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THE CHALLENGE: An oil-fired power station located ion the Sea of Cortez in Mexico receives fuel oil from tankers discharging in deep water at the end of a 1.2 Km long steel and concrete pier. The pier is a concrete cap sitting on clusters of steel pilings from 30-36 diameter. The coating applied to these pilings was in very poor condition and was compromising the effectiveness of the impressed current cathodic protection system, (ICCP). An effective replacement coating was required which had to be installed in underwater or wet splash conditions.
THE SOLUTION: BIO-DURŪ 561 was selected as the replacement coating primarily because of its ease of application underwater. On large projects the old-fashioned Splash-Zone type coatings are far too difficult and slow to mix and apply. Splash-Zone application by the tedious patty-cake press-into-place method is useful for only limited repairs whereas BIO-DURŪ561 is designed for a smoothing-on application similar to spreading peanut butter on toast. The Mexican contractor used application tools fashioned from discarded conveyor belting and reported applications rates many times faster than the Splash-Zone thus maximizing diver productivity in the water.
Although BIO-DURŪ 561 is a little more expensive per gallon it worked out to be considerably less expensive than Splash Zone per square foot because only about 40 mils, (1,000 microns), are applied versus over 1/8 of 125 mils/ 3,175 microns. Added to this the substantially lower cost of application resulted in significant saving to the contractor. The divers and other workers had no previous experience working with BIO-DURŪ 561. Because of its built-in ease of use characteristics they were immediately able to mix and apply the product with excellent results.
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Surface preparation was by hand-held pistols using 4,000-psi seawater with entrained beach-sand delivered through the venture system. This very simple and inexpensive equipment was perfectly adequate in the shallow working depths of this project.
The degree of blasting obtained was generally White Metal with islands of tightly adherent old coating. The BIO-DURŪ 561 applied easily over the abraded old coating as it did over bare steel. Since the BIO-DURŪ 561 contains no solvents it cannot weaken or soften old coating residues even remnants of old antifouling coatings.
Freshly applied BIO-DURŪ 561 was not disturbed in the wave action area by even 2-3 waves washing against the fresh coating. Experience has shown that only sustained strong current is able to move the uncured material. Once cured the coating is extremely tough, thanks in part to its reinforcement of Kevlar microfibers.
RESULT: The project was completed on time and under budget. Three years after completion it was inspected by a team of engineers from the Mexican Electricity Commission in Mexico City who reported ZERO percent deficiencies in the project quite a testimony to both the contractor who performed the work and the effectiveness of BIO-DURŪ 561.
For more information contact:
Jeff Longmore, Technical Director
Thin Film Technology, Inc.
P.O. Box 580669
Houston TX 77258-0669
Phone: (713) 910-6200
Fax: (713) 910-6210
Email: jeff@thinfilmtech.net
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