Problem after Sealed Concrete

Hey everyone, I’m hoping someone on this forum will be able to help me.

We recently pressure washed some concrete around a pool. The following afternoon we sealed it with Ghostshield 9500, which is a water-based penetrating sealer.

It was about 60 degrees when we sealed it, and it go to about 40 degrees the following night.

The next day the customer sent us photos of portions of the concrete that were white and pasty looking.

We have tried applying pressure washing with no luck, applying xylene with no luck, reapplying the same sealer and scrubbing and then wiping it off, with no luck, and applying an acetone with no luck.

One contractor told me these white patches will go away when the weather gets hot. Is that true?

If not, how do I fix this?! Thanks in advance.

was the patio previously sealed? Maybe you applied sealer on top of sealer that wasn’t able to penetrate. Call the manufacturer and send them those pics, they probably have an answer

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Some of the water-based penetrating sealers can occasionally push efflorescence to the surface. (And that’s not a defect in the sealer.) So it could be that.

GhostShield has a pretty good support line, though, so I’d call them and have those pics on hand.

Always remember the manufacturer has likely encountered whatever issue you’re having (or has had its customers encounter the issue) and they’ll know the best plan of attack. Make sure to tell them everything you’ve tried so far as those chems might’ve affected the sealer.

Why in the world would you do all that stuff to it before you knew a definitive solution? That concrete is going to be so jacked up now that it may never be right.

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I got a hold of the manufacturer. He told me that we must have put too much Ghostshield 9500 on the surface. He said that the sealer will react to the carbon dioxide in the air and produce white crystals on the surface of the concrete. But he also said they should fade and disappear over time with the rain and wind and elements. Has anyone heard the same thing before?

Are you a professional concrete sealer? If you are “just” a pressure washing company, then you bit off more than you can chew and I bet insurance will not cover you.

Personally, I would never offer a service that I don’t understand. I clean stuff, period. Anything more I refer to a local pro that I respect.

Perhaps this is a hard lesson learned, but, I don’t think you should learn at the customers expense.

Yes, the product I use will do the same thing if you use too much. But normally using a brush on it will remove it. Kinda surprised a surface cleaner wouldn’t work for you.

If you have a hot water unit, that would help a lot.

That’s usually more a problem with pavers, that have an uneven surface and joints and most the manf tell you not to let puddle and to either roll it or use a blower. I’m not so sure on concrete, but I’ve got a 3 yr old paver project that I missed blowing out a joint and it’s still there.

Concrete I suppose would be the same if you have some areas that let it accumulate just slightly. Did they have any recs on what to do at this stage? Sorry you had the problem, good luck with it.

Yep, water based sealers too thick to be absorbed (maybe caused by the presence of a previous sealer in some areas, probably of the solvent based variety). Have had to scrape some areas once or twice. Our prior issues were the grooves on stamped concrete where we didn’t roll/blow it, like @Racer said.