Pontoon5TANCO, a tank repair company, specializing in tank construction through technical service, shop fabrication, new above ground tank storage construction, tank maintenance, tank repairs and floating roof seal systems. Since its founding in 1979 by John Mulkey and Sonny Petrie, TANCO has strived to continuously excel in the areas of health and safety performance, work quality, environmental stewardship, and customer service. We earned our top tier industry reputation by consistently delivering results.