White (opaque) spots in newly applied sealer

Q. Recently had a re-seal job done on a 3 year old stamped concrete walkway/driveway. The last section of the job had opaque almost white spots all through it.

To the touch they appeared to be kind of rubbery small parts of the sealer not adhering very well to the concrete surface. Contractors solution was to simply put more sealer and stain over that section of the job. Looks better, but I am worried about spots peeling up later.

Do I need to be concerned? Is there a better solution? I am told by the contractor it is a "hybrid, breathable sealer, water base". Surface was steam and hydro blasted before sealing. - Thanks

A. Sounds like you had some blisters form when the new sealer was applied. This isn't uncommon. One solution is to apply more sealer to soften the dried sealer, re-wetting it and letting it lay back down.

Another solution is to spray some xylene on the blistered area. This solvent will also re-wet the sealer and allow it to dry properly.

Blisters form when sealer is applied too thick or the sealer drys too fast. Air escaping from the pores of the concrete when the sealer is settling into them gets trapped and forms these blisters.

After the sealer drys, the blisters become brittle and break easily. If they didn't re-appear, you should be ok.

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