THE PROBLEM
Following the lining of the glass fused to steel tank by ourselves remediation of the tank externals was required to prevent further degradation and corrosion.
Glass Fused to Steel Tank Protective Coating
THE SOLUTION
Glass fused to steel is an extremely difficult surface to adhere to, therefore we proposed a coating system that will even adhere to glass – Rustoleum Noxyde.
Initially areas where the epoxy adhesive we had used to bond steel plates internally had protruded were sanded flush. This was followed by the high pressure washing of the tank to remove contaminants.
Exposed steel was prepared to ST2 as per ISO8501 -1 in line with the manufacturers recommendations.
As part of our standard protective coating quality assurance soluble salt tests were conducted to confirm that levels present were within the manufacturers recommendations.
Soluble salts if left in place draw moisture through a coating film, which contrary to common knowledge are a semi permeable membrane. This osmotic action then creates a fluid filled blister under the protective coating film. This is something many other protective coating applicators often overlook.
Prior to coating application and during climatic conditions were tested and recorded, again as part of our standard quality assurance.
An Initial stripe coat of Rustoleum was applied to all nuts, bolts, angles and edges. One of the key benefits of Rustoleum Noxyde is its excellent edge retention properties.
A full coat of Rustoleum Noxyde was then applied at a practical coverage rate of 0.5Kg/m2. In line with the manufacturers recommendations this was diluted with clean water to promote adhesion to the glass fused to steel substrate.
During coating application as per best protective coating application practice frequent wet film thickness readings were taken using wet film thickness combs.
Another feature of Rustoleum Noxyde that made it particularly suitable for this protective coating application is its 200% elongation properties. Glass fused to steel tanks of this bolted construction have the potential to expand an contract up to 1mm on the vertical joints.
Dry film thickness readings were taken, subtracting the original glass fused to steel thickness to determine that the correct protective coating film thickness had been achieved. Any areas below thickness were marked and additional thickness applied.
To match the original tank colour Rustoleum Metal cladding Top Coat was then applied in the specified RAL colour to a dry film thickness of 50 microns.
