Some consider it old-fashioned to perform full chip-outs. Decades ago, when the idea of refinishing pools started, chipping and removing the entire surface was only natural. But it’s grueling work, so when bond coats became available, many plasterers and renovators jumped at it.

However, this option doesn’t work for everyone. In some desert climates, professionals say the dry air can compromise bonding solutions. And for older pool markets, applying a bond coat doesn’t make sense if the vessel already has more than one layer of finish, some say.

As a result, many professionals in those areas continue to chip the material out.

But even in such locales, some believe this process should be avoided. “If you go in with a jackhammer and start taking away the plaster, which eventually removes the gunite or shotcrete, the shell just gets thinner and thinner,” says Peter Langevin, CEO of Simply Pools in Fountain Valley, Calif. “What happens then is that the pool is more likely to crack at the end of the day.”

Because of this, some companies have chosen to use sand-blasters to etch the existing surface, making it rough enough for bonding but smoother than if it were chipped out. Some firms have invested in a newer, albeit more expensive, solution: water blasting.

“It’s the most intense pressure washer you’ve ever seen,” says Shawn Still, general manager of Olympic Pool Plastering in Norcross, Ga. “You have to carry it on a trailer, because it weighs about 4 tons. It will convert 3 gallons of water a minute into 40,000 pounds per square inch [of pressure].”

This method is similar to the sand blast, only cleaner. After water blasting a surface, crews use a power washer to blow splatter and debris back into the pool, acid wash the vessel, and pump everything out. “You’re not shoveling out sand, wheelbarrowing it out or hauling it off to a dump,” says Dave Schilli, president of St. Louis-based Schilli Plastering Co. Inc.

The pressure also will blow out the delaminated or hollow areas.

Some professionals believe the surface etching is enough to properly bond to the new coat of material, while others will add a bond coat.

“The manufacturer of the water blaster says you don’t really need to bond coat, because it’s rough enough,” Schilli says. “But for the minimal amount of extra money that you spend to put a bond coat on, why take a chance?”

However, this option is a significant investment — more than $100,000, or in some cases topping $200,000 — and it can be dangerous. Workers must wear body armor head to toe. “It’s not something that you hand to the average bear,” Langevin says. “There has to be some training involved.”