Problem: Measures to prevent condensation on a water pipeline exterior led to conditions adverse to application and curing of any ordinary epoxy primer. The Big Creek Pipeline courses through the western Sierra Nevada mountains, delivering water to two pump houses from Shaver and Huntington lakes. A recoat of eight miles of the pipeline exterior began in August 2023. Because the pipeline is a vital piece of California’s water supply program, owner Southern California Edison needed to keep it operating during the project. Summer days in the Sierras are hot. Water flowing through the pipeline is cool. The contractor eliminated condensation by erecting climate-controlled containment tents along pipeline sections. Chillers pumped cold air into the tents to keep the pipeline surface between 49 and 50 degrees F. That’s too cool for ordinary epoxy primers to cure.
Solution: The Carboline coating system ultimately chosen for the project included Carboguard 890 LT, a versatile epoxy mastic containing catalyzing additives that support curing down to 40 degrees F. The topcoat, Carbothane 133 VOC, cures down to 35 degrees F. It also boasts excellent abrasion resistance, an important defense against wind-driven sand during the dry season.
Result: Application of the coating system has progressed without issue. The coating cures as intended despite the cold conditions. Painting paused for winter last November and resumes this spring. 800-848-4645; www.carboline.com
