Peeling blue coating forces questions at Lincoln Pool

peeling polyurea – Days after the Lincoln Memorial Reflecting Pool’s floor and walls were painted “American flag blue,” chunks of blue polyurea coating began floating off the interior—triggering viral footage, expert scrutiny, a reported vandalism probe, and uncertainty about wh

On the Lincoln Memorial Reflecting Pool, the makeover was supposed to look crisp, patriotic, and permanent. Instead. within days of the work being finished. photographs and videos showed cerulean chunks floating in the water—material that appeared to have detached from the pool’s walls and turned a routine renovation into an engineering mystery.

The renovation order came from President Donald Trump in April. As part of that plan, the pool’s floor and walls were painted blue. The coating catching attention online is polyurea: a fast-curing, durable surface membrane that can seal in water and is often used to coat swimming pools.

But while the videos spread fast, pinning down the cause has not. Engineering and pool experts describe a failure that may not have a single villain.

Tim Auerhahn. chairman of the Aquatic Council. said the blue coating likely has no direct relation to the large algal blooms also plaguing the monument. He also said the floating material is not simply a reaction to the hydrogen peroxide the National Park Service dumped into the water in an apparent effort to kill the algae. though he added that it “likely didn’t help. either.”.

David McFayden, CEO of paint and coating inspection company KTA-Tator, urged caution about assigning blame before a full failure analysis. “The failure of the adhesion to the substrate of that product probably could have been caused by many factors,” he said.

Auerhahn agreed on that point—and said hydrogen peroxide could have contributed because workers dumped it from the edges of the pool while the coating situation was still unfolding. Even so, he said it’s probably not the only cause. “it could have contributed to the issue, but it’s probably not the only cause.”.

McFayden said hydrogen peroxide can be used as a paint stripper, but the pool water would likely dilute it to the point that it couldn’t cause the current level of damage. He described how adding it to water quickly reduces concentration and argued the delamination would likely be “multi-factorial.”

“It was immediately diluted when it’s being added to the water. and there’s just so many other factors that could contribute to delamination of a polyurea coating on a surface like this. ” McFayden said. “It was very much likely that this was multi-factorial. When investigating engineering failures, we’re rarely going to see one single cause. There was a lot of different stressors to that coating, and they probably all had some level of contribution.”.

Another question is what happened before polyurea ever went on the pool. Auerhahn said preparation of the pool’s walls and floor before painting “American flag blue” would have mattered—especially given the project’s reported timeline. The cost, originally estimated at less than $2 million, has since ballooned to almost $15 million.

“It’s actually a really specific process to add a coating like this to any basin,” Auerhahn said.

When applying polyurea coats. workers need to add a new coat within 24 hours—or less. depending on the specific product—of the previous layer. That tight window helps ensure the layers adhere to one another and form a solid mass that blocks water from seeping through. A short timeline around five weeks raises the possibility that the coating was not applied in a way that prevented later separation.

Stress during application could also have mattered. Auerhahn said the bottom of the pool may have been affected by the presence of heavy equipment and trucks, and at one point by the presidential motorcade driving through while the coating was being prepared and applied.

Then there is the basic compatibility issue: what polyurea was bonded to. Auerhahn said the decision to use polyurea in the first place requires investigation, because “The material that you’re adhering that polyurea coating to is questionable. They were adhering it to granite.”

The precise material mentioned—Rhino Linings’ Pipeliner 5000—can bond to “virtually all substrates. ” according to the company’s commercial data sheet. but granite is not specifically listed. Rhino Linings was not the contractor that applied the coating to the Reflecting Pool. and the company did not immediately respond to a request for comment.

“There’s a big question mark as to whether or not there was some compatibility there for the adhesion with granite,” Auerhahn said.

He also pointed to conditions that the coating would face in Washington, D.C., including ultraviolet exposure and hot summer temperatures.

For the actual renovation contractor, the company named is Atlantic Industrial Coatings (AIC). AIC did not immediately respond to a request for comment. But in a statement posted on its website, the company said it and the U.S. National Park Service have identified areas of the pool that need repairs.

“These areas are a very small part of the massive 7 acre project. and do not indicate a failure of the liner. ” AIC said. “These repairs can not be made until the pool is drained. As soon as its feasible for the Park. the pool will be drained and AIC will be back to make those needed repairs as part of the warranty.”.

While AIC spoke about repairs after draining, the Trump administration has not issued an official statement identifying what caused the peeling.

In parallel, law enforcement activity has followed. The article says at least five people have been arrested for alleged vandalism of the pool. On June 21. President Trump said in a social media post that the pool would likely need to be drained for repairs and claimed that unnamed vandals had put a “250 foot long gash” into the pool’s façade.

McFayden said the only way to determine exactly what happened is a full failure analysis. That would include examining the pool’s ph levels, checking whether mistakes were made in preparing the surface to be coated, and assessing whether an improper material was selected, among many other variables.

At this stage. he said. the number of possible failure pathways is so large that it’s not realistic to rule anything out. He summarized the challenge with a line of experience: “If you’ve met one coating failure. you’ve met one coating failure. ” he said. “They’re all very different. There’s probably a lot of water chemistry involved in this situation. I can’t say that we’ve ever been involved in anything exactly like this before. to be honest with you.”.

The unanswered question—what exactly caused the coating to detach and float—now sits between multiple suspects: chemical conditions in the water. the preparation process on granite. the narrow application timing. stresses during installation. and the possibility that vandalism damaged sections of the pool. For a monument covered in symbolism and watched in real time. the peeling coating has turned a visual upgrade into a problem that may take a drained pool and months of testing to solve.

Lincoln Memorial Reflecting Pool polyurea coating Atlantic Industrial Coatings hydrogen peroxide algal blooms vandalism arrests engineering failure analysis granite substrate water chemistry