Steel Coatings Articles

Tanks For Thanksgiving

Vendor Team

Contractor Services
256 Marginal Street
East Boston, MA 02128
(617) 569-5630

Surface Preparation
Clemco Industries Corp.
One Cable Car Drive
Washington, MO 63090
(636) 239-0300

Dresser Rand
Coppus fans
West8 Tower Suite 1000
10205 Westheimer Road
Houston, TX 77042
(713) 354-6100

Frost Fighter
100 - 1500 Notre Dame Ave
Winnipeg, Manitoba, Canada
R3E 0P9
(888) 792-0374

Spray equipment
88-11th Avenue NE
Minneapolis, MN 55413
(800) 647-4336

Honeywell Safety Products
Biosystems gas detectors
900 Douglas Pike
Smithfield, RI 02917
(800) 343-3411

Ingersoll Rand
Surface preparation
800-E Beaty Street
Davidson, NC 28036
(704) 655-4000

For most of us Thanksgiving is a day to be spent with family and friends laughing over food and football. For Paul Flanagan and his crew at AMEX Inc., the Thanksgiving weekend was spent in frigid weather in a race to reline the bottom of an ethanol fuel storage tank. “I missed dinner with the in-laws,” Flanagan says with a wicked chuckle, “but it was for a good cause.”

The refinery tank was located at a 25-acre (101,101.41m2) Massachusetts-based marine terminal that serves customers in New England, Eastern Canada, and Quebec with a range of finished energy products, including gasoline, diesel, home heating fuel, and jet fuel. The tank in question was used for ethanol fuel storage. Ethanol may be an interesting fuel alternative, but it also dissolves the oxide scale from pipes and tanks, causing corrosion, and leading to leaks.

The tank had been drained in preparation for a new delivery of ethanol and the owners took advantage of the situation to make any necessary repairs. “The walls of this tank were in OK shape,” says Flanagan. “It was the bottom that needed relining.” The specs called for the use of a 100% solids epoxy lining system from Tnemec. “The project was done over the Thanksgiving break, so the contractor was dealing with low temperatures in terms of the environment,” Tnemec coating consultant Larry Mitkus recalls. “But the temperatures didn’t impact the cure or workability of the products.”

What A Blast!

But the weather did impact the conditions. The tank itself was surrounded by a dyke. Before the project even began, rain had flooded the dyke, so from the beginning, accessing the tank was a challenge. “We had to hire a crane to put all of our equipment inside the tank,” recounts Flanagan. “We needed to work as close to the tank as possible because we had to keep everything heated.” The crew used two 500,000 btu Frost Fighter heaters on site—one for the tank itself and one to heat the coatings.

The weather also impacted the time-frame. The job was scheduled for two weeks, but with winter weather on the way, every second counted. Measuring ambient conditions and monitoring weather forecasts became second nature. But the AMEX crew was unfazed: they had a plan.

Since the job was in a confined space, they established a manwatch with radio communication and a confined safety permit. They ventilated the tank with Copus 20,000 cfm fans and each crew member wore air monitors from BioSystems. They also performed a job safety analysis (JSA) for the job every day—targeting different analyses for different tasks. “If we were blasting, then the JSA focused on blasting; if we were painting, then that was the focus,” Flanagan explains. “We take safety very seriously and the crew knows that they have to be safe.” They also wore full safety gear including respirators, goggles, blast suits when blasting,

and Tyvek suits when painting.

For the shot blast, the steel tank’s bottom and shell were prepared in accordance with SSPC-SP5/NACE No. 1 White Metal Blast Cleaning to remove existing coatings and provide a minimum angular anchor profile of 3 to 3.5 mils (76.2 microns to 88.9 microns). “We used Clemco 600 lb. mobile pots and Ingersoll Rand 425 cfm air compressors to prep the 4,000 square foot (371m2) bottom.”

Armed With Tank Armor

Next, the AMEX crew used Series 351 Tank Armor, a 100% solids flexible polysulfide/novolac epoxy polymer repair and base coat putty, for seams, rivets and the chime area at the floor-wall transition. Series 351 was applied at 40 mils (1016 microns) to ¼" (0.64cm) dry film thickness (DFT).

Once Series 351 had cured, the bottom and shell were coated with Series 350 Tank Armor, a tightly cross-linked high-build epoxy phenolic lining that offers excellent resistance to 100% etha¬nol over a wide range of temperatures. “Using plural component equipment, the lining was applied to the floor and around the interior of the 80' (24.38m) diameter shell to a height of 24" (60.96cm),” according to Mitkus. “The lining applied well and built to 30-plus mils (762 microns) DFT in a single coat.”

Flanagan explains the process: “We used a Graco Hydrocat 45:1 King pump and 100' (30.48m) of heated line with 25' (7.62m) of whip line to spray-apply the Tank Armor coating. As we sprayed, we checked wet film thickness with a mil gauge to ensure consistency. Since the coating needed no primer and no topcoat, it was a straightforward process. When we were finished, we used a Tinker & Rasor high voltage holiday detector to check for any voids.”

So just how long did the process take? Although they did miss Thanksgiving, Flanagan and his crew were in and out of the tank in nine days, turning the tank back to the refinery with five days to spare. “The entire project lasted less than two weeks,” Mitkus adds. “They were in and out of there pretty quickly, which was important for this project.”

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