Do It Yourself Patio Finishes for Existing Concrete | Hunker
With the watering can, sprinkle the muriatic acid mixture onto the surface of the concrete patio. Work from the interior of the patio to the exterior. Watch the acid as it meets the concrete to ensure that bubbling occurs on contact. Let the acid sit on the concrete patio for 20 to 30 minutes once the entire patio surface is evenly covered.