OF SEALANT AND COATING SYSTEM
3.10.1
Preparation of Sealant and Coating Materials for Application
Each of the different products, sealant, primer, intermediate, and topcoat,
is a two-component material supplied in separate containers.
3.10.1.1
Mixing
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.
3.10.1.2
Pot Life
Apply mixed products within stated pot life for each product. Stop
applying when material becomes difficult to apply in a smooth, uniform wet
film. Do not add solvent to extend pot life. Add all required solvent at
time of mixing. Pot life is based on standard conditions at 21 degrees C
70 degrees F and 50 percent relative humidity. For every 10 degrees C 18
degrees F rise in temperature, pot life is reduced by approximately half,
and for every 10 degrees C 18 degrees F drop, it is approximately doubled.
Usable pot life depends on the temperature of the material at the time of
mixing and the sustained temperature at the time of application. Other
factors such as the shape of the container and volume of mixed material may
also affect pot life. In hot climates, precooling or exterior icing of
components for at least 24 hours to a minimum of 10 degrees C 50 degrees F
will extend pot life. Following are approximate pot life times:
Sealant
As specified by manufacturer
Epoxy Primer and Intermediate Coat Materials
4 hours
3.10.1.3
Application Conditions and Recoat Windows
**************************************************************************
NOTE: These requirements are provided in an attempt
to prevent the significant number of intercoat
delamination failures that are frequently found on
industrial structures. The very strict requirements
on application conditions and recoat windows may
require work during abnormal hours, including
SECTION 09973
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