“All That Glisters Is Not (Bly)gold”

In the world of HVAC, performance is everything. Plant operators, facility managers, and contractors alike depend on reliable systems to deliver heating, cooling, and ventilation efficiently and consistently. Yet, one of the most common—and most overlooked—causes of system inefficiency and failure lies right at the heart of the unit: the coil.

Coils are the lungs of HVAC systems. They are responsible for heat transfer, efficiency, and ultimately the comfort of a building’s occupants. But coils are also fragile and vulnerable. They sit exposed to the harshest elements—salt-laden sea spray, acid rain, airborne pollutants, dust, and chemical attack. Left unprotected, corrosion can set in quickly, reducing efficiency, increasing energy use, and, over time, leading to premature failure.

Protecting coils is therefore essential to maximise asset life and minimise lifecycle costs. But here’s the challenge: not all coil protection coatings are what they appear to be.

As Shakespeare once wrote: “All that glisters is not gold.” Just because a coating looks shiny, smooth, or protective when it’s first applied doesn’t mean it will deliver real-world protection over time.

This blog explores why coil protection matters, how Blygold has become the industry benchmark, and why you should be wary of quick-fix coatings that don’t stand up to the rigours of the environment.

The Problem: Corrosion Is Everywhere

Coil corrosion is not limited to coastal installations, though the effects of salt-laden sea spray are well known. Inland locations face their own challenges, from air pollution (NO₂ and SO₂ leading to acid rain) to particulates and industrial emissions.

Corrosion doesn’t just damage the metal surface—it attacks the thin aluminium fins and copper tubes that are critical for heat exchange. The result?

• Reduced airflow as corroded fins break down or become clogged.
• Loss of efficiency as the coil’s thermal conductivity decreases.
• Higher energy bills as the system works harder to achieve the same output.
• Costly breakdowns requiring coil replacement or even full unit change-out.

Unchecked, what begins as surface corrosion can evolve into galvanic corrosion between dissimilar metals, pitting corrosion within tubes, or total coil failure. This is not just a maintenance headache; it is a financial liability.

The Solution: Protective Coatings

Protective coatings are the frontline defence against corrosion. They act as a barrier between the coil’s delicate surfaces and the environment, preventing corrosive elements from reaching the metal.

But here’s the catch: not all coatings are created equal.

Some look impressive when first applied—thick, glossy, even coloured. They might pass an initial spray or immersion test, but the real world is far less forgiving. HVAC coils are subject to:

• Constant cycles of wet and dry
• Wide temperature swings
• Continuous airflow pulling in pollutants
• Mechanical cleaning during maintenance

Only a proven coating can withstand these conditions for years without cracking, flaking, or losing adhesion.

This is where Blygold stands apart.

Why Blygold?

For over 40 years, Blygold has specialised in HVAC coil protection, and the brand has become synonymous with durability and trust. Unlike generic coatings that are adapted from other industries, Blygold’s PoluAl was engineered specifically for HVAC coils.

Key Benefits:

1. Proven Barrier Protection
   The coating creates a thin, flexible barrier that prevents corrosive agents from attacking the aluminium or copper underneath.
2. Maintained Heat Transfer Efficiency
   Blygold coatings are designed to be thin enough not to compromise airflow or thermal performance—something many competitor coatings can’t claim.
3. Salt Spray Resistance
   Blygold coatings are independently tested against ASTM B117 – 11Salt Spray Tests and exceed industry expectations. Where other coatings fail after a few hundred hours, Blygold consistently delivers thousands of hours of protection.
4. UV and Chemical Resistance
   Whether exposed to intense sun, acid rain, or cleaning chemicals, Blygold coatings hold up in conditions that defeat lesser products.
5. Proven Track Record
   Blygold is used worldwide, protecting coils on everything from data centres and hospitals to oil rigs and airports. This is not an experimental coating; it is the industry benchmark.

“All That Glisters Is Not Gold”

It’s easy to be swayed by a shiny coating. It may look like the coil has been “protected” simply because the surface appears sealed. Some manufacturers or contractors even rely on low-cost sprays that are little more than paint.

In The Merchant of Venice, the Prince of Morocco says the line ““All that glisters is not gold” when he fails to choose the correct casket to win Portia’s hand in marriage.

The line serves to warn against being misled by superficial appearances, as the gold casket he chooses contains a skull.

What matters is not how a coating looks on day one, but how it performs in year five, year ten, or year fifteen. Does it still protect the coil? Has it prevented corrosion? Has it extended the life of the HVAC asset?

Too often, “budget” coatings fail within a short period, leaving coils vulnerable. At that point, the client faces not only the cost of re-coating but also the damage that has already occurred—often irreversible.

Blygold’s coatings, by contrast, have a proven history of longevity. They may not always be the cheapest option upfront, but they deliver the greatest value across the lifecycle of the equipment.

The Cost of Getting It Wrong

Consider the real-world consequences of applying an inferior coating:

• Premature failure: A coil that should have lasted 15 years may fail in less than five.
• Energy waste: Corrosion-induced efficiency losses can add thousands of pounds to annual running costs.
• Disruption: Replacing failed coils or units often requires downtime, which can be disastrous in critical environments like hospitals or data centres.
• Reputation risk: For contractors, specifying the wrong solution can damage client relationships and lead to costly disputes.

By contrast, specifying Blygold ensures peace of mind. The coil is protected. The equipment lasts longer. Energy savings are preserved. And you, as the decision-maker, can demonstrate that you have chosen the industry’s most trusted solution.

Practical Advice for Specifiers and Operators

If you’re considering coil protection, here are three simple rules:

1. Don’t rely on distance from the coast alone – inland sites suffer corrosion from pollutants too.
2. Don’t be fooled by appearance – a coating’s performance is measured in years of real-world service, not how glossy it looks on day one.
3. Choose proven solutions – insist on coatings that pass independent tests and have decades of field data, like Blygold.

Conclusion

In HVAC, asset protection is not a luxury—it’s a necessity. Coils are too important, too expensive, and too vulnerable to be left exposed. Coatings provide the solution, but only if they are the right coatings.

“All that glisters is not gold” reminds us that appearances can be deceiving. Not every coating that looks protective truly is.

With Blygold, you get more than a surface finish—you get proven, long-term protection that extends coil life, preserves efficiency, and saves money.

When it comes to coil protection, don’t gamble on appearances. Trust the gold standard. Trust Blygold.