What Is Galvanizing
Understanding Galvanizing
Galvanizing involves coating iron or steel with zinc to protect it from rust, oxidation, and environmental wear, especially effective when steel has been properly
B.B. Price uses their own in-house shot‑blasting first (or chemical cleaning) to remove dirt, grease, rust and mill scale, which is essential to ensure proper adhesion of the zinc coating.
They typically use hot dip galvanizing: steel is submerged in a bath of molten zinc heated to approx. 450 °C (842 °F), resulting in a robust, metallurgical bond between zinc and steel.
After immersion (often around 5 minutes), the coated metal is quenched in water or allowed to air‑cool, and then inspected for quality.
Galvanizing: The Process
Galvanizing is the process of coating steel or iron with a layer of zinc to protect it from rust and corrosion.
The most common method and also the method we use is called hot dip galvanizing, which works like this:
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Clean the steel - The metal is cleaned (usually by shot blasting or chemical treatment) to remove dirt, oil, and rust.
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Dip it in molten zinc – The clean steel is dipped into a bath of molten zinc at about 450°C.
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Zinc bonds to the steel, then the zinc reacts with the steel to form a tightly bonded alloy coating.
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Cool and inspect. The coated steel is cooled and checked to make sure the zinc layer is even and protective.
What does the zinc coating do?
1. Barrier Protection
The zinc coating acts as a physical shield between the steel and the environment.
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It blocks moisture, oxygen, and chemicals from reaching the steel surface.
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As long as the zinc layer stays intact, rust can’t form on the steel underneath.
2. Sacrificial Protection (Galvanic Action)
Even if the zinc layer is scratched or damaged, the zinc will still protect the steel nearby.
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Zinc is more reactive than steel, so it will corrode first.
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This means it “sacrifices” itself to keep the steel from rusting.
Result:
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The steel stays protected even when the coating is damaged.
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This makes galvanizing much more effective than just painting or coating steel with non-reactive materials.
Key Features of B.B. Price’s Galvanizing:
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In-House Shot Blasting & Galvanization
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They clean and coat the metal on-site.
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This gives them full control over quality and speeds up turnaround time.
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High-Quality Zinc Coating
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Their cleaning (shot blasting) process ensures the zinc sticks well.
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Results in a long-lasting finish that resists corrosion.
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Very Long Lifespan
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Properly galvanized items can last up to 100 years in mild environments.
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Even in tough conditions (coastal or industrial), it lasts decades.
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Customizable for Different Products
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They can galvanize anything from small parts to 6-meter sections.
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Offer hot-dip and brush finishing — useful for threaded or intricate parts.
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Built for Harsh Environments
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Ideal for products used in agriculture, industry, and coastal areas.
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Offers reliable, sacrificial corrosion protection (zinc corrodes before steel).
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Fast and Efficient
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Everything is done internally, so lead times are faster and quality is consistent.
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Eco-Friendly
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Galvanizing is a sustainable method.
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Reduces the need for constant repainting or part replacements.
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What Is the Hot-Dip Galvanizing Method?
Hot-dip galvanizing is a process where clean steel is immersed in molten zinc at about 450°C (842°F). This creates a strong, corrosion-resistant coating that bonds with the steel itself.
Step-by-Step Process:
1. Surface Preparation
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The steel is first cleaned thoroughly using:
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Degreasing - removes oils or grease.
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Pickling (acid bath) - removes rust and scale.
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Rinsing - clears away residues.
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This step is crucial for proper zinc bonding.
2. Fluxing
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After cleaning, the steel is dipped in a flux solution (usually zinc ammonium chloride).
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This prevents the steel from oxidzing before galvanizing and helps the zinc stick better.
3. Hot-Dip Galvanizing
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The steel is immersed in molten zinc, heated to about 450°C (842°F).
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The zinc reacts with the iron in the steel to form a series of zinc-iron alloy layers.
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These layers are metallurgically bonded, not just surface-coated.
4. Cooling & Finishing
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After being removed from the zinc bath, the item is cooled (in air or water).
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Excess zinc is drained, and the surface is inspected for uniformity and coverage.
Key Benefits of Hot-Dip Galvanizing:
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Tough and durable - the alloy layer is hard and resistant to impact.
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Long-lasting protection - often 50–100 years depending on environment.
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Self-healing - zinc continues protecting exposed areas via sacrificial action.
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Full coverage - inside, outside, corners, and threads are all coated.
Disadvantages of Galvanizing and how B.B Price Minimises them
While galvanizing offers excellent corrosion protection, it’s important to be aware of some limitations:
Size Limitations
- Hot dip galvanizing tanks have maximum size capacities. At B.B. Price, we can galvanize products up to 4 metres long, which may not accommodate oversized structures.
- Our solution: We offer brush galvanizing for components like threaded screws and can advise on modular designs that fit within size limits.
Surface Appearance
- Galvanized finishes may have a mottled or uneven appearance, which may not meet visual or aesthetic expectations for architectural applications.
- Our solution: We ensure consistent surface preparation with in-house shot blasting, improving both adhesion and surface uniformity.
Not Ideal for All Metals
- Galvanization is typically suited to steel and iron. It’s not appropriate for some other metals, such as aluminum or copper.
- Our solution: We provide expert advice on material selection and can recommend alternative coatings if galvanizing isn’t appropriate.
Potential for Warping
- Thin or asymmetrical steel sections can distort during the high-temperature hot-dip process.
- Our solution: We advise on material design and thickness during the planning stage to avoid distortion issues.
Initial Cost vs. Paint
- Galvanization may have a higher upfront cost compared to basic paint coatings.
- Our solution: This process offers far greater long-term savings due to its extended service life and minimal maintenance requirements.
does galvanized steel corrode?
1. Zinc corrodes instead of steel
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The zinc coating protects the steel by acting as a sacrificial layer.
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As long as any zinc remains, it will corrode first, keeping the steel underneath safe.
2. Corrosion happens when:
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The zinc layer wears away over time, especially in:
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Coastal areas (saltwater is very corrosive)
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Industrial environments (acidic or polluted air)
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Wet or damp conditions with poor drainage
- Once the zinc is gone in a specific spot, the steel underneath is exposed and may begin to rust.
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3. Surface damage
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If the galvanized coating is damaged (deep scratches, cuts, drilling), and the exposed area is large enough, corrosion of the steel may begin especially if the surrounding zinc can’t offer protection to the bare steel.
Benefits of Galvanizing
- Lower cost than getting stainless steel
- Far less maintenance required once galvanized
- There is a lower long-term cost due to longer life expectancy
- Coating performance and life are reliable
- Galvanizing provides outstanding resistance to mechanical damage
- It is the toughest form of metal protection
- Gives a complete and reliable form of protection
- Provides an ease of inspection
All of these benefits highlight that galvanizing is a process that can add to your product and give better levels of protection overall.
Why Choose B.B. Price?
For over 100 years, B.B. Price has been a leading metal fabricator in the UK, delivering high-quality, precision-engineered products across various industries. Our team of expert fabricators is fully certified and skilled in working with materials up to 12 metres in length. Whether you need standard steel components or custom-made fabrications, we have the expertise and technology to meet your needs.
What IS Galvanizing: Get Your Free Quote Today
B.B. Price is your trusted Galvanizing specialists. Based in Halesowen in Birmingham, we provide custom services across the country, from London and Nottingham to Manchester and beyond.
Whether you need small fittings, stainless steel components, or large-scale components, we’ve got you covered. Contact us today for a consultation and let B.B. Price bring your project to life with precision and accuracy.