Coatings & Linings

Award-Winning Water Tower Welcomes All to Fort Lauderdale

The tower’s future looked bleak, but it was saved when local residents were successful in rallying for its restoration instead. Now, the colorful and newly coated tower welcomes everyone to the coastal Florida city.

Recoating a Symbol of a City

The “Spoonbridge and Cherry” is an iconic sculpture in Minneapolis, Minnesota. Recently, concern was expressed over the condition of the cherry and its coatings. The cherry was inspected, removed, and recoated. This article describes the rehabilitation process and the materials used.

Corrosion Control Technologies for Wastewater Treatment Plants

Wastewater treatment plant components generally experience both atmospheric and immersion corrosion. Hydrogen sulfide (H2S), which is usually present, has wide-ranging effects in wastewater systems, most notably causing corrosion and odor problems. The corrosion problems can be mitigated by a combination of strategies including judicious selection and implementation of emerging corrosion-resistant coatings.

Role of Nonmetallic Composites in Gas Plants

Several factors cause deterioration of critical process equipment in process plants. The options widely utilized for restoration include conventional repair or replacement. Nonmetallic composite materials can be utilized as an option to restore equipment integrity. This article discusses the material degradation aspects in critical streams such as the cooling water system and hydrocarbon pipelines at a Saudi Arabian gas plant. Nonmetallic composite coating materials play a vital role in corrosion protection and life extension of core components.

Service Life Extension for Protective Coatings

Because of increasing costs, owners are demanding longer coating service life. Ten to 15 years is no longer satisfactory. Simply adding dry film thickness will not work since many coatings crack at excessive thicknesses. Recent coating technology advances permit the use of solvent-free epoxy and polyurethane systems having >15-year lives. Newer combinations of epoxy and polysiloxane resins will make a 25-year life achievable.

Fluoropolymer Lining for a Chlorine Scrubber

A chlorine scrubber fabricated from fiberglass-reinforced plastic (FRP) was installed in 1977. Major repairs began in 1981 and continued at four-year intervals. After exploring several replacement materials, a FRP/ethylene-chlorotrifluoroethylene dual laminate scrubber was selected. This was installed in 1987 and remained in continuous service until the plant shut down in 2001. Examination shortly after plant closing showed the liner to be in excellent condition.

The Importance of the Pre-Job Meeting

A thorough pre-job meeting is an essential part of any project. This article covers the requirements of a pre-job meeting before starting a coating project. It presents advice on who should attend, the roles of the attendees, and references needed.

Premature Coating Disbonding on Ships and Offshore Structures

Epoxy/urethane coating systems are widely used for ships and offshore structures because of their excellent resistance to ultraviolet radiation and protection against corrosion. Recently, some of these coating systems used in Korea experienced premature failure. This work investigated the root cause of the failures using pH tests and Fourier transform infrared spectroscopy.

Long-Term Performance of a Fluoropolymer- Lined Process Vessel

An ethylene chlorotrifluoro-ethylene (ECTFE) lining of a process vessel handling alkaline-based fluids and active chlorine was examined after more than 23 years of service. The examination and tests showed that the ECTFE material was undamaged. Test procedures, data evaluation, and conclusions are presented.

Application of Organic Coatings

Organic coatings include latex paints, plastics, asphaltic materials, rubbers, and elastomers. The specific material selected for a coating job must have characteristics that would allow its proper application under all conditions existing during the coating process. Proper identification of the physical or other properties of the film expected from the application must be specified.

Restoration of a Brick Chimney with a Dual Lining System and Polymer Concrete

A brick flue at a generating station was in need of rehabilitation because of the spalling and cracking of the brick. This caused a leakage of acid gases into the annulus. A typical flash coat system was not desired because of its relatively short life. A system of corrosion-resistant materials, which has shown excellent performance and durability, was chosen to make the repairs. The system consists of a combination of organic and ceramic-based lining materials. A case history is presented, with descriptions of the operating environment and materials selection criteria.

Importance of the ‘Little Things’ in a Good Coating Job

Many years ago, early in my career, I was reminded that it’s the little things that make a standard paint job a good paint job. Coatings are too often thought of as something that must be done, but it’s not necessary to spend much time on surface preparation or application. After all, “paint is paint and anybody can apply paint.”

Di-Octyl Sebacic Acid in Epoxy Paint Leads to Blistering in a Drum and Barrel Manufacturing Plant

Di-octyl sebacic acid (DOS-A) is used as rust preventive oil on steel sheets. When applied below the maximum level of 75 mg/m2 per side, it is compatible with epoxy paint and does not require any pretreatment of the steel sheets. The incompatibility of DOS-A above this maximum could be caused by weak H-bonding between the acid and epoxy molecule, leading to blistering. The optimum oil level was determined through experimentation to avoid paint failure. It was also observed that a variance in the sheet surface roughness of ±0.4 µm did not appreciably affect paint failure.

Prevention of Micro-Flow Marks in Cathodic Electrodeposited Primer Coating in Automotive Industries

There was a defect of severe micro-flow mark lines in cathodic electrodeposited (CED) primer coating on car components. This problem was highlighted after final painting. This article describes the tests performed to determine the root cause of the defect. Tests included a surface profile of the CED coating and the determination of the microstructure and nickel content of the phosphate coating beneath the CED coating. The investigation identified the optimum concentration of nickel in the coating to refine phosphate grain size and create a unity crystal aspect ratio. It also found that the triple point junction of phosphate crystals determines the porosity to provide a uniform CED coating surface finish.

Protective Coatings

Applying an organic or metallic barrier coating between a corrosive environment and the material to be protected is a fundamental method of corrosion control. In fact, coatings and linings represent the most widely used method of protecting most metals.