Constant wind, tiny isopods, a busy site, and a compressed deadline – this tank project presented multiple challenges for the unfazed foam crew.
By Jen Kramer
The power company knew that their 12,600-square-foot, 40-foot-tall, 70-foot-diameter, 1,000,000-gallon, service water tank was in need of exterior insulation. Although it was not yet corroded, given the elements and the location, it was just a matter of time. This company prides itself on being proactive and a scheduled shut down was looming, so they decided to take advantage of the opportunity and protect the tank – with fiberglass.
A forward-thinking Production Coordinator; however, had used spray polyurethane foam before and realized that fiberglass wasn’t the answer in this situation. He knew that SPF could provide insulation in a more efficient and effective manner. Given that the insulation installation would have to be accomplished within a tight window – after all, a power company can only be off line for the briefest of timespans – the company was willing to consider options that would provide a fast return-to-service. So, the job went out for bid, including bids for SPF insulation.
“The Production Coordinator was able to convince the power company that the soft fiberglass blanket that they initially wanted to insulate the tank with would provide poor insulation and wouldn’t last long,” explains Ken Wells, owner of Elite Insulation & PolyPro LLC (Elite). “We heard about the opportunity through Lapolla Industries. I went and did a site visit, put in a bid, and ultimately won the job.”
The Best Laid Game Plan…
This was not Elite’s first tank, although it was their first tank of this size. But they approach every job in the same manner: “We always have a good game plan in place before we start any project,” Wells says. “You prepare for everything that you can think of – and for some things that you can’t.”
That attitude saved the day – more than once – on this project.
Knowing that the clock was ticking, Wells and his crew pulled up to the site, and immediately discovered that this project was going to be different.
“The tank itself sits on a cement foundation. But, on site there are of a series of subterranean caves that are home to tiny, protected isopods, which are basically small crabs. And because the crabs are protected, nothing could leak onto the ground that might seep into the caves,” explains Wells. “But the power company was extremely helpful and proactive. They provided us with kiddie pools to put under our vehicles and our equipment – anything that might leak.”
Crabs protected, the crew faced another issue – one that would plague them for the rest of the job – the wind.
“The site sees a sustained 15 to 20 mph wind every day,” says Wells. “Fighting that alone wore us out by the end of each day.”
The wind also was the major topic of conversation at the pre-job meeting, as well as at daily toolbox meetings because with the amount of trades on site, everyone had to be aware of spraying and be well clear of the tank.
“We used windscreens, built from several layers of door screen and 1×2 lumber, attached to both sides of the tank, as well as a hand-held screening when we were spraying the top of the tank,” Wells states. “When the wind was at our backs, the spraying went quicker; when we were spraying against the wind, it was rough.”
In fact, according to Wells’ calculations, the weather, especially the constant wind, which at times gusted so fiercely that the crew had to stop work, added days to the schedule. He details Mother Nature’s capriciousness, “Between the heavy dew in the mornings, which often caused late starts, and the constant wind, we had quite a bit of unexpected down time on this project.”
The Actual Spraying
The job itself was straightforward. While massive, the tank was fairly new and in good shape.
“The surface prep portion of the project was standard,” Wells says. “We used a powerwasher to remove any loose dirt from the painted steel surface. The entire tank was cleaned in one day. Then, we started spraying at the top of the tank.”
To access the top, and upper sides of the tank, the crew used a 60-foot boom lift.
A representative from the power company was on site to monitor the job – including the Personal Protective Equipment (PPE) that the crew wore. This gear included full-face respirators with cartridges by 3M, safety harnesses when working on the lift, hard hats, goggles for crew not wearing full-face respirators, and cut-resistant gloves.
“They even replaced our regular utility knives with knives that had auto-retractable blades,” states Wells. “They were very safety conscious and very helpful.”
The safety measures also extended to a tagging system that was employed when the Elite crew was spraying the tank.
“The company would rope off the area with caution tape and signs,” Wells explains. “Yellow meant that personnel could enter the area, but had to wear respirators. Red meant that there was no entry. They would use this when we were spraying – especially when we were working on top of the tank because they had cut off the toe kick railing in order to allow us to foam the top. The toe kick rail stops objects from rolling off of the top of the tank. So when we were working up there and the rail was off, the tag was definitely red.”
Innovative Project Calls For An Innovative Solution
Wells and crew were able to pull their rig right up and access their Graco GT2 pump, H-XP2 proportioner, Fusion AP gun, and 200 feet of hose. Using this equipment, the crew spray-applied one-and-one-half inches of Lapolla’s Foam-Lok™ 2800-4G closed-cell foam, beginning at the top of the tank.
“But the tank is so massive, that we had to UV-coat each day’s sprayed foam, before the UV rays could damage it. And we could not use the specified silicone topcoat until the entire tank had been foamed because the silicone is very slick and it could not get on the unsprayed tank,” Wells describes the potentially sticky (or rather, non-sticky) situation, caused by the sheer size of the tank.
“So,” he continues, “each day we would use Lapolla’s Thermoprime to cover the freshly sprayed foam. This would buy time and would also protect the foam from UV degradation. We applied a light coat and, because it is black and the spray polyurethane foam is white, we could always tell what had been protected and what still needed to be protected by day’s end.”
It was a fittingly innovative solution for a job that was already in and of itself an innovative specification.
Then, when the entire tank had been foamed, they sprayed six barrels of Lapolla’s low-solids silicone coating on top of the SPF. “We applied the coating in 30 mils DFT to the tank top and 20 mils DFT to the sides,” Wells explains.
And with that, the tank was protected – three weeks from the day they started – just within the deadline.
“It took two weeks to foam and one to coat. We used six sets of foam and six barrels of silicone,” Wells provides the final tally for the massive 1,000,000 gallon tank.
Any final lessons from the job, besides the fact that this project proves that spray polyurethane foam is a great insulator for giant tanks?
Perhaps Wells sums it up best when he says: “No matter how well you prepare, you will have issues, and we had some, but when you have good people backing you up; you can quickly get back up and work through it.”
For more information, contact www.polyprollc.net and www.lapolla.com.
Photos courtesy of Elite Insulation and PolyPro LLC •