The Cost of Corrosion

From looking at your website, Polyguard Products appears to be heavily focused on corrosion.
JM. We certainly are. The cost of corrosion to the US alone is estimated at one to five percent of GNP. Additionally, people sometimes forget that corrosion often causes serious environmental problems, such as spills. Within the set of corrosion opportunities, Polyguard has developed a number of products that address unsolved corrosion problems.

Can you explain the main unsolved corrosion problems facing the industry today?
JM. A major problem is corrosion on buried oil and gas transmission pipelines. Cathodic protection systems (CP systems) have been developed to act as backup protection to the pipeline corrosion coating system; if the corrosion coating, which is the primary protection, fails, the CP system delivers electrical current to the steel pipeline surface, which can effectively stop the corrosion process.

CP systems have been accepted worldwide. However there are many pipeline operators whose cathodic protection systems are being rendered ineffective, because they have installed corrosion coatings with a solid plastic film backing on the pipeline. Solid plastic film backings have the property of high electrical resistivity, which means that solid plastic film backings block the passage of protective electrical current from the CP system to the steel pipeline surface.

The phenomenon which takes place when protective CP currents are blocked by the backings of corrosion coatings is called cathodic shielding. Dozens of technical papers have been published on cathodic shielding since the mid 1980s, so it is surprising to see that, by some estimates, as many as half of the pipelines worldwide, continue to use corrosion coatings with solid plastic film backings. Cathodic shielding is a problem for the pipeline operators, and an opportunity for Polyguard, since we have developed corrosion coatings that do not block the protective CP current.

And there other unsolved problems?
JM. A second unsolved problem is hidden corrosion, examples of which are corrosion under insulation and corrosion inside flanges. Polyguard has a heavily patented gel product which, when applied to steel surfaces, reacts with elements in the steel to form an extremely thin glasslike mineral layer. This gel product is under test on the Alaskan pipeline, and is rapidly becoming standard in the food and beverage processing industry, where corrosion under insulation has been a huge problem.

Finally, a third unsolved corrosion problem is crevice corrosion. This is corrosion in tiny gaps, which are not subject to flushing by whatever fluid rinses off the major portion of the surface area. Because contaminants can become concentrated in crevices, crevices can develop a whole different chemistry from the rest of the surface. A good example of crevice corrosion is inside steel cables or wire ropes. Polyguard has modified gels that solve crevice corrosion problems.

How long have the modified gels been around for?
JM. Early versions were formulated for the US Navy. In the 1990s the Navy identified several corrosion problems that they deemed 'mission critical'. One of Polyguard's gel formulations, using a customized locking mechanism, solved the Navy's door locking mechanism corrosion problem. A second formulation solved the problem of corrosion of exterior steel elevator cables. These gels have been used by the Navy for the past 10 years for these mission critical problems, as well as some other corrosion problems.