GAW vs GBW Welded Wire Mesh: Which Galvanising Method Offers Better Corrosion Protection?
GAW vs GBW Welded Wire Mesh: Why the Galvanising Stage Decides Corrosion Protection
When selecting wire mesh for fencing, agricultural, construction, and industrial purposes, durability is a primary concern. The main threat to metal wire mesh is rust. To prevent rust, manufacturers coat the wire mesh with zinc in a process called galvanization.
The stage at which galvanising takes place plays a very important role in the corrosion protection and performance of the mesh. This is where GAW and GBW welded wire mesh differ.
Key Stats & Figures
- Zinc Coating: GAW mesh generally has a heavier zinc coating than GBW mesh, although the exact coating weight varies by wire diameter, manufacturing process, and applicable standard.
- Lifespan Difference: Under outdoor conditions, GAW mesh generally provides a longer service life than GBW mesh because the weld areas receive zinc protection after welding. The actual service life of both types depends on coating thickness, climate, exposure, and maintenance.
- Failure Rate: More than 80% of all cases of early failure of wire meshes outdoors start from the unprotected weld area.
What Do GAW and GBW Mean in Welded Wire Mesh?
GAW and GBW are terms that describe when the wire mesh is galvanised in relation to the welding process.
- GAW (galvanised after welding wire mesh): Steel wires are first welded into a mesh grid and then hot-dip galvanised, allowing the zinc coating to cover the wires and weld areas.
- GBW (Galvanised Before Welding): The individual wires are galvanised first and then welded together to form the mesh grid.
Both are anti-rust coatings, but the difference is in when the galvanising takes place.
How Is GAW Welded Wire Mesh Manufactured?
The production of GAW welded wire mesh follows a very simple galvanising process:
- Bare steel wires are arranged into a grid formation.
- The intersections are then resistance welded to each other.
- The whole mesh is immersed in a molten zinc bath, typically maintained at a temperature of around 450°C.
As a result, the zinc coating covers the wire surfaces and weld areas, providing more continuous corrosion protection across the mesh.
How Is GBW Welded Wire Mesh Manufactured?
GBW welded wire mesh undergoes the following procedure in reverse order:
- Steel wires are first Galvanised/zinc-coated to form pre-Galvanised wire.
- These Galvanised wires are then laid in grid form.
- The wires are resistance-welded at their intersections to form the mesh.
During welding, the heat can damage or remove some of the zinc coating around the weld areas, leaving these points with less corrosion protection than the surrounding wire.
Why Are Weld Points Important for Corrosion Protection?
The heat generated during welding can reduce or damage the zinc coating around the weld points of GBW mesh. These areas may therefore have less corrosion protection and can become more vulnerable to rust when exposed to moisture.
With GAW mesh, the zinc coating is applied after welding, and the zinc spreads over all joints.
GAW vs GBW: Which Offers Better Corrosion Resistance?
The comparison between GAW and GBW welded wire mesh shows a clear difference in the level of corrosion protection provided at the weld points.
Research has shown that continuous hot-dip coating post-welding results in 300% higher outdoor durability than pre-Galvanised and welded methods.
How Do GAW and GBW Perform in Different Environments?
The environmental conditions determine the durability of these materials:
Harsh and Wet Conditions
These include coastal areas, farming regions, and industrial areas where the mesh is exposed to salty water, fertilizer chemicals, and moisture. GAW mesh tends to be superior in such environments because galvanization after welding ensures full coverage of the zinc layer around the welded areas, hence reducing corrosion risks.
Mild Indoor Environments
GBW wire mesh may be suitable for indoor cages, fencing, and agricultural applications where it will not get wet or be exposed to harsh weather conditions.
GAW vs GBW Welded Wire Mesh: Cost and Lifecycle Value
- Initial Cost: GBW mesh is 20%-40% cheaper than GAW mesh, as the pre-Galvanised wire is processed less.
- Maintenance Requirements: GBW needs frequent repainting and repair due to rusting joints. GAW requires no maintenance throughout its lifetime.
- Long-Term Performance: GAW is more efficient than any other alternative for the future. Despite its high initial cost, its long lifespan means fewer replacement expenses.
How to Choose Between GAW and GBW Welded Wire Mesh
To pick the right material, the project specifications should be matched with the surroundings:
- Use GAW for long-term outdoor fencing, animal enclosures, security fencing, and other applications where stronger corrosion protection and longer service life are important.
- Use GBW for budget-sensitive applications, particularly indoors or in environments with limited exposure to moisture and corrosive conditions.
For special industrial uses, there is also the option of using other materials like woven wire mesh, vibrating screen mesh, perforated sheets, expanded metal, and chain link fencing, among others.
In procuring zinc-coated welded wire mesh, consider a trustworthy supplier like Banaraswala to supply you with consistently good-quality coated products, with the suitable mesh size.
Final Verdict: Does GAW Offer Better Corrosion Protection Than GBW?
As far as GAW vs GBW Welded Wire Mesh is concerned, GAW offers excellent protection against corrosion under outdoor conditions and in high humidity due to its galvanised after welding treatment. GBW is economical in less tough conditions.
When choosing, one should take into account the quality of coating, environmental factors, and lifetime, not just the price. For reliable selection, Banaraswala provides high-quality mesh. The initial choice of suitable mesh ensures longevity and low maintenance.
