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Characteristic
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Requirement
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1
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Design of coating system
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| .1
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Selection of the coating
system
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The
selection of the coating system shall be considered by the parties involved
with respect to the service conditions and planned maintenance. The
following aspects, among other things shall be considered:
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| .1
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location of space relative to heated
surfaces;
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| .2
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frequency of cargo
operations;
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| .3
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required surface conditions;
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| .4
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required surface cleanliness and
dryness;
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| .5
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supplementary cathodic protections,
if any (where coating is supplemented by cathodic protection, the coating
shall be compatible with the cathodic protection system);
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| .6
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permeability of the coating and
resistance to inert gas and acids; and
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| .7
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appropriate mechanical properties
(flexibility, impact resistance).
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The coating manufacturer shall supply
products with documented satisfactory performance records and technical data
sheets. The manufacturer shall also be capable of rendering adequate
technical assistance. Performance records, technical data sheet and any
manufacturer's technical assistance provided shall be recorded in the
Coating Technical File.
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Coatings for application underneath
sun-heated decks or on bulkheads forming boundaries of heated spaces shall
be able to withstand repeated heating and/or cooling without becoming
brittle.
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| .2
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Coating type
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Epoxy-based systems.
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| Other
coating systems with performance according to the test procedure in the
annex.
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| A
multi-coat system with each coat of a contrasting colour is
recommended.
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| The top
coat shall be of a light colour to facilitate in-service inspection.
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| Consideration should be given to the use of enhanced coatings in way of
suction bellmouths and heating coil downcomers.
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| Consideration should be given to the use of supplementary cathodic
protection where there may be galvanic issues.
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| .3
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Coating test
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Epoxy-based systems tested prior to the date of entry into force of this
Standard in a laboratory by a method corresponding to the test procedure in
annex 1 or equivalent, which as a minimum meets the
requirements for rusting and blistering, or which have documented field
exposure for 5 years with a final coating condition of not less than "GOOD",
may be accepted.
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| For
epoxy-based systems approved on or after entry into force of this Standard,
testing according to the procedure in annex 1, or equivalent, is required.
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| .4
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Job
specification
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There
shall be a minimum of two stripe coats and two spray coats, except that the
second stripe coat, by way of welded seams only, may be reduced in scope
where it is proven that the NDFT can be met by the coats applied in order to
avoid unnecessary over thickness. Any reduction in scope of the second
stripe coat shall be fully detailed in the CTF.
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| Stripe
coat shall be applied by brush or roller. Roller shall be used for scallops,
ratholes, etc., only.
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| Each main
coating layer shall be appropriately cured before application of the next
coat, in accordance with the coating manufacturer's recommendations.
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| Job
specifications shall include the dry-to-recoat times and walk-on time given
by the manufacturer.
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| Surface
contaminants such as rust, grease, dust, salt, oil, etc., shall be removed
prior to painting. The method to be according to the paint manufacturer's
recommendations. Abrasive inclusions embedded in the coating shall be
removed.
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| .5
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NDFT (nominal total dry
film thickness)footnote
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NDFT 320
μm with 90/10 rule for epoxy-based systems; other systems to the coating
manufacturer's specifications.
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| Maximum
total dry film thickness according to the manufacturer's detailed
specifications.
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| Care
shall be taken to avoid increasing the DFT in an exaggerated way. Wet film
thickness shall be regularly checked during application.
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| Thinners
shall be limited to those types and quantities recommended by the
manufacturer.
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2
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PSP (Primary surface preparation)
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| .1
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Blasting and
profilefootnote,footnote
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Sa 2½;
with profiles between 30-75 μm.
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| Blasting
shall not be carried out when:
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| .1
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the relative humidity is above 85%;
or
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| .2
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the surface temperature of steel is
less than 3°C above the dew point.
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| Checking
of the steel surface cleanliness and roughness profile shall be carried out
at the end of the surface preparation and before the application of the
primer, and in accordance with the coating manufacturer's
recommendations.
