How to remove melted plastic stains from concrete?
Estimated Reading Time: 2 MinutesQ. Unfortunately, I had a decorative Halloween candle holder with the fake light in it turned on. Part of the black plastic from the candle holder melted from the heat of the fireplace and ran down the mantel. I cannot get the stain out of the cast concrete. Do you have a solution to this?
A. That Halloween decoration left you with more trick than treat. Since the discoloration is caused by melted plastic, it may take a strong solvent, such as varnish remover (available at home improvement stores), to remove the stain. Scrub the stain with a nylon scrub brush and the solvent. As with any strong chemical, be sure to follow the recommended safety precautions on the bottle. Test the solvent on an inconspicuous area first, just in case there are any dyes in the concrete that may be affected by the solvent.
If the stain is not removed, try creating a poultice with the solvent and an absorbent medium, such as flour or diatomaceous earth. A poultice draws the stain out of the stone over time. For detailed, step-by-step instructions on how to mix and apply a poultice correctly, check out our free Stain Management App.
If both methods fail, a final option would be to lightly grind the surface of the concrete to remove the stained layer, but this should be a last resort, as it will alter the texture and appearance of the mantel. This should be performed by a stone restoration contractor who can match the appearance of the affected area as closely as possible to the surrounding concrete. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.
ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]