Selected Answers

From Michael Quaranta of OPERATIONS 40 on March 18, 2016:
Great exercise! What is the size and age of the c ...read more Great exercise! What is the size and age of the concrete? What is the estimated age of the visible oil stains? Prepare yourself for ASR. Email me and I'll show you pictures of a concrete surface with a large (aged) oil stain that is treated and coated with a water-based, water-clean-up epoxy that offers a minimum 10-year warranty. As for the previous advice here, I would not add any liquids, emulsifiers or solvents to address the oil stains. Email: operations40@att.net NOTE: Since this is an excellent, repeated coating interest article, I'd sure like to learn what was the final resolution on that warehouse concrete floor?

From Robert Cameron of PPG on March 18, 2016:
A biodegradable detergent cleaner/degreaser for ma ...read more A biodegradable detergent cleaner/degreaser for masonry should do the trick. Confirm with the coating supplier that the products used are compatible (usually a quick call or email covers it). Also, beware: some oils do attack the cement binder in concrete, so make sure the area to receive the coating is sound and that the coating is able to resist spills of this oil (as it may be likely to happen again). If you see exposed aggregate, this may be a sign of attack to the concrete, and may indicate a need for patching before coating to ensure a continuous, true surface for coating.

From Darell Chamberlain of C. Darell & Assoc. Inc. on March 16, 2016:
Use a microbial enzyme cleaning solution. This wil ...read more Use a microbial enzyme cleaning solution. This will remove all the oil, carbon, and organic materials.

From Timothy Knell of Shore Corporation on March 14, 2016:
Depending on the time you have between when you ca ...read more Depending on the time you have between when you can access the floor and when it has to be completely cleaned, you can pretreat the spots with a non-emulsifying cleane,r which will push oils to the surface or apply a bacteria-based product to biodegrade them. Afterwards,use a strong alkaline degreaser / emulsifier to remove all residues and dirt.

From Dave Helmholdt of Repcolite Paints on March 14, 2016:
Use an oil and grease emulsifier. This will help c ...read more Use an oil and grease emulsifier. This will help clean the surface while also pulling oil out of the concrete. After you have cleaned the floor, than you can follow up with additional prep such as grinding or shotblasting.

From Sarah Geary of RockTred on March 14, 2016:
http://www.paintsquare.com/psf/?fuseaction=answer& ...read more http://www.paintsquare.com/psf/?fuseaction=answer&psfID=259.

Editor's Note: The question was asked in 2014 on PaintSquare News. We repeat it here because of the obvious interest it generated then and continues to generate now. Follow the link above to see the responses in 2014.