Problem Solving Forum


July 26 - July 30, 2021

On guardrails on a marine wharf, grating panels consisting of mild steel bars about 1/8-inch by 1-inch on a 2-inch-square grid were painted with a three-coat zinc/epoxy/urethane system. Inspectors are finding numerous pinholes in the finish coat along the inside corners of the grating where the 1-inch-thick bars meet at a 90-degree angle. These pinholes were not noticed in the zinc or epoxy coats, but the final coat's visual inspection is more detailed. What is the likely cause of the pinholing, and what could be done to prevent it on future applications? Also, what should the disposition of the parts with pinholes be, as in, repair, accept as is, reblast and recoat, or an alternative?


Selected Answers

From Neil Pittman of Lake Superior Consulting on July 27, 2021:
My first instinct is to jump to conclusions and sa ...read more

From Mahendra solanki of abc on July 27, 2021:
If there are use inorganic zinc silicate primer an ...read more

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Tagged categories: Asia Pacific; EMEA (Europe, Middle East and Africa); Latin America; Maintenance + Renovation; North America; pinhole