These guidelines are intended to ensure that products deliver effective protection against corrosion. Obviously, the
efficiency of a coating system requires well-informed product selection and compliance with proper guidelines for
surface preparation and paint application. The achievement of the optimum performance of a coating system depends
largely on the surface preparation and paint application. This responsibility falls primarily on the Contracting Company,
and is not the responsibility of Nippon Paint. Nippon Paint Technical Service Representative fills an advisory role
only, unless otherwise specified in the terms and conditions of the contract. These guidelines are specifically for the
application of Zinky 13 to thoroughly prepared substrates.
The condition of the substrate and application are not within Nippon Paint’s control. Therefore no implied conditions,
warranties or other terms will apply to the product. Nippon Paint does not and cannot warrant the results that the
user may obtain by using the product. In no event will Nippon Paint be liable to the user for any kind of loss (direct
or indirect) even if Nippon Paint was previously advised of it. In line with Nippon Paint’s policy for continuous
development, Nippon Paint reserves the right to modify the product and the information in this data sheet without prior
notice. It is the user’s responsibility to check with Nippon Paint for the latest version of this data sheet. This data sheet
has been translated into various languages. In the event of any inconsistency, the English version shall prevail.
For optimum performance, the use of abrasive grit blasting or an appropriate grit/shot to attain a sharp angular profile
is strongly recommended.
It is advisable to use abrasive blast cleaning to Sa 2½ (ISO 8501-1:2007) or SSPPC-SP10 for optimum performance. If
oxidation has occurred between blasting and application of Zinky 13, it is recommended that the surface be re-blasted
to the specified visual standard. Any surface defects that become apparent during the blast cleaning process should
be ground, filled or treated accordingly. A surface profile of 40-75 microns is recommended. A lower surface profile will
reduce adhesion and may result in mud-cracking.
Shop Primed Steelwork
This product is ideal for un-weathered steelwork freshly coated with zinc silicate shop primer. In the event that the zinc
shop primer shows extensive or widely scattered breakdown, or excessive zinc corrosion products, complete sweep
blasting will be required. Other types of shop primer are unsuitable for overcoating and will require full removal by
abrasive blast cleaning. Weld seams and damaged areas must be blast cleaned to Sa 2½ (ISO 8 501-1:2007) or SSPC
All damaged areas should ideally be blast cleaned to Sa 2½ (ISO 8501-11:2007) or SSPC-SP6. However, small areas
can be power tool cleaned to Pt3 (JSRA SPSS:1984) or SSPC SP11, so long as the area is not polished. Repair of the
damaged area can subsequently be done using a recommended zinc rich epoxy primer such as Zinky 23 or Zinky 22.
All damaged areas should ideally be blast cleaned to Sa 2½ (ISO 8501-11:2007) or SSPC-SP6. However, it is acceptable
that small areas can be power tool cleaned to Pt3 (JSRA SPSS:1984) or SSPC SP11, provided the area is not polished.
Repair of the damaged area can then be carried out using a recommended zinc rich epoxy primer such as Zinky 23 or
Zinky 13 comprises 2 parts, a liquid binder component (Part A) and a Powder (zinc dust) component (Part B).
The Powder (Zinc dust, Part B) should be slowly added to the liquid Binder (Part A) by stirring with a mechanical
agitator. Do not under any circumstances add liquid to powder, as this will result in a heavy, powdery mass filled with
lumps of zinc, thus causing high wastage. The mixed material should then be filtered before application and constantly
agitated in the pot during spraying. Upon mixing, the product should be used within the working pot life specified.
Under normal conditions, thinning of Zinky 13 is not required to obtain good airless spray application properties. At
high temperatures (typically above 28°C (82°F), it may be necessary to thin it with Thinner. The amount of thinning
required will be determined by local prevailing environmental conditions including temperature, humidity, spray method
and so on.
