Understanding Why Corrosion is Severe in Africa

Corrosion is a natural process that results in the degradation of materials, particularly metals, through chemical reactions with their environment. In Africa, this phenomenon presents unique challenges that result in higher rates of corrosion compared to other regions. The factors contributing to severe corrosion in Africa are multifaceted, including environmental conditions, socio-economic factors, and material usage.

Environmental Factors

One of the primary reasons for the accelerated corrosion rates in Africa is the continent's diverse climatic conditions. High humidity levels, particularly in coastal regions, create an ideal environment for electrochemical reactions that lead to corrosion. For instance, cities along the coast in Africa experience high saline aerosols from the ocean, which enhance corrosion rates on metallic structures due to the combined effects of moisture and salt.

Furthermore, the presence of acidic soils in various regions, often due to industrial activities or natural minerals, exacerbates the issue. The chemical properties of these soils can react with metals, leading to pitting and overall faster deterioration. Additionally, factors such as temperature fluctuations—common in many African climates—can induce stress on materials, accelerating corrosion processes.

Industrial and Economic Context

The economic landscape in many African countries plays a critical role in the management of corrosion. Limited resources and insufficient infrastructure often lead to inadequate maintenance of metallic assets. For example, aging infrastructure, such as bridges, pipelines, and buildings, is prevalent in several regions but lacks proper inspection and maintenance schedules. The neglect of timely maintenance leads to cumulative damages that increase vulnerability to corrosion.

Investments in advanced protective coatings and materials, which are commonly used in developed nations to mitigate corrosion, are often lacking in many African economies. The high cost of these technologies can deter both public and private entities from implementing proactive measures against corrosion. Additionally, the lack of awareness regarding corrosion's implications and management strategies contributes to its prevalence.

Material Selection and Usage

The choice of materials used in construction and manufacturing significantly impacts corrosion rates. In many parts of Africa, there is still a reliance on materials that are not corrosion-resistant, particularly in rural areas where cost constraints prevail. For instance, the use of uncoated carbon steel for water supply systems in regions affected by high humidity and salinity dramatically increases corrosion risks.

Furthermore, the practice of recycling and repurposing old metals without proper treatment or coating leads to corrosion problems. Many industries may prioritize cost over quality, resulting in the use of substandard materials that corrode more quickly. Awareness and training on selecting appropriate corrosion-resistant materials are essential in addressing this issue.

Impact on Infrastructure and Economy

The consequences of severe corrosion in Africa are significant, affecting both infrastructure integrity and economic stability. The failure of critical infrastructure due to corrosion can lead to direct financial losses, interruptions in services, and increased safety hazards. For instance, the collapse of bridges or the failure of water supply systems can cause catastrophic consequences, straining governmental resources and impacting local communities disproportionately.

Consequently, the economic burden of corrosion can be extensive. It is estimated that global corrosion costs tens of billions annually, and while comprehensive statistics specific to Africa are scarce, it is reasonable to surmise that the impact is similarly substantial. Investments in preventive maintenance, industrial maintenance and protective coatings, corrosion-resistant materials, and education about best practices could ultimately save significant amounts in repair costs and reduce economic losses.

Are They Stopping Corrosion for Good?

While no coating offers ever-lasting protection, high-quality moisture-cure coatings can extend a structure's corrosion resistance by decades, especially when combined with good industry practices like surface preparation and environmental monitoring, they significantly reduce maintenance costs and downtime.

The Future of Corrosion Control in Africa's Diverse Climatic Conditions with Moisture-Cure Coatings

Introducing the Polyval and Xymax range engineered for Africa:

Max Coat HB is a semi-gloss single-component aliphatic moisture-cure polyurethane topcoat. Outstanding exterior weathering performance, achieving the technology's highest level of color and gloss retention, abrasion resistance, and physical property toughness.

• Can be applied in damp cold, humid, or foggy conditions
• Can be applied by brush, roller, or spray
• Excellent gloss and color retention
• Excellent abrasion resistance
• Excellent chalk resistance
• Non-yellowing
• Can be applied at a minimum of -7°C (20°F) and humidity up to 99%; no dew point temperature differential restrictions
• Low dirt pick-up or staining
• pH range 2 to 12
• Can achieve a high-film build of 4 mils DFT by spray application

Mono Ferro PUR is a micaceous iron oxide (MIO)-pigmented, one-component, moisture-cure polyurethane used as a primer, intermediate coat or "overcoat" over aged alkyds, vinyls or epoxies. Can also be applied over SSPC-SP-2, SP-3, SP-6, SP-11 or SP-13 surface preparations. May also be used as a non-light-stable topcoat.

