Metal Coat Gloss Withstands 5,000 Hours of Concentrated Sulfuric Acid

Carbon steel is one of the most widely used structural materials in industry, yet among the most vulnerable to chemical attack. Where concentrated acids, fuels, or hydraulic fluids are present, standard industrial coatings frequently fail, leaving the substrate open to rapid corrosion.

Could a thin-film transparent coating protect carbon steel against one of the most aggressive corrosive agents in industrial use - 87% sulfuric acid - over a sustained period?

A controlled 9-month lab study under ASTM D1308 and ASTM G31. Five carbon-steel specimens were prepared under different surface and coating conditions and subjected to 24-hour spot tests for a cumulative 5,000 hours of acid exposure.

• A - blasted steel, no coating
• B - Metal Coat Gloss over surface rust (37 microns)
• C - Metal Coat Gloss direct-to-metal on blasted steel (37 microns)
• D - industrial paint (60 microns) + Metal Coat Gloss topcoat
• E - industrial paint only (60 microns)

Specimen C (Metal Coat Gloss DTM) delivered the standout result: after the full 5,000 hours, no chemical reaction, no corrosion, no blistering - only a light surface stain, with excellent film-thickness retention. Specimen D (paint + topcoat) also held up with no visible reaction.

At the other end, Specimen A (bare steel) and Specimen E (paint only) failed almost immediately - the paint turned black on contact with penetration to the steel.

• Best: clean-blasted steel + Metal Coat Gloss DTM - zero corrosion at 5,000 hours
• Strong: blasted steel + paint + Metal Coat Gloss topcoat - no visible reaction
• Compromised: coating over rust - failed after 24 hours
• Immediate failure: paint alone and bare steel

Surface preparation was the decisive variable. On properly blasted steel, Metal Coat Gloss at just 37 microns outperformed a 60-micron industrial paint film by a wide margin.