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| .2
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Water soluble salt limit equivalent
to NaClfootnote
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 50 mg/m2 of sodium chloride.
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| .3
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Shop primer
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Zinc
containing inhibitor free zinc silicate based or equivalent.
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| Compatibility with main coating system shall be confirmed by the coating
manufacturer.
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3
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Secondary
surface preparation
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| .1
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Steel conditionfootnote
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The
steel surface to be coated shall be prepared so that the coating selected
can achieve an even distribution at the required NDFT and have an adequate
adhesion by removing sharp edges, grinding weld beads and removing weld
spatter and any other surface contaminant to grade P2.
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| Edges to
be treated to a rounded radius of minimum 2 mm, or subjected to three pass
grinding or at least equivalent process before painting.
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| .2
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Surface treatmentfootnote
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Sa 2½ on
damaged shop primer and welds.
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| All
surfaces to be coated shall be blasted to Sa 2, removing at least 70% of
intact shop primer, which has not passed a pre-qualification certified by
test procedures in table 1.3.
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| If the
complete coating system comprising epoxy-based main coating and shop primer
has passed a pre-qualification certified by test procedures in table 1.3
intact shop primer may be retained provided the same epoxy-based system is
used. Retained shop primer shall be cleaned by sweep blasting, high pressure
water washing or equivalent method.
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| If a
zinc silicate shop primer has passed the pre-qualification test of table 1.3
as part of an epoxy coating system, it may be used in combination with other
epoxy coatings certified under table 1.3, provided that the compatibility
has been confirmed by the manufacturer by the test with reference to the
immersion test of annex 1 or in accordance with the Performance standard for
protective coatings for dedicated seawater ballast tanks in all types of
ships and double-side skin spaces of bulk carriers (resolution MSC.215(82)).
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| .3
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Surface treatment after
erection
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Erection
joints St 3 or better or Sa 2½ where practicable.
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For inner bottom:
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| –
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Damages up to 20% of the area to be
coated to be treated to minimum St 3.
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| –
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Contiguous damages over 25
m2 or over 20% of the area to be coated, Sa 2½ shall be
applied.
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For underdeck:
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| –
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Damages up to 3% of area to be coated
to be treated to minimum St 3.
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| –
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Contiguous damages over 25
m2 or over 3% of the area to be coated, Sa 2½ shall be
applied.
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| Coating
in overlap to be feathered.
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| .4
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Profile requirementsfootnote
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In case
of full or partial blasting 30-75 μm, otherwise as recommended by the
coating manufacturer.
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| .5
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Dustfootnote
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Dust
quantity rating "1" for dust size class "3", "4" or "5".
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| Lower
dust size classes to be removed if visible on the surface to be coated
without magnification.
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| .6
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Water soluble salts limit equivalent
to NaCl after blasting/ grindingfootnote
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 50 mg/m2 of sodium chloride.
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| .7
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Contamination
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No oil
contamination.
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| Paint
manufacturer's recommendations should be followed regarding any other
contamination between coats.
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4
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Miscellaneous
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| .1
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Ventilation
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Adequate
ventilation is necessary for the proper drying and curing of coating.
Ventilation should be maintained throughout the application process and for
a period after application is completed, as recommended by the coating
manufacturer.
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| .2
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Environmental
conditions
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Coating
shall be applied under controlled humidity and surface conditions, in
accordance with the manufacturer's specifications. In addition, coating
shall not be applied when:
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| .1
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the relative humidity is above 85%;
or
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| .2
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the surface temperature is less than
3°C above the dew point; or
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| .3
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any other requirements of the paint
manufacturer are not being met.
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| .3
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Testing of coatingfootnote
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Destructive testing should be avoided.
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| Sample
dry film thickness shall be measured after each coat for quality control
purposes and the total dry film thickness shall be confirmed after
completion of the final coat, using appropriate thickness gauges.
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| .4
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Repair
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Any
defective areas, e.g., pinholes, bubbles, voids, etc., shall be marked up
and appropriate repairs effected. All such repairs shall be re-checked and
documented.
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