Mainstay DS-4 is a 100% solids epoxy tar coating that can be applied up to 0.100" (100 mils) in one or two multi-pass coats and is designed for use where corrosion is anticipated or known to be extremely active and aggressive (pH < 1.0, H₂S > 100 ppm). 100 mils or more is recommended for the most extremely corrosive locations in a collection system, such as in manholes near a force main, or in lift stations. DS-4 is also ideal for secondary containment applications where aggressive chemicals are often encountered.