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Bringing New Life To Old Dams – Ecodur Shown To Be Effective Overcoat For Coal Tar Enamel

Photo by Dantripphoto

Photo by Dantripphoto

Reno, Nevada – One of the oldest protective coatings known to Man, coal tar has met its match in the form of a completely non-toxic veggie-plastic coating Ecodur that can overcoat it and give it decades more life in critical installations in the U.S. such as hydro-electric, waste-water and drinking water facilities.

“Coal tar has been around for thousands of years as a coating material and it has proven its robustness, but its useful life is not indefinite and it ran afoul of the regulatory environment decades ago that recognises the potential threat its chemistry contains,” commented Castagra CEO, Peter Roosen.

Congress passed the Clean Air Act and the Clean Water Act in the 1970s, severely reducing the use of coal tar enamel and lead-based paints (CPSC 1977). In 1992, the EPA cracked down on manufacturers of high volatile organic compound (VOC) coatings.

Ecodur, a polyurethane based on castor oil and gypsum, has no VOCs, no BPA, and does not contain, use during application, or require solvent use in clean-up. Importantly, it is ANSI-NSF 61 rated for contact with potable water. It retains its flexibility for its lifetime and generally has twice the adhesion properties of conventional epoxies, and hence does not micro-crack especially on steel.

The U.S. Bureau of Reclamation, in a public report, states that in general use, epoxy coatings sometimes last 10–15 years, while others last 30 years. Reclamation has only been using the aromatic polyurethanes for 10 years, but has had only one premature failure (due to insufficient surface preparation). They hope polyurethanes will last 40+ -year service life.

The Bureau has a big problem with zebra and quagga mussel fouling water flow at many of its facilities which have original coal tar enamel (‘CTE’) which cannot be replaced with the same material.

The Bureau stated in a report: The coal tar enamel appears to be the weakest link for all of the systems present. In general, the presence of solvent in the overcoating material appears to have a detrimental effect on the integrity of the CTE which further weakens the system. It is desirable to be able to overcoat the coal tar enamel which is ubiquitous on existing Reclamation equipment with an effective foul release coating system to prevent the attachment of zebra and quagga mussels.

Roosen continued, “We tested Ecodur on very old test samples of coal tar enamel which was well over 20-years-old and, as we thought, the bond was phenomenal. We already knew how well it bonded to asphalt where a sample strip on a public road has held up for more than 20 years. Samples of Ecodur chips pickled in brine have shown no measurable degradation after over 20 years.

“Ecodur has also been successfully tested on creosote-soaked railway ties so this is additional evidence of how well it works protecting tar-based coated objects whether they be wood, concrete or steel.”

“We know anti-fouling paint can be applied over Ecodur, so we have a two-step solution to the mussel problem rather than a one-step. But what Ecodur will bring to the table is giving the original CTE coating a radically extended service life.”

Roosen concluded, “Corrosion costs the U.S. over a trillion dollars a year. In 2002, one respected study placed its annual cost at $276 billion, so this probably reflects a marked deterioration in the nation’s infrastructure. Certainly, most, if not all motorists will have observed the poor state of many concrete bridges for example.”

Castagra Products Inc., which has its headquarters in Reno, Nevada, has its main toll production facility in Houston in Texas. It is focussed on providing ultra-protective non-toxic coatings for flooring, roofing, water and waste water industries, oil, gas, frac production water storage tanks and pipes.