FenceTrac builds its frame system from G90 galvanized steel, which carries 0.90 oz of zinc coating per square foot of steel surface. That is the highest standard zinc coating designation for hot-dip galvanized steel used in fencing applications, and it directly determines how long the frame resists corrosion before any other protective layer is applied.
The Short Answer
G90 is a zinc coating weight specification defined by ASTM A653. It means the steel has been hot-dip galvanized with 0.90 oz of zinc per square foot. Zinc acts as a sacrificial barrier, corroding in place of the underlying steel so the structural metal stays intact.
In fencing, G90 galvanized steel outlasts lighter coatings like G60 or G40 because there is more zinc to sacrifice before corrosion reaches the base metal. When powder coating is applied over G90 galvanization, the two layers work together to extend the frame’s service life well beyond what either layer provides alone.
How Hot-Dip Galvanizing Works
Hot-dip galvanizing immerses steel in a bath of molten zinc at approximately 840 degrees Fahrenheit. The zinc bonds metallurgically to the steel surface, creating a multi-layer coating that is part of the steel rather than just sitting on top of it.
The outermost layer is pure zinc. Beneath it are progressively harder zinc-iron alloy layers that form during the immersion process. This layered structure gives hot-dip galvanized steel better adhesion and abrasion resistance than coatings applied by painting or spraying.
The “G90” designation refers specifically to the weight of zinc deposited. Higher numbers mean more zinc. More zinc means a thicker sacrificial barrier and a longer time before the base steel is exposed to moisture and oxygen.
What the G-Numbers Mean
| Designation | Zinc Coating Weight | Typical Use |
|---|---|---|
| G40 | 0.40 oz/sq ft | Interior ductwork, light-duty enclosures |
| G60 | 0.60 oz/sq ft | Structural supports, general outdoor use |
| G90 | 0.90 oz/sq ft | High-exposure exterior applications, fence frames, agricultural structures |
| G115 | 1.15 oz/sq ft | Heavy industrial, marine environments |
FenceTrac uses G90 galvanized steel for its entire structural system: the horizontal top and bottom rails, vertical side rails, and posts. Every steel component that bears wind load or physical stress on the fence carries the same G90 zinc coating weight.
Posts are embedded in concrete footings, so the combination of G90 galvanization, powder coating, and concrete encasement at the ground line gives the most vulnerable point on the fence three layers of corrosion protection.
Why Zinc Coating Weight Matters for Outdoor Fencing
A fence frame sits outdoors in direct contact with rain, humidity, freeze-thaw cycles, and UV exposure year-round. Without adequate corrosion protection, steel begins to rust at the surface and progressively weakens.
Zinc corrodes at a predictable rate depending on the environment. In a typical suburban setting, G90 galvanized steel loses roughly 0.05 oz of zinc per square foot per year. At that rate, the zinc layer on a G90 frame lasts approximately 18 years before the base steel is exposed, even without any additional coating.
In coastal or industrial environments where salt air or chemical exposure accelerates corrosion, zinc depletes faster. That is where the combination of G90 galvanization plus powder coating becomes critical.
How Powder Coating Works with Galvanization
FenceTrac applies a powder-coated finish over the G90 galvanized steel frame. Powder coating is a dry finish applied electrostatically and cured under heat, forming a hard, uniform surface that is more durable than conventional liquid paint.
The powder coat serves as the first line of defense against moisture, UV, and physical abrasion. It keeps water and oxygen from reaching the zinc layer underneath.
If the powder coat is scratched or chipped, the zinc layer takes over. The exposed zinc corrodes preferentially, protecting the steel beneath. This two-tier system means a scratch that would cause rust on uncoated steel simply exposes the zinc sacrificial layer on a FenceTrac frame.
Together, the G90 galvanization and powder coating give the FenceTrac frame corrosion protection that outlasts what most fence manufacturers offer. Standard colors are Black, Bronze, White, and Silver.
How G90 Compares to Other Fence Frame Materials
Most conventional metal fence posts and rails use thinner galvanization or rely on paint alone. Chain link fence posts, for example, are commonly G40 or G60 galvanized. The lighter coating is adequate for the thinner gauge tubing used in chain link but would not provide the same protection on a privacy fence frame that faces higher wind loads and surface exposure.
Aluminum frames do not require galvanization because aluminum does not rust. However, aluminum is a softer metal with lower structural strength per cross-section than steel. FenceTrac uses steel for the frame precisely because it provides greater rigidity and load-bearing capacity, then protects it with G90 galvanization and powder coating to match or exceed the corrosion resistance of aluminum.
Wood posts require no galvanizing, but they face their own durability problems: rot, pest damage, warping, and ground-line failure. A FenceTrac privacy fence system with a G90 steel frame eliminates all of those failure modes.
Related Questions
What does G60 mean on fence posts? G60 indicates 0.60 oz of zinc per square foot, a common specification on chain link and lighter-duty fence posts. FenceTrac uses G90 for both its frame and posts, providing 50% more zinc coverage than a G60-rated product.
Does galvanized steel rust? Eventually, yes, if the zinc coating is fully depleted. G90 galvanization provides approximately 18 years of bare zinc protection in a typical outdoor environment. With powder coating applied over the zinc, the effective corrosion resistance extends significantly further.
For full frame and infill specifications, visit the FenceTrac specifications page.
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FenceTrac has been manufacturing engineered fence systems in the USA since 2012.
Every system carries a 20-year warranty and is engineered for long-term performance with minimal maintenance.