Blog | Legacy Building Solutions

Fighting Corrosion: Hot-Dip Galvanizing vs. EpoxxiShield™

Written by Legacy Building Solutions Marketing | Aug 21, 2020, 3:27:37 PM

We’ve seen the effects of corrosion on many steel buildings, and one thing is for sure: hot-dip galvanizing (HDG) doesn’t prevent corrosion. It just delays it for a few years.

In fertilizer plants, salt sheds, and mining facilities, the zinc coating that protects hot-dip galvanized steel wears through in five to seven years. When it does, the bill comes due: new steel, lost production time while crews demolish and rebuild, and product contaminated by rust flaking into stored materials.

That’s why we started moving away from HDG for corrosive environments years ago. In our view, EpoxxiShield™ offers a better solution.

EpoxxiShield™: A Barrier, Not a Sacrifice

HDG works by sacrifice: the zinc coating corrodes so the steel doesn't have to, at least until the zinc runs out. EpoxxiShield™, our proprietary epoxy coating system, instead forms a continuous barrier between the steel and whatever is trying to corrode it—dust, chemicals, salt, moisture—so nothing reaches the metal in the first place.

Two details separate HDG from EpoxxiShield™ coating:

  • No holiday pinholes. Galvanizing baths can leave microscopic gaps in coverage, exposing bare steel when the building goes up. An EpoxxiShield™ multi-coat application closes those gaps.
  • No edge exposure. HDG coating thins at welds, cut edges, and connection points. EpoxxiShield™ epoxy layers are applied to protect those vulnerable points as thoroughly as flat surfaces.

We didn't take this on faith. An independent lab exposed EpoxxiShield™ COR and HDG samples to more than 2,000 hours of continuous salt fog. The EpoxxiShield™ samples showed 0.01% or less surface corrosion. The HDG samples showed rust across 1% to 10% of the surface.

Read full study: EpoxxiShield™ vs. Hot-Dip Galvanizing: Corrosion Protection Performance Data

We also back the frame and finish with a 15-year warranty, and our buildings are engineered to perform even longer than that.

For Fertilizer Storage

There's a lot of chemistry happening in the fertilizer storage facilities we build. Conveyors, mixing towers, and constant dust create conditions that wear away steel fast. Fertilizer dust is particularly corrosive, and it attacks steel both chemically and physically. EpoxxiShield™ creates a barrier against both.

For Salt Storage

Anyone in the snow belt knows salt and rust travel together. Cities, counties, and states that store road salt need to keep it out of the weather while protecting the steel structure around it. We've been building salt storage structures for years, and we've learned a lot about keeping a frame protected against constant salt exposure.

For Mining Sites

Mine site chemicals are especially corrosive—we saw this firsthand with a salt mine in Kansas. We first started testing epoxy coatings at that Kansas site. Later, in Chile, we built a storage structure for copper concentrate, a material that reacts chemically with the zinc in galvanized coatings. HDG isn't even an option there; EpoxxiShield™ is.

When you buy a storage building, you're buying for decades, not years. Our buildings pair the toughest PVC cladding available with a solid steel frame protected by an EpoxxiShield™ coating built for the environment.

Start your project by contacting our team. We’ve got you covered.