Protecting your assets from corrosion
PROTECT YOUR ASSETS FROM CORROSION
By Alexandra I. Wolf
When a new bridge is being fabricated or an old bridge is being rehabilitated, a critical decision must be made regarding what type of coating should be used to protect the asset from corrosion. There are many factors to consider when determining whether to use paint or to metalize, among these critical factors, a paramount issue to consider is cost.
Traditionally, paint coatings have been employed more frequently than metalizing, but more and more Departments of Transportation, the Federal Highway Administration, numerous city transit authorities, and maintenance engineers are turning to metalizing. While metalizing does have a slightly higher initial price, all of the studies that have been conducted by the FHWA and other government and private agencies, have determined that the life cycle cost savings of metalizing far exceed what would be spent on the initial painting and the continued maintenance required by paint coatings.
Many case histories exist in the United States that demonstrate how metalizing is more durable, dependable and resistant to corrosion than paint coatings, regardless of the environmental conditions. As one travels over various bridges throughout the United Sates, one can see that most are undergoing one of the many stages required for the maintenance of paint coatings. The majority of these structures are developing patches of rust, huge paint blisters, and brown trails bleeding over the steel, concrete, and ground. Some of the bridges have resorted to the “spot paint method” on the existing coatings to cut costs. In reality, by the time they finish those spots, new ones will have developed which will require going back to start the same process over again. The costs involved using this method are astronomical when added up over the years. Some of the bridges even look as though they’ve had camouflage applied to the beams. This camouflage effect occurs when the old paint color cannot be matched due to batch variations, UV effects on old coatings, and the use of different brands of paint for reasons such as the EPA’s VOC regulations. A better choice would be to employ metalizing for the spot coating method. By doing so, the entire structure could eventually be protected from further corrosion by a method that is proven to last for decades.
The paint industry does not like this solution and will continue to fight and bad-mouth the metalizing industry. The one draw back that they usually point out is that zinc has only one color. That argument is correct. Zinc metalizing provides a beautiful shimmering silver/gray color, which is far more appealing than the brown trails of rust, the pealing and blisters caused by failing paint. A color top coat can be applied to metalized surfaces for aesthetic purposes, but it is not necessary for corrosion protection of the structure.
The metalizing process uses 99.9% pure zinc or 85/15 zinc/aluminum alloy, and other alloys if requested, compressed air, and electricity. There are no VOCs generated, no storage or shelf life issues, and no hazardous wastes, so in turn helping preserve the environment. Our alloys are not effected by UV rays, they are abrasion resistant, and best of all, our metalizing process has been tested and proven to be just as fast and FASTER than airless paint systems with no porosity. Remember, once a structure is metalized, you won’t see us for 50 to 100 years!
Certificates for zinc and aluminum applications, lab studies, and client references are available upon request