Metal Roof Repairs
Certain industrial facilities like steel, chemical, and ice plants must stay safe, operates effectively without any malfunction, and no unintended maintenance requirement or replacement for decades. In order to safeguard the equipment from untimely deterioration, standard three separate coating are used, usually in epoxy, zinc or urethanes. Although this metal roof recoating system is commonly used, it’s not always the best choice.
With regards to safety, urethane topcoats are not that great since they have glossy walking surfaces that attribute to slip and fall risks, specifically if the walking surfaces are moist, humid or wet. Also, the usual exterior roof coating like that of epoxy and urethane can release harmful VOCs, HAPs, as well as odors while being applied, and can possibly contain flash points that call for further distance or proper care once used around hot or flammable processes.
Precaution is not the only concern when using traditional roof coatings but also time since their application can also hamper production for days as they generally need extensive metal surface preparation, a prime coat and two topcoats with no less than eight hours of drying time – also referred to as ‘minimum recoat time’ – between each coat. In addition, unfavorable weather or environmental conditions can further hold up the production, and may even demand re-blasting of the surface when an environmental delay go beyond the coating’s maximum recoat time.
According to Mobley Industrial Services (a multi-service specialty contractor serving the chemical, petrochemical, and refining industries) project manager Jay Harris, “Traditional coatings in some cases have significant drawbacks. They need extensive surface prep and must meet specific conditions, including minimum and maximum recoat times before they can be applied. Due to this, it can take a few days or longer to apply three coats, depending on the size of the job and environmental conditions. To avoid overspray issues, hand rolled application is often required.”
In search of a much better solution at a petrochemical facility on the Gulf Coast, Harris recently utilized a newly developed roof recoating product called the ‘EonCoat’ by a Wilson, N.C.-based company with similar name, that will help improve the workplace safety and bring back roughly 35,000 sq. ft. floating roof tank to service in approximately half the time needed by standard coatings.
This type of corrosion coating is included in the latest group of sturdy, Chemically Bonded Phosphate Ceramics (CBPCs) that can end corrosion problems and lengthen equipment life. Unlike the usual typical paint polymer roof coatings which sit on top of the substrate, the anti-corrosion coating attaches through a chemical reaction with the substrate, and minor surface oxidation will in fact enhance the reaction. Due to this, corrosion promoters like oxygen and humidity will not be able to go through behind the coating, like they normally do with regular paints. This corrosion barrier is covered by a genuine ceramic shell which defies corrosion, fire, water, abrasion, chemicals, and temperatures of up to 1,000 degrees F.
Ceramic coatings like this sort comes with two, safe ingredients that don’t interact until applied by a plural component spray gun such as those normally utilized when applying polyurethane foam or polyurea coatings. Due to the ingredients not blended, and that they do not come together before application, the need for harmful VOC-generating component is avoided, same goes for HAPs and hazardous odor. This safe characteristic of ceramic roof coatings means that working on them can be done even in populated/occupied locations.
The concern for possible accidents is also lessened when choosing ceramic roof recoating as Harris explained that “Unlike a slick urethane surface, the hard ceramic surface provides better footing and minimizes the risk of slip and fall hazard, particularly on wet, moist, or humid surfaces.” He also added that, “With no VOCs, HAPs, odors, or flash point, it’s also safer for the applicator and work environment.”
Compared to the customary roofing recoating systems that calls for three coats, a mere single application and small prep for the protective ceramic coating are already enough; hence giving facility maintenance managers with noteworthy, upfront savings. If the substrate is made of steel, sandblasting until there is a bright metal surface for the coating to stick is no longer needed because using a brush blast is already enough to efficiently remove loose rust. After the application of the ceramic coating, it can quickly get dry in just a matter of minutes, safe enough to be walked on in only 15 minutes and the roof back on its function in roughly an hour.
Although the Mobley Industrial initially made an estimate of more than 20 shifts to blast and coat the floating tank roof with a customary three-coat roof recoating system, the entire project was fully completed in just ten shifts with the use of the ceramic coating. Harris explained that this happened because “With EonCoat surface prep was minimal, and there was no need for a primer or multiple topcoats because one coat did the job.” He then added that “Unlike traditional coatings, there were no minimum or maximum recoat times, and we were able to spray the ceramic coating instead of hand roll it. Since it dry falls within ten feet, there was no concern of overspray. This expedited the application process with much less labor.”
When it comes to the comparison of ceramic roof coating versus the standard coatings for petrochemical plants, Mobley Industrial Services Quality Control Manager, Wesley Newburn addressed some of the great benefits that can make the application and quality assurance process more efficient. Newburn said that “For traditional coating application, the first step is to remove soluble salts to a permissible level, which includes site checks for chlorides, nitrates and sulfates.” He then further explained that, “If they are above the maximum levels allowed by the refinery, they must be removed by chloride and pressure washing. This normally will take at least one 10 hour shift. With the ceramic coating there is no need for soluble salts to be removed, which is an advantage over any other coating in the industry.”
Using the customary roofing recoating system, extensive surface preparation will be necessary and it’s often done gradually to avoid chances of surface oxidation, which will then demand re-blasting. As Newburn puts it, “Typically you need to keep an SP-10 throughout the entire blast operation, cleaning operation, and painting operation with traditional coatings. You may need to rent D-H equipment because humidity above 60 percent will oxidize the surface and require re-blasting.”
The Mobley Industrial Services manager then shared, “Perhaps the biggest advantage with EonCoat is that there’s no worry about surface prep. Newburn explained why, saying that “You can blast the entire surface, then coat it without concern over losing an acceptable blast. There’s no need for D-H equipment because the ceramic coating can be applied when it’s wet, humid, or even raining. A little surface oxidation makes it adhere better.
Newburn believes hydrocarbons are the main root of roof coating delamination at petrochemical facilities. To avoid possible delamination at refineries with customary coatings, every hydrocarbon like oil and grease should be detected by black light methods, then successfully eradicated by chloriding until black light passes. This hydrocarbon removal process is not needed when using ceramic coating since it will not stick on hydrocarbons; therefore the coating will ‘bubble” once applied on dirty surfaces or on the poorly prepared substrate.
It’s not difficult to detect a weak substrate or messy roof surface because as Newburn explained it, “You can immediately identify and correct poor surface prep during application.” He also suggested that “For quality assurance, you can also take the coating’s dry film thickness as early as 15 minutes after application at 75 degree F. That means the coating can be performed and corrected at the same time, which makes work quicker and gives a more predictable outcome.”
Lastly, Harris of Mobley Industrial Services made a strong and valid conclusion that “For enhanced corrosion protection, production uptime, as well as workplace and environmental safety, any industrial user who uses traditional coatings should consider EonCoat.” That said, it’s would be great to choose a roof recoating system that is not only of high quality but also safe and will offer upfront savings.