PAINTSQUARE BLOG

When a Sag Is Not a Sag

There’s a concept in martial arts that the first time a student sees a punch, it is just a punch. But then, as the student begins to learn the nuances of the punch—say, a right cross—the punch becomes a complex, intimidating almost unfathomable thing.  And the beginner’s punch is really no punch at all.

To deliver a right cross properly, the student must learn to keep the heel of the back foot off the ground and pivot on the toes, like squishing a bug or putting out a cigarette, to engage the hips. 

The pupil must learn to twist the body and not lean, for to lean is to lose one’s balance and present it as a gift to your opponent. The student needs to learn to raise the right shoulder to protect the right side of the chin from a hook. The student must learn to keep the left hand up, relax until impact, breath at the right moment, and on and on and on.

Then, after many years of training, the punch is once again just a punch.

Client 1 – The Sag

We had been working on the lining of the interior of a 60-by-40-foot-tall open-top floating roof tank. Our scope was:

• Identification of an optimal corrosion mitigation system;
• Development of site-specific, asset-specific specifications;
• Inspection; and
• Ongoing consulting as required.

The coating system we specified was a 100-percent solids epoxy requiring plural component equipment to spray at 40-60 mils dry film thickness (DFT). Surface prep was SSPC-5, NACE 1.

The contractor, while competent, was not accustomed to spraying with a plural component system, so, to supplement their efforts, we arranged to have a separate technician onsite for startup.

As with most coating projects, it seems, there were issues with temperature (dancing around the critical 55°F mark), equipment, logistics and in-line heaters. So when they first started spraying, before they were able to get a good spray fan, the material was applied too thick, and it ran.

Warren Brand

Sags from spraying plural component material before a good fan spray had been established.

The resulting sags, like the right cross, was something I was intimately familiar with. I have personally sprayed thousands of gallons of these types of materials and knew, from experience, that they were of no technical consequence and long as:

• The run and areas immediately surrounding it were holiday-free;
• It was a 100-percent solids material (no risk of solvent entrapment);
• The area just above the sag was at the minimal DFT identified in the specificaiton;
• It was not an area where the floating roof would travel; and
• The coating had properly cured.

I knew—and received confirmation in writing from the material supplier—that the sag would have no impact on the performance or durability of the coating system, despite the fact that it was clearly beyond a 40-mil DFT.

We certainly could have recommended that the contractor remove the sags, but we were on a very tight schedule and were trying to move the project along.

Looking back now, being that hindsight is 20/20, this was akin to one of my martial arts students asking why they couldn’t lean into a punch. Except I, being overly self-confident, didn’t even think to ask any other questions. 

I failed to see the sag for what it really was—and what it really meant in this specific case.

Warren Brand

Author’s own saggy handiwork from about 15 years ago; area being spark-tested. In this case, we intentionally over-sprayed the coating system due to the severely pitted and corroded substrate. This tank remains in service and the coating pristine.

The sag, and there were a handful of others, was on the far side of the open-top floating roof tank a few feet from the top. It was at the exact opposite side of where the winding hot-dip galvanized (HDG) coated walkway wound around the tank and ended in a platform overlooking the sags. It was, in essence, the first thing that caught your eye as you climbed up the last few steps and onto the landing.

They could not have been more conspicuous.

I was recently called out to a meeting on a Monday (Nov. 9), where the owner asked about the sags. I explained the technical issues surrounding them, and he took me aside and said: “We’ve just spent over a million dollars on this project. This is an area where reliability engineers and operators will come and look at this tank for decades.” (We designed the coating system to last well in excess of 15 years.)

“Every time a new engineer looks at this tank, I’m going to get a phone call or email asking if the paint is peeling or damaged,” he continued. “When the plant manager or anyone else looks at this, they’re going to wonder what kind of paint job this was and who did it.”

I felt sheepish and ashamed. How did I not think of this on my own? I’ll tell you: because I was overconfident. I was like the student throwing a first punch while thinking he knew what a punch was.

But I could not have been more wrong. In a world where perception is reality, I had dropped the ball. I had leaned into my right cross, lost my balance and faltered.

© iStock.com / Viktor_Gladkov

In a world where perception is reality, I had dropped the ball. I had leaned into my right cross, lost my balance and faltered.

I had been so focused on what I knew, that I didn’t even consider what I didn’t.

When I first started my consultancy a few years ago, I had some very specific ideas of how to do things. In fact, quoting from my own literature: “Each project is a completely new undertaking, and must be addressed as such.”

Client 2 – The Complexity of the Distressed Floor

In contrast, another project we started recently had to do with a distressed floor.

For those of us who have worked on failure analysis of these types, I can think of nothing more complicated.

Concrete, by its nature, is a complex amalgam of stuff that can vary from pour to pour and, on occasion, within a single pour. Moisture content, humidity, temperature, admixtures, air entrainment and myriad other concerns come into play in evaluating a coating failure—and that’s even before you start to look at the coating system itself.

I’m not a petrographer or chemist, but I was required to pour through hundreds of pages of documents, photos, conflicting technical reports, petrographic analysis and references to a wide range of standards, including ASTM 5084, ASTM F-1869, ASTM F2170 and many more.

While this was not new to me, it was far more complex than the sag, so I studied everything much more closely. I asked many more questions. I lived up to the promise in my literature that “Each project is a completely new undertaking, and must be addressed as such.”

By Polyparadigm / Public domain via Wikimedia Commons

Concrete, by its nature, is a complex amalgam of stuff that can vary from pour to pour and, on occasion, within a single pour.

And, because I was looking at this project from a new perspective and not being complacent or overconfident in my thinking, I will be—and am currently—better able to provide solutions.

I work with coating professionals, owners, technicians, inspectors, sales reps and others in our industry on a daily basis. I find, as with seasoned martial arts instructors, that the most competent are those who give their opinions, yet are open to alternative views. They are patient with questions and generous with their time. 

The sag on the interior of the tank will haunt me for the next 15 years. It will be a reminder of the dangers of hubris—and will motivate me to do better. And isn’t that all we can do with any endeavor? To try to do better?

ABOUT THE THE BLOGGER Warren Brand Warren Brand’s coatings career has ranged from entry-level field painting to the presidency of two successful companies. Over nearly three decades, he has project-managed thousands of coating installations and developed specs for thousands of paint and coating applications. NACE Level 3 and SSPC PCS certified, Brand, an MBA and martial-arts instructor, now heads Chicago Corrosion Group, a leading coatings consultancy. Contact Warren. SEE ALL CONTENT FROM THIS CONTRIBUTOR