• Use as a spot or full primer.
• Can be applied in damp, cold, humid, or foggy conditions.
• Can be applied directly to steel, aluminum, galvanized metal or concrete.
• Can be applied at a minimum of -7°C (20°F) and humidity up to 99%, no dew point temperature differential restrictions.
• Excellent adhesion properties to tightly adhering rust.
• For use as field touch-up over inorganic zinc.
• Quick recoat times.
• Does not become brittle with age.
• Use as an interior topcoat.
• No pot agitation required
• pH range 3 to 11
• Intermediate coat over Xymax Mono Zinc ME III, Mono Zinc, Mono Zinc 390, Mono Lock PP, Xyguard or itself

MONO GUARD is a highly refined coal tar/micaceous iron oxide (MIO), one-component, moisture-cure polyurethane for use on primed steel, bare steel, or concrete in areas exposed to partial or constant immersion in salt or fresh water at ambient temperatures. MONO GUARD has good solvent, abrasion, and chemical resistance.

• Excellent adhesion directly to SSPC-SP-10 or SP-6 blasted steel, Mono Zinc primers, or concrete
• Excellent mechanical damage resistance
• Coal tar is refined; it has less odor than coal tar epoxy
• Can be applied by brush, roller, or spray
• pH range 4 to 11
• Can be applied in damp, cold, humid, or foggy conditions and at a minimum of -7°C (20°F) and humidity up to 99%; no dew point temperature differential restrictions.

MONO ZINC ME III is a Zinc-pigmented, one-component, moisture-cure polyurethane primer. For use as a high-performance primer for hot-rolled or galvanized metal, as a fast-dry shop primer, or, in the field, as a primer for Xymax intermediate or topcoats.

• 83% minimum weight of zinc in dry film
• Meets SSPC Paint 40
• For the protection of steel or galvanized metal
• Weldable primer
• Can be applied in damp, cold, humid, or foggy conditions
• Can be applied at a minimum of -7°C (20°F) and humidity up to 99%, no dew point temperature differential restrictions
• For use as a field touch-up over inorganic zinc
• Cures in less time than two-component conventional primers and epoxies
• No pot agitation required
• Smooth, dense finish; no bubbling when topcoats are applied
• pH range 4 to 11

MONO ZINC 390 is a Micaceous iron oxide (MIO)/zinc-pigmented, one-component, moisture-cure polyurethane primer. For use over steel or weathered galvanized metal, or as a spot primer for marginally cleaned or blasted surfaces.

• 65% minimum weight of zinc in dry film
• Can be applied in damp, cold, humid, or foggy conditions
• Can be applied at a minimum of -7°C (20°F) and humidity up to 99%, no dew point temperature differential restrictions
• Mixture of MIO/zinc for high-corrosion performance.
• Quick recoat times
• Cures in less time than two-component conventional primers and epoxies
• Does not become brittle with age
• No pot agitation required
• Can be used as a spot primer over hand or power-tool-cleaned, previously painted surfaces
• pH range 4 to 11

XYGUARD is a high-build (4 to 6 mils DFT) single-component moisture-cure polyurethane serving as an all-purpose primer, intermediate coat or interior topcoat. XYGUARD is surface-tolerant and provides excellent corrosion, abrasion and water resistance.

• Excellent adhesion to steel, aluminum, galvanized metal, weathering steel, concrete, fiberglass or old coatings
• Excellent adhesion to marginally prepared surfaces
• Excellent over-aged alkyds or epoxies
• Excellent abrasion resistance and chemical resistance for splash and spill areas
• Quick recoat times in cold, damp, humid, and foggy conditions
• Suitable for early immersion or splash areas
• Cannot amine blush; does not become brittle with age
• Can be applied at a minimum of -7°C (20°F) and humidity up to 99%; no dew point temperature differential restrictions
• Achieves 6 mils DFT per coat
• Apply by brush, roller, or spray
• Good topcoat for interior use
• Can be applied over SSPC-SP-2, SP-3, SP-11, SP-6, or SP-10 steel surface preparation.