Rust in a cooling tower basin often begins quietly. A brown stain appears near a seam, around a fastener, or beneath an area where an older coating has lifted. Months later, the affected patch may be larger and the basin may begin losing treated water.
Recoating can protect a suitable basin and extend its useful service. It cannot restore metal that has already become dangerously thin or repair a structural failure. The condition beneath the rust must be understood before a coating is selected.
Determine How Far the Corrosion Has Progressed
Light surface corrosion is different from deep pitting, perforation, or failure around a seam. Inspect the basin floor, corners, welds, penetrations, supports, and areas around the makeup water connection.
Blistering or peeling coating may conceal corrosion beneath it. Active leaks, distorted panels, soft metal, or extensive section loss call for professional evaluation and repair before coating work begins.
A coating should not be used to hide a failing component. Damaged metal may require patching, welding, or replacement according to the tower design and the extent of deterioration.
Find Out Why the Coating Failed
Age is one possibility, but it is not the only one. Abrasion, poor surface preparation, standing debris, chemical exposure, and unsuitable water chemistry can all contribute to coating failure.
If the underlying cause remains, a fresh coating may fail in the same location. Review water treatment records and look for recurring deposits, biological growth, or chemical feed problems. The treatment provider should evaluate chemistry concerns rather than leaving maintenance personnel to guess.
Galvanized surfaces require particular attention because improper water chemistry can damage the protective zinc layer.
Surface Preparation Is the Real Beginning
Applying coating over loose rust, scale, slime, or damp material creates a weak bond. The basin must be taken out of service, drained, cleaned, and prepared according to the coating manufacturer’s directions.
Old material that is no longer firmly attached must be removed. Edges around the remaining coating should be sound, and cracks or open seams must receive the correct repair before the finish is applied.
Corners and irregular surfaces are easy to miss. Unfortunately, they are also common places for water to collect and corrosion to return.
Allow Enough Time for Application and Curing
A rushed repair during peak cooling demand can be expensive if the coating is exposed to water before it has cured. Temperature, humidity, surface condition, mixing, and curing time affect the finished result.
Plan the shutdown around the product instructions and the facility’s operating needs. Confirm that the selected coating is intended for cooling tower immersion service and is compatible with the prepared surface.
Order Tower Shield Coating From Universal Tower Parts
Universal Tower Parts supplies Tower Shield epoxy coating developed for cooling tower applications, along with sealants and many other replacement components. Product selection should be based on the basin material, existing condition, and intended exposure.
Call 602 997 0403 for product information or a free quote. Universal Tower Parts can ship cooling tower parts and supplies throughout North America and beyond.
Universal Tower Parts In Phoenix, AZ
Universal Tower Parts provides stainless steel and galvanized options, welded and gasketed, direct, gear reducer and belt drive units, with efficient Jedair fans, and Jedair low noise fans. Strainers, fan guards and louvers are well constructed, and designed to operate efficiently as they perform their function. Cool Core drift eliminators and fill are made by Universal Tower Parts expressly for our towers.