It is recommended that thinning should not exceed 10% by volume. The use of too high a level of thinner or the
incorrect thinner may result in the retardation of the drying and curing processes. Where high levels of thinning are
used, mixed paint should be re-circulated to avoid settling of zinc in the container or in the spray lines.
Working Pot Life Time
Please note that the viscosity of Zinky 13 increases very slowly and the material will remain liquid beyond the pot life
times specified. However, the material should not be applied after the expiry of the pot life to avoid the heightened risk
of poor curing and a tendency to mud-cracking.
Airless spray tips ranging from 0.015” – 0.023”, according to the complexity of the structure to be coated, should be
The total output fluid pressure at spray tip should be not less than 120kg/cm². Excessively high pressure may result in a
‘pock marked’ uneven surface. For spray equipment, available air pressure and capacity should be at least 5.5kg/cm² and
1.4m³/min (80psi) and 50cfm.
Prolonged application of paints containing zinc dust can lead to material accumulating in equipment. Ultimately,
blockages can occur due to being ‘packed out’ with zinc dust. Hence, equipment should be cleaned at frequent intervals
to optimise longevity.
Application by brush or roller is advisable for small areas only. For best results, use an airless spray. Care must be taken to
achieve the specified dry film thickness.
All equipment should be thoroughly cleaned after use.
Environment Conditions For Application
In the event of relative humidity less than 55%, the minimum overcoating time may be extended.
RH at less than 55% RH may result in the retardation of the curing process, in which case it may be necessary to tent
the area and create a suitably warm, humid micro-climate in order to accelerate and complete curing.
Dry Film Thickness
Zinky 13 should be typically applied at 45 – 75 microns dry film thickness, equal to 60 – 115 wet film thickness.
It is critical that Zinky 13 is not over-applied and does not exceed 125 microns dry film thickness on any part of the
substrate in order to eliminate the risk of mud-cracking.
Mud-cracking that is perceptible with normal vision should be rejected, sanded back and touched up.
Dry film thickness should be built up by application in a number of passes.
For areas of low dry film thickness below 45μm, a light sweep blast should be carried out followed by application of
Zinky 13 to specified DFT.
Areas between 45 and 125μm, including overlaps, are considered suitable for general ambient temperature end use.
For high heat service, it is recommended that the DFT is below 75μm.
For areas above 125μm, the area should be re-blasted to Sa 2½ (SSPC-SP6) and the product reinstated to specified
thickness regardless of whether mud-cracking is or is not present.
The stated drying times refer to a single coat applied to produce a dry film thickness of 45 – 75 microns. They have
been calculated under laboratory-controlled conditions at 55% relative humidity. Actual drying times may vary slightly.
Higher levels of relative humidity will result in faster drying times.
The presence of moisture in the atmosphere is integral to the curing mechanism for inorganic zinc silicates. Inadequate
moisture may retard the curing process, and satisfactory curing may not be achieved for several days, if at all.
To determine the degree of cure, a solvent rub test should be performed, as outlined in ASTM D4752 and using Methyl
Ethyl Ketone as the solvent. Satisfactory curing for overcoating purposes is indicated by a value of 44 after 50 ‘double
When topcoats are applied to inadequately cured zinc silicate primers, detachment problems can occur.
Minimum and Maximum Overcoating Interval.
For standard overcoating intervals, refer to the Technical Datasheet. Zinky 13 may be overcoated for an indefinite
period, so long as the surface to be overcoated is intact, clean, dry and free from all zinc salts, zinc corrosion products
and all other contaminants.
To ascertain the minimum overcoating interval for Zinky 13, a solvent rub test should be performed.
Application of tick top coats to zinc silicates that are not fully cured, or over-applied, can lead to splitting problems.
This presents itself as an inability to blast damaged areas back to a sound edge during repair, or eventual adhesion
failure when high build epoxies have caused a high degree of stress in the system. This is responsible for the majority of
zinc silicate system failures.
For other Zinky products, please contact your Nippon Paint representative.