PPG 02GN084 Chrome-Free Epoxy
Polyamide Primer
Overview and Product
Description
PG 02GN084 is a high-performance,
chemically cured, chrome-free, two-component epoxy polyamide primer designed
primarily for aerospace and industrial applications. Manufactured by PPG
Aerospace (formerly Deft), this primer is formulated to provide robust
protection for metal and composite surfaces, particularly aluminum, without the
use of chromates, making it an environmentally friendlier alternative to
traditional chrome-based primers. It consists of a base component (02GN084) and
a catalyst (02GN084CAT), which are mixed in a 3:1 ratio by volume to activate
the chemical curing process. Once applied and cured, it forms a durable,
adherent film that serves as an excellent base for subsequent topcoats.
This primer is engineered for use
in demanding environments, such as aircraft exteriors and structural
components, where corrosion resistance and chemical durability are critical. It
can be applied over clean, dry, intact aluminum and composite surfaces that
have been pretreated (e.g., with materials conforming to MIL-DTL-5541 or
equivalent). The product is available in various kit sizes, including gallon
kits (GK: 96 oz. base + 32 oz. catalyst, yielding 1 gallon), quart kits (QK: 24
oz. base + 8 oz. catalyst, yielding 1 quart), and touch-up kits (2 oz. or 4 oz.
configurations for smaller repairs). Its chrome-free composition aligns with
modern regulatory trends toward reducing hazardous materials in coatings, while
maintaining high standards of performance.
The primer's chemical curing
mechanism ensures a strong cross-linked structure, offering long-term
protection against environmental degradation. It is typically aqua green in
color (FS#24424), which aids in visual inspection during application, and it meets
stringent military and commercial specifications for aerospace primers.
Key Features
PPG 02GN084 boasts a range of
advanced features that make it suitable for high-stakes applications:
Corrosion Inhibiting: Provides
excellent corrosion protection on metal substrates, helping to prevent rust and
oxidation even in harsh conditions. This is achieved through its epoxy
polyamide chemistry, which forms a barrier against moisture and corrosive
agents.
Chemical and Solvent
Resistant: Highly resistant to a variety of chemicals and solvents, ensuring
the primer maintains integrity when exposed to industrial cleaners, fuels, and
other substances commonly encountered in aerospace maintenance.
Immersion Resistance: Specifically
engineered to withstand immersion in hydraulic fluids, lubricating oils,
phosphate ester-based hydraulic fluids (such as Skydrol), and distilled water
without degrading. This feature is crucial for components in hydraulic systems
or those subject to fluid leaks.
Adhesion and Compatibility: Offers
superior adhesion to pretreated aluminum and composite surfaces, as well as
compatibility with topcoats like those meeting MIL-PRF-85285 and MMS-420
specifications. It promotes strong intercoat adhesion, reducing the risk of
delamination.
Environmental and Safety Benefits:
Chrome-free formulation reduces health and environmental risks associated with
hexavalent chromium. It complies with VOC regulations when used as directed,
though additional thinning may increase VOC levels (consult local regulations).
Application Versatility: Can be
applied via spray (conventional air spray, HVLP, electrostatic), brush, or
roller (for touch-ups). It supports a dry film thickness of 15 to 22.5 microns
(0.6 to 0.9 mils), with theoretical coverage of approximately 19 square meters
per liter (778 square feet per gallon) at 25 microns dry film.
Performance Metrics: Dry film
density of 1.57 grams per cubic centimeter (13.10 pounds per gallon) and dry
film weight of 3.70 grams per square meter at 25 microns (0.00815 pounds per
square foot at 1 mil). These properties contribute to its lightweight yet
protective nature, ideal for weight-sensitive aerospace applications.
Ease of Use: No induction time
required after mixing, with a pot life of 4 hours at 21-25°C (70-77°F).
Viscosity is optimized for spraying (#2 EZ Zahn cup: 20 ± 2 seconds; #4 Ford
cup: 40 seconds maximum).
Specifications and
Qualifications
PPG 02GN084 is qualified to
several industry and military standards, ensuring its reliability in regulated
sectors:
- 5PTMRA01
- MCS 9053 - Type 1 Class 1 Grade
1
- MCS 9053 - Type 1 Class 1 Grade
1 & 2 (Honeywell)
- MCS 9053 - Type 2 Class 1 Grade
1 & 2 (Honeywell)
- MIL-PRF-23377 - Type I Class N
(also referenced as MIL-PRF-23377K Type I Class N in some documentation)
It is recommended to verify the
latest Qualified Products List (QPL) for these specifications, as updates may
occur. The primer is also compatible with topcoat specs like MIL-PRF-85285 and
MMS-420.
Application Instructions
For optimal results, follow these
guidelines:
Surface Preparation: Ensure
surfaces are clean, dry, and intact. Treat aluminum with MIL-DTL-5541-compliant
materials or equivalents. Composites should be similarly prepared.
Environmental Conditions: Apply at
temperatures of 15-30°C (59-86°F) and relative humidity of 20-90%. Ground the
aircraft and equipment to prevent static buildup.
Mixing: Stir the base component
thoroughly (up to 10 minutes if needed), then add catalyst in a 3:1 ratio
(base:catalyst). Mix by hand, shaker, or mechanically for up to 10 minutes. For
touch-up kits, pour catalyst into base cup and shake for 2 minutes. Condition
materials at 13-35°C (55-95°F) for 24 hours prior to mixing. If thinning is
needed, use MIL-T-81772 Type II thinners like IS-237.
Application Methods:
Spray: Use equipment like
conventional air spray (fluid tip 1.1-1.8 mm, air pressure 10-20 psi at pot,
45-60 psi at gun), HVLP (tip 1.0-1.4 mm, pressure 10 psi max at cap),
electrostatic air spray (tip 1.2-1.8 mm, pressure 45-60 psi), or air-assisted
airless (tip 0.009-0.013 inch, pressure 700-1200 psi). Apply in one medium coat
with 50% overlap for uniform coverage.
Touch-Up: Apply via brush or
roller after mixing.
Drying and Curing: Dry-to-touch in
about 30 minutes, dry-to-tape in 2-3 hours, and full cure in 7 days at ambient
conditions. Force curing options are available for faster turnaround.
Cleanup: Use solvents like
MIL-T-81772 Type III or equivalent.
Storage and Shelf Life
Store in a controlled environment
between 21°C and 32°C (70°F and 90°F) to maximize shelf life. Inspect
containers for damage or leaks. Shelf life for unopened can kits is 12 months
from the date of manufacture, while touch-up kits have a 4-month shelf life
from the date of packaging. Always check the product label for exact dates and
adhere to specification requirements for procurement.
Health and Safety Precautions
Handle with care, as the product
contains epoxy resins and polyamides that may cause skin irritation or allergic
reactions. Use in well-ventilated areas with appropriate personal protective
equipment (PPE), including gloves, respirators, and eye protection. Avoid
inhalation of vapors and contact with skin or eyes. In case of exposure, follow
standard first-aid procedures and consult the Safety Data Sheet (SDS) for
detailed hazard information. The chrome-free nature reduces certain risks, but
proper handling is essential to prevent sensitization or other health issues.
This primer represents PPG's
commitment to innovative, sustainable coatings solutions, balancing performance
with environmental considerations for aerospace and beyond.