Corrosion Coating for a Chlorine Plant: A Real-World Trial in Johannesburg, Gauteng
Steel structures inside chlorine processing facilities require a corrosion coating chemical plant environments consistently destroy — one that performs under live operating conditions without hot work or shutdown. Chlorine and its compounds attack conventional coatings rapidly, creating a cycle of failure, recoating and downtime that most facilities accept as unavoidable. This case study documents a trial application of Si-Coat 579CM as a corrosion coating for a chlorine plant in Johannesburg, Gauteng, carried out in April 2025 under live operating conditions.
Location: Johannesburg, Gauteng, South Africa
Industry: Chlorine processing
Environment: Aggressive chemical exposure — chlorine compounds, high humidity, continuous contamination
Product: SI-COAT 579 CM — Traffic White
Application date: April 2025
The Problem: No Coating Could Survive the Chemical Environment
The chlorine plant’s steel structure faced a corrosion challenge that conventional coatings had consistently failed to solve. The aggressive chemical atmosphere — driven by chlorine exposure, high humidity and constant surface contamination — degraded every protective coating applied to the steel structure before it could deliver meaningful service life.
Three constraints made the problem particularly difficult to address. First, no coating previously applied to the structure could withstand the chemical degradation long enough to justify the cost and disruption of application. Second, the hazardous nature of chlorine meant that shutting the facility for hot work was not desirable — safety requirements ruled out any application method requiring open flame, grinding sparks or abrasive blasting. Third, downtime was a critical operational factor. Any solution had to be applied while the plant remained operational, without requiring extended shutdowns or specialist blast cleaning equipment on site.
The client needed a corrosion coating that could be applied cold, without primer, without hot work, and directly onto prepared steel under live plant conditions — and that could withstand continuous chemical exposure without degrading.
The Trial: Corrosion Coating Chemical Plant Application
Rather than committing to a full application immediately, the client requested a controlled trial. TSS recommended applying SI-COAT 579 CM to structural steel in the most aggressive section of the chlorine plant — the area of highest chemical exposure — to determine whether the coating could perform under the worst conditions the facility presented before proceeding with a wider application.
Surface preparation used hand tool and power tool cleaning to remove loose corrosion and surface contamination. No abrasive blasting was required. No primer was applied before the coating. SI-COAT 579 CM in Traffic White was applied directly onto the prepared steel surface in a single coat.
The application required no hot work, no specialist equipment beyond standard brushes and rollers, and no facility shutdown. The plant remained fully operational throughout the application process.
Three Months After Coating: No Degradation
Three months after application, SI-COAT 579 CM showed no signs of degradation in the most aggressive section of the chlorine plant. The coating remained intact, with no blistering, peeling, discolouration or adhesion loss visible on the treated structural columns.
The result confirmed that the coating could withstand continuous chlorine exposure under live operating conditions — a performance standard that previous coating systems had consistently failed to meet at the three-month mark.
Ten Months After Coating: Same Condition as Day One
At the ten-month inspection, the coating appeared to be in the same condition as when it was first applied. No corrosion creep, no coating failure, and no maintenance intervention had been required in the period since application.
The ten-month result confirmed what the three-month inspection had indicated — SI-COAT 579 CM delivers sustained corrosion protection in aggressive chemical plant environments without the repeated failure cycle that conventional coatings generate. The client confirmed the following outcomes from the trial:
Minimum downtime during application. No hot work required at any stage. No primer required before application. No topcoat required after application. No hardener required — single-component, ready to use directly from the container.
Why SI-COAT 579 CM Works in This Environment
SI-COAT 579 CM is a single-component, moisture-cure RTV silicone corrosion maintenance coating developed by CSL Silicones and available exclusively across Sub-Saharan Africa through Technical Solutions Supplies. Its silicone chemistry gives it properties that organic coatings — epoxy, polyurethane, and alkyd systems — cannot match in aggressive chemical environments.
Silicone is chemically inert. It resists sulphuric acid, alkalis, chlorides and industrial chemical contaminants that degrade organic coating binders. Where epoxy films blister and delaminate under chemical attack, silicone maintains its adhesion and flexibility. Where polyurethane systems lose mechanical properties under continuous chemical exposure, silicone retains its elasticity.
