A vessel at a fragrance plant was used for mixing geranoil, acetic acid, and dosing with 50% naoh. the neutralisation of the 50% naoh in the process produces highly corrosive sodium acetate, a soluble salt which in just six years had effectively destroyed a previous epoxy coating and had begun to corrode the vessel itself.
After required welding repairs were completed the entire tank was blast cleaned and then washed to remove soluble salts and then blasted again to a SSPC-SP10 quality. A holding primer was applied to the prepared surface prior to all pits being filled, all edges and transitions being laminated, and stripe coats applied to weld overlay sections. In areas of heavy localised pitting a layer of fiberglass provided increase strength as well as corrosion resistance. Flanges and nozzles were laminated prior to being coated to provide increased protection in these failure prone areas.
On completion of the preparation work the barrier coat (Polyglass VEF) was spray applied to a thickness of 1200µm. After the initial cure an additional coat of Polyglass VEF WR was applied over the barrier coating at a thickness of 600µm.
By using a selection of specialist Corrofill, Polyglass and Corroglass coatings Corrocoat USA was able to return the tank to service fully protected against an aggressive service environment and at a cost far below that of replacement.