How to protect metal in homes and structures near the sea

If you have a house, beach bar, marina, or warehouse near the coast, you already know: metal lasts half as long. The salt carried by the wind settles on the steel, retains moisture, and accelerates corrosion. In the ISO 12944 classification, coastal areas are normally in category C4 or C5, among the most aggressive.

Why normal paint doesn't hold up on the coast

Salt is hygroscopic: it attracts water even on dry days. As soon as the paint has a microcrack, salt water gets in, rust spreads underneath, and the paint lifts. That is why it is so typical on the coast to see freshly painted railings with bubbles the following year.

The solution: zinc + sufficient thickness

Cold galvanizing provides active protection: the zinc sacrifices itself instead of the steel, even if the layer is scratched. Furthermore, GALVANOL is stable in seawater and saline solutions. On the coast, we recommend:

• 3 coats of GALVANOL (about 120 microns dry), which according to ISO 12944-6 tests provide more than 25 years in C4 and 15–25 years in C5.
• Optionally, a solvent-based topcoat, such as ALINOL, for an extra barrier and better aesthetics.

Step by step

1. Wash with fresh water to remove accumulated salt. This step is often forgotten and is key.
2. Remove loose rust and old paint with a steel wire brush or sandpaper.
3. Degrease with xylene and let dry thoroughly.
4. Apply GALVANOL with a brush or roller: 3 coats, leaving 30–60 minutes between coats. Pay special attention to welds, screws, and corners.
5. If you want color or gloss, apply the topcoat after at least 4–6 hours.

Maintenance

Once a year, rinse railings and doors with fresh water, especially after storms. If you see any dent or deep scratch, touch it up with GALVANOL Spray before rust starts.

How much do I need?

A 10-meter railing has about 4 m² of surface area. For 3 coats, it is 4 × 3 × 0.25 = 3 kg of GALVANOL. For your specific case, use the calculator and choose 3 coats.