Stop Welded Mesh Rust: Coatings Compared

Welded mesh usually fails at one point first: the welds. If you pick the wrong coating for the environment, rust starts there and spreads. This guide compares galvanised, PVC-coated and stainless welded mesh, explains where each belongs, and shows how to avoid the corrosion mistakes that shorten a mesh’s life. You will finish able to match a coating to your site instead of guessing.

Why Welds Corrode First

Welding burns off any pre-applied zinc at the joint and leaves a small heat-affected zone. That bare spot becomes the anode in wet conditions, so rust blooms at the crosses before it touches the straight wires. Any coating decision should be judged by how well it protects those joints, not the flat wire in between.

The Three Main Options

Galvanised (zinc coated)

Two routes exist. Pre-galvanised (galvanised wire, then welded) is cheaper but leaves welds exposed, so it suits dry, indoor or short-life uses. Hot-dip galvanised after welding dips the finished panel, coating the joints and giving a much thicker zinc layer. It is the workhorse for outdoor fencing and agricultural mesh. Zinc also protects sacrificially: it corrodes before the steel, so small scratches self-heal to a degree.

PVC or polymer coated

Here a galvanised mesh is coated in a plastic layer, usually green or black. The plastic seals out moisture and adds a tidy appearance. It performs well until the coating is cut, cracked or nicked; then water gets trapped underneath and corrodes hidden from view. It is excellent for garden, animal and low-abrasion uses, less so where the mesh is bent hard or handled roughly.

Stainless steel

Stainless resists corrosion through its chromium content, not a coating, so cut edges and welds stay protected. Grade 304 handles most outdoor and food-contact uses; grade 316 adds molybdenum for coastal and chemical environments. It costs the most, so reserve it for marine, food, filtration or long-life applications where replacement is expensive or impossible.

Real Example

A coastal aviary was