SI-COAT 579 CM also remains permanently flexible after cure. Steel structures in chemical plants expand and contract with temperature cycling and vibration from operating equipment. Rigid coatings crack under this movement, creating pathways for chemical attack beneath the film. SI-COAT 579 CM accommodates this movement continuously without cracking.
Because it requires only hand tool or power tool cleaning before application, SI-COAT 579 CM suits facilities where abrasive blasting is impractical, hazardous or prohibited. No hot work. No specialist equipment. No extended shutdown. The same product serves as both primer and finish coat in a single application.
For more information on SI-COAT 579 CM’s performance across corrosion environments in Sub-Saharan Africa, visit our corrosion protection articles: https://www.tssupplies.co.za/category/corrosion-protection/
Key Takeaways from the Chlorine Plant Trial
Chemical resistance is not a standard feature of conventional coatings — it must be engineered into the coating chemistry. SI-COAT 579 CM’s silicone base resists the chlorine compounds and chemical contaminants that destroy epoxy and polyurethane systems.
No hot work and no primer means application is possible in hazardous operating environments where conventional coating work would require facility shutdown or specialist safety measures.
Ten months of zero maintenance in the most aggressive section of a live chlorine plant is a result that conventional coating systems have not achieved at this facility. Real-world field performance, not laboratory data, is the most reliable indicator of corrosion coating suitability.
Frequently Asked Questions
Can a corrosion coating be applied in a live chemical plant without shutting down?
Yes. SI-COAT 579 CM is a cold-applied, single-component coating that requires no hot work, no abrasive blasting and no specialist equipment. It can be applied to prepared steel surfaces while the plant remains operational, making it suitable for facilities where downtime is a critical constraint and hazardous conditions prevent hot work.
Does SI-COAT 579 CM require a primer before application to corroded steel?
No. SI-COAT 579 CM bonds directly to steel prepared by hand tool or power tool cleaning without a primer. Loose corrosion and surface contamination must be removed, but abrasive blasting and primer application are not required. The chlorine plant trial confirmed no primer was used and no adhesion failure occurred over ten months of continuous chemical exposure.
How does silicone outperform epoxy in chemical plant environments?
Epoxy coatings cure rigid and are susceptible to chemical attack from chlorides, acids and alkalis over time. They crack under thermal movement and vibration, creating pathways for chemical ingress beneath the film. Silicone is chemically inert, permanently flexible and resistant to the chemical compounds present in chlorine processing environments. SI-COAT 579 CM maintained its integrity for ten months under continuous chlorine exposure where epoxy systems had previously failed.
What surface preparation does SI-COAT 579 CM require in a chemical plant?
The minimum requirement is hand tool or power tool cleaning to remove loose rust, loose mill scale and surface contamination. The surface must be clean and dry before application. No abrasive blasting, no hot work and no primer application is required. This preparation standard is achievable by standard maintenance crews without specialist equipment, making it practical for in-service chemical plant maintenance.
Is SI-COAT 579 CM suitable for other chemical environments beyond chlorine plants?
Yes. SI-COAT 579 CM resists sulphuric acid, alkalis, chlorides and a wide range of industrial chemical contaminants. It suits structural steel in petrochemical facilities, fertilizer plants, water treatment infrastructure, mining processing plants and any industrial environment where aggressive chemical exposure accelerates corrosion. For a previous case study in a fertilizer plant environment, visit the TSS case studies section.
Where is SI-COAT 579 CM available in Southern Africa?
Technical Solutions Supplies is the exclusive Sub-Saharan Africa distributor for CSL Silicones. SI-COAT 579 CM is available across South Africa, Zambia, Zimbabwe, Tanzania, Namibia, Mozambique and the broader Sub-Saharan region. Contact TSS directly for pricing, technical data and application support.
For more information or to discuss your corrosion protection requirements, contact us: https://www.tssupplies.co.za/contact-us/
For technical questions and product specifications, visit our FAQ page: https://www.tssupplies.co.za/faq/
For more corrosion protection articles and case studies, visit: https://www.tssupplies.co.za/category/corrosion-protection/
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