Things You'll Need
2 stiff brushes (not wire)
Lint free rag
In ideal world, construction and remodeling would always go smoothly. Mortar would be brushed off when dried on manufactured stone. We would never give in to the temptation to wipe off that mortar while it's still wet, causing a smear. Ideal conditions do not usually exist. When you have given in to that instinct to wipe while wet, you have a very ugly smear or faded "cloudy" area on your manufactured stone. So here is how to get rid of it without damaging your stone.
Allow the mortar to completely dry. Do not keep wiping at wet mortar. Leave it for the day and come back tomorrow, allowing the mortar to dry overnight.
Squirt a few drops of dish detergent in a container and add warm water. Swish the container until the majority of the bubbles have popped and disappeared. Put the detergent solution aside.
Take one of the stiff brushes and rub the bristles back and forth across the smear. It is easier to scrub gently if you position the brush at an angle so the side of the bristles are in contact with the manufactured stone. Remove as much of the smear as possible with this dry method.
Wipe the area with the rag to remove any dust from the stone surface.
Dip the second brush in the detergent solution, thoroughly soaking the entire length of the bristles. Using the same method to scrub with the side of the bristles, apply the detergent to the stone, scrubbing carefully. Scrub the entire area.
Repeat the scrubbing with plain water. Allow the area to dry completely and repeat scrubbing with the detergent solution if needed.
Larger brushes will scrub an area faster, but you will have less control over crevices and natural dips in the manufactured stone. Smaller brushes allow you to better follow the contour of the stone.
Keep in mind that manufactured stone is made of colored concrete. It may take a few scrubbings to remove the cloudy areas caused by the smear.
If the stain left by the smear is extensive, contact the stone manufacturer. Some manufacturers offer a stain kit. The kit will allow you to paint over the stain. This is a last ditch option as some stains may show through the paint.
Be careful to not scrape the stone with the ferrule, the metal area where the bristles attach to the brush.
Do not use a cleaning scrub brush. The bristles are too stiff and will scratch the surface.
Do not use an acid cleaner or a wire brush which will damage the surface of the stone.