Edge Corrosion: What It Is and How to Kick It to the Curb

When it comes to homeowner complaints, two rise to the top for us as a metal supplier:

Oil Canning (check out a previous blog here on that topic and some great resources here!)
Edge Corrosion

Let’s talk about the second one.

Edge corrosion. Is it unsightly? Yes. If I were a homeowner and my brand-new project immediately started showing rust on the edges, would I be a little perturbed? Also yes. But here’s the good news: as a supplier, I can tell you edge corrosion is very preventable.

Where It Shows Up

Corrosion usually pops up in two places:

On wall panels set too tight against the double angle
On the eave of roof panels where improper cuts have been made

Both are 100% avoidable — they come down to installation technique.

The Truth About Field Cuts

Field cuts are inevitable on most jobs. What isn’t inevitable? Damage. Using an abrasive saw blade (grinders, etc.) is basically asking for trouble. Not only does it void the manufacturer’s warranty, but it also creates long-term damage. Why? Because abrasive blades heat the metal too fast, and the hot shavings stick to the panel surface and rust almost instantly.

The fix? Use snips, nibblers, or — if you’re ready to level up — invest in a jobsite shear (Swenson makes a solid one). Or better yet, call your supply house. At Indiana Metal, we keep extras on hand for contractors who need more on-site cuts than expected.

Surface Rust on Wall Panels

Another common culprit: wall panels set too close to the double angle, especially with wainscoting. When panels are jammed tight, moisture lingers and rust takes root right at the cut edge. Rule of thumb: leave at least a 1/8″ gap between the double angle and wall panels. That tiny space makes a big difference.

Whether you’re a homeowner, business owner, or contractor, we want your project looking sharp for decades. Got install or product questions? Ask away — we’re here to make sure you get both the product and the outcome you deserve.