Bonderized steel starts as galvanized steel, which is coated with molten zinc to prevent rust. It’s then further processed by a “Bonderizing” treatment—a phosphate bath followed by a chromate conversion coating. This results in a matte gray, textured surface that’s ideal for painting without the need for additional primer.

Key Benefits of Bonderized Steel:

• Pre-primed for paint – ideal for gutters, downspouts, and architectural features.
• Sticky surface allows paint to grip well.
• Saves time and cost – no need for separate priming.
• Especially useful in rainwater systems and residential accents.

Bonderized Steel vs Galvanized Steel

Feature	Bonderized Steel	Galvanized Steel
Surface Finish	Matte gray, paint-ready	Speckled, sponge-like
Paintability	Designed to be painted	Can be painted, but must be primed
Corrosion Resistance	Requires painting to prevent “white rust”	Resists rust without painting
Main Use	Painted finishes	Raw weather protection

The Bonderizing Process

1. Galvanized steel is submerged in a phosphate bath.
2. A zinc-phosphate crystalline coating forms.
3. It’s rinsed and sealed with a chromate layer.
4. Result: a “sticky” texture perfect for paint adhesion—no primer needed.