Evaluation of alternative coatings for U.S. Geological Survey water-quality samplers

Each year, U.S. Geological Survey (USGS) personnel collect approximately 52,000 water-quality samples from rivers and streams across the United States. Several samplers are used by the USGS for water-quality sample collection in riverine environments. These samplers are coated with Plasti Dip to protect the exterior of the sampler; however, Plasti Dip is susceptible to fraying and wear, requiring maintenance. Alternative coatings were tested to determine if a different coating is better suited for the samplers. The alternative coatings included Raptor, powder coating, and DuraCoat; a fifth option was bare metal. Samplers with different coatings were evaluated based on initial coating application, equipment blank samples, a controlled wear test, blank sample collection with worn samplers, maintenance and re-coating of samplers, and field-use and wear tracking. The powder-coated sampler proved to be the top performer overall in the study.