Corrocoat USA was recently contacted by a leading construction equipment manufacturer to solve a problem that was causing them to shut down their operation one or two times each month.
This manufacturer uses a series of carbon steel tanks to clean, acid etch or “pickle”, galvanize and paint the equipment they produce. The acid etching tanks utilise a mixture of phosphoric acid, hydrochloric acid and process water to prepare steel members for galvanizing. Previously lined with rubber, the tanks were susceptible to failure due to penetration of the acid at the rubber seams or at puncture points.
The acid would then creep behind the rubber, causing corrosion in areas away from the initial access point. Once the failure was discovered, the client had to cut back the rubber to find the corroded steel, cut out the affected area, weld a repair plate and replace the rubber patch. This was a very inefficient and costly process.
The company contacted five leading coating manufacturers with the request that they provide sample plates coated with their product. These were placed in the bottom of one of the tanks and after three months they were removed and subjected to abrasion and impact tests to the point of failure.
Of the five products tested, Polyglass VEF gave by far the best results, so Corrocoat USA was given an order to spray apply this material to the tanks to provide an acid resistant composite lining system.