When crews at Lakeside Painting Inc. head for an industrial plant to do tough paint-preparation cleaning, they go armed with bags of sponge pellets. Sounds like a joke waiting for a punch line, right?

Even Joe Pangburn, the president and owner of the company based in East Troy in southeastern Wisconsin, admits he was a bit doubtful at first when he heard about this unusual cleaning system made by Sponge-Jet Inc. But he was totally sold once he saw the system make short work of a particularly grimy cleaning project inside a Milwaukee factory.

“Sure, I was skeptical,” admits Pangburn, who bought his first Sponge-Jet machine four or five years ago. He now owns two 85 L Feed Unit blast pots and one ME/MR 30 separator/recycling unit. “I thought it would be more expensive than other media systems, too.

“But I was also very intrigued,” he adds. “Sponge-Jet came in and did a demo at the plant and it worked exactly like the company officials said it would.”

Here’s how it works: A Sponge-Jet blasting pot, powered by an independent air compressor (up to 300 cfm at 100 psi), blasts a dirty surface with a stream of the tiny synthetic sponge pellets impregnated with abrasive bits of aluminum oxide grit. Upon impact, the pellets flatten and expose the abrasive. When they rebound off the surface, the pellets expand and create a vacuum that traps what would otherwise become airborne particles.

Before Pangburn heard about Sponge-Jet, he used power washers when possible, as well as dry ice, corncob, sand and walnut shell pellets. His company primarily cleans factory and plant ceilings, as well as the structural supports that hold them, before repainting them.

“Most of these ceilings are very dirty from the processes used, like heat-treating, or from cutting fluids in machine shops, as well as from normal dust and dirt,” he explains. “If these surfaces are even a little bit oily, that impedes paint from adhering, so we have to get it off.

“Often enough, we can’t use water because it gets into everything from outlets and electric motors to bus bars,” he continues. “And plants can’t afford to completely shut down just because a small portion of a facility needs to be painted.”

Moreover, water filled with contaminants must be collected and properly disposed of, which can be expensive and time-consuming. Other dry media clean effectively, but create large amounts of dust, which is potentially explosive, not to mention that it gets inside everything. The sponge pellets reduce the amount of dust and boost safety for both Lakeside crews and employees working at the facility they’re cleaning, Pangburn notes.

In addition, other types of cleaning media typically can’t be reused. And if the paint is lead-based, the media and paint chips and other debris must be disposed of properly, and contractors typically pay by the pound to do so. That gets expensive, Pangburn says.

Sponge pellets, on the other hand, can be recycled over and over; a recycler unit made by Sponge-Jet utilizes a motor that vibrates a series of screens, with progressively smaller openings to separate large pieces of debris, sponge pellets, and dust and other fine materials. It also cleans the sponge pellets.

Job requirements determine how many times the pellets can be recycled. If an operator uses very abrasive, heavier-grit pellets, a skilled operator might be able to reuse pellets three or four times; if they use less-abrasive, finer-grit pellets, then an operator might get seven or eight recycles, he says.

“The heavier grits break down faster,” he explains. “Blasting at the correct air pressure combined with the proper feed rate is critical to minimizing media breakdown.”

Eventually, the sponge pellets break down and require disposal. But Pangburn points out that his crews will use dramatically less media than with other methods – an average of five to eight times less debris than sand-blasting, he estimates. Plus, the media is much lighter, which pays dividends when it comes to disposal fees.

Sponge-Jet makes almost two dozen different kinds of sponge-media abrasives designed to clean a variety of surfaces. On one end of the cleaning spectrum, Pangburn says his crews once used sponges impregnated with minuscule plastic beads to remove a powder-coated finish that was mistakenly applied to a machine in a chocolate-making plant. “They wanted the coating off the machine but didn’t want the metal below it profiled, or abraded,” Pangburn explains. “It worked perfectly … blasted off the powder coating but left the steel very smooth.”

Thanks to the Sponge-Jet units, Pangburn says he now takes on jobs he had to refuse years ago.

“These machines absolutely have helped us expand our customer base,” he says. “We have a solution to a problem for which very few other guys have a solution … the units allow us to clean surfaces that can otherwise be very problematic. Without them, we might be subbing out the blasting to someone else – or just turning away work. And nobody wants to do that.”