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Pittsburg Tank and Ecodur 201M Manual Tank Coating

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An overflow steam tank at a hardwood flooring plant in Warren, Arkansas, was failing due to corrosion that had eaten away to the point where holes were causing leaks onto the plant floor.
 
The leakage was rapidly getting to the point where there was an urgent need to shut it down and carry out remediation. There was even the further threat to production that the tank might have to be replaced if no solution was found.
 

Problem
It was apparent from inspections carried out that, at the very least, any effort to use conventional epoxy coatings would have necessitated the entire operation being closed down because of VOCs and the extensive cure times required by conventional coatings. Also, the location of the tank meant that prep work would also have been highly complicated and lengthy as the tank was surrounded by inlet and outlet piping.
 
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Conventional epoxies require an even higher level of prep work than Ecodur needs. Normal Ecodur prep is a 1 to 1.5 mil profile surface prep as standard. This was a significantly corroded tank, which would normally have had the rusted metal taken down to a near bare metal state. Conventional sandblasting was ruled out because of the highly confined conditions, so manual prepping with heavy wire brushes was used. All loose scale was removed.
 
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Solution
This was, in the final analysis, a case where conventional epoxy coating remediation was not a practical option. The unique qualities of Ecodur was the only viable solution due to its exceptional stick, no VOCs, faster set up times, and ability to bridge all but the largest corrosion holes without matting or welding reinforcement. Ecodur 201M (manual product) was applied far more thickly than standard to form a thick, inert and permanent layer of what is essentially a plasticized gypsum. Because it retains a measure of flexibility and is highly chemical resistant, the thick bond was also applied 11 inches up the interior of the tank to provide additional integrity.
 
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Application Results
After the first coating, a puddle of Ecodur was found on the floor below the tank. Some corrosion holes, enlarged during prep work as scale was removed, proved too large. A steel plate was welded on the outside of the tank over the leaking area. Later inspection showed that the welding operation had not affected the coating on the inside.
 
The Pittsburgh Tank crew was able to go back into the tank immediately after the weld job and re-apply a coat over the general weld patch area with a 100% bond to the original coat. Epoxies have a 10-hour or less window for doing such work whereas with Ecodur there is, for all practical purposes, no time limit.
 
Ambient temperatures were in the region of 90F and so the total absence of VOCs or any solvents, made the working conditions far more tolerable than they would otherwise have been with conventional epoxies.
 
For more information on how our coating products can help you, please contact Pittsburg Tank & Tower Group (below) or us at: info@castagra.com

Contractor: Pittsburg Tank & Tower Group
Patrick Heltsley pheltsley@watertank.com
Don Johnston djohnston@watertank.com