When conducting a coating failure investigation, the investigator’s first inquiries should be “What was supposed to be done,” and “Does it make sense?” The answers to these questions are typically revealed in the specification for the project. However, in this “Case from the F-Files,” there was very little information in the specification to guide the […]
Gas transmission lines are often specified to be coated in a shop using fusion bonded epoxy (FBE) coating systems. These coatings are chosen for the resistance to chemicals, the ease of back filling due to the impact resistance, which also translates to less mechanical damage during the transportation and installation of the pipe sections. One
The Shop Coating Pipeline that Cracked – FBE Coating Read More »
Background of Design Specifications – Five stations of a commuter rail transportation system were exhibiting corrosion and coating adhesion problems. The train stations were constructed approximately six years prior to observed coating failure. The steel surfaces (column covers, wall and ceiling cladding, soffit, security screens and structural support systems) were to receive a porcelain enamel protective
Premature Corrosion of Porcelain Enamel-Coated Panels Read More »
The exterior coating system on six propane tanks was delaminating after only one year of being stored under cover in Mexico. Could the system be repaired? Or was it a total loss? A gas transmission company had all six of the propane tanks fabricated and coated in Mexico for a U.S. facility. The specified surface
The Case of the Compromised Propane Tank Coating Read More »
Concrete Floor Coatings Forensics Case History- Part 2 When examining a coating problem in the laboratory, background information gathered during discussions with the involved parties and information obtained during a field investigation help to direct the course of the laboratory investigation. The background information collected for this case was included in last month’s F-Files, “Concrete
Concrete Floor Coatings Forensics Case History — Part 2 Read More »
This month’s case from the F-Files concerns the application of a high performance liner in a steel demineralized water storage tank, or a demin tank. Demineralized (purified) water can be particularly aggressive in service when even minute traces of soluble salt contamination are present on a coated substrate. Therefore is not uncommon to see soluble
Installation Woes of a Lining in a Demineralized Water Storage Tank Read More »
Chrissy Stewart KTA-Tator, Inc. A senior chemist at KTA-Tator, Inc., Chrissy Stewart is heavily involved in failure analysis using various analytical procedures to determine the cause of premature coating failures. She also creates customized coating material test programs (either compositional or exposure) for individual clients. During her nine-year tenure with KTA, Stewart has acquired SSPC’s
True Detective – Chrissy Stewart, KTA-Tator, Inc. Read More »
What Can Happen When the Service Environment Isn’t Characterized or the Wrong Coating is Selected Fig. 1: This tank lining showed insufficient resistance to the acidic tank contents. Photos courtesy of KTA-Tator, Inc. Typically when a premature coating failure is encountered, it is assumed that either there was a mistake made during the surface preparation
Oops, Wrong Paint! Read More »
At its very basic level, saponification is the term given to the process in which vegetable oils and animal fats are converted into soap. We recognize soaps as wax-like products, modified through the addition of fragrances and skin-care additives (emollients) to become consumer cleaning and bathing products. The essential step in the soap-making process is
Saponification: From Paint to the Grave Read More »
Many important industrial coatings are two- or even three-component products (also referred to as two-pack, 2K, or three-pack, 3K) in which a chemical reaction between the components results in a coating film. The components are packaged separately and require mixing at a specific ratio to form the desired final product. The compositions of the materials
Incorrect Mixing of Multi-Component Coatings Read More »
