A protective coating is only as good as the surface to which it was applied. To ensure the successful application of protective coatings on vessels, the use of marine temporary climate solutions are vital. Failure to control the environment could result in improper adhesion, premature failures and corrosion. By understanding why environmental controls are important when applying protective coatings on vessels, you’ll improve the quality and efficiency of this vital maintenance task.
How Climate Control Improves Surface Preparation and Coatings on Vessels
Marine vessels are complex metal structures that require ongoing maintenance and repair. Because of temperature variations and high humidity levels in shipyards, temporary climate control solutions facilitate creating the ideal conditions for surface coating projects and eliminate risks, such as adverse weather, corrosion and delays. The equipment used for marine temporary climate solutions include indirect-fired heaters, cooling equipment, ventilation systems and desiccant dehumidifiers to give you a completely controlled environment that optimizes the performance of paint systems.
Elements that are important to monitor and control include:
- Air temperatures: Air temperatures affect the rate in which surface coatings dry and cure. When temperatures are too warm, an application might dry too quickly and crack. Cool temperatures could prolong drying times, leading to project delays and improper adhesions. In general, manufacturers recommend that air temperatures remain between 56°F and 99°F.
- Surface temperatures: Having the ideal air temperature will not guarantee a coating’s performance. Surface temperatures are an equally important consideration because substrates absorb heat during the day and radiate it at night. The temperature changes promote the formation of condensation, which can cause pinholing, blistering and cratering. The ideal surface temperature for a marine vessel depends on the dew point temperature and manufacturer’s recommendations, which are usually between 40°F and 100°F. To prevent the formation of condensation, a vessel’s surface temperature should be at least 5°F warmer than the dew point temperature throughout the surface preparation and coating process.
- Dew point temperature: Dew point temperature refers to the temperature at which condensation forms on a surface. Shipyards tend to experience moisture problems on substrates when surface temperatures are close to or cooler than the dew point temperature, as condensation may corrode an exposed substrate and affect a coating application.
- Relative humidity: Moisture in the air lengthens drying and curing times, and negatively impacts the performance and durability of surface coatings. While each manufacture specifies the ideal humidity levels for their products, most recommend keeping humidity levels below 85 percent. When relative humidity levels are too high, the use of desiccant dehumidifiers along with heating and cooling systems will reduce more energy expenditures than the use of heaters alone. The power requirements of state-of-the-art dehumidifiers are similar to portable generators that skeleton crews use.
- Ventilation: Air circulation is vital to worker health and the prevention of solvent accumulation and entrapment, which cause coatings to fail. Temporary forced air ventilation systems ensure a space has adequate air circulation during a project.
- Wind: Wind is a common element in shipyards that aids with ventilation. High wind speeds, however, may accelerate the rate in which solvents evaporate as the coating cures. The ideal wind speeds are 15 miles per hour or slower. If wind speeds are too high, enclosing an area and implementing a forced air ventilation system will create an appropriate temporary environment.
When you use Polygon’s custom marine temporary climate solutions, a variety of instruments will monitor on-site conditions. You will have access to remote monitoring devices that record environmental conditions and send you alerts when they exceed parameters.
The conditions in which you apply a protective coating to a surface are just as important as its cleaning and preparation. Contact Polygon today and let us know what we can do to make surface preparation and coatings simpler and more reliable for your crew.
[U.S. Naval Forces Central Command/U.S. Fifth Fleet via CC License 2.0]