I have an existing concrete patio that the previous home owners painted with an acrylic concrete stain by behr. Parts of it was not painted with were under the hot tub which is now removed. A section of the patio was removed and replaced for some drainage work. That new concrete section is showing white spots from the curing process. So with all the various conditions I have what is the best product to use to recoat this patio and last for a long time.