DART 191 removes of smut and discoloration from surfaces after alkaline etching quickly and efficiently.  This highly concentrated liquid acidic product is also well suited for removal of silver metallic films from new stainless steel processing equipment, as well as the preparation of aluminum prior to anodizing, conversion coating, barrel finishing, welding, and more.  It can remove heat treat varnish as well as mill scale, and is ideal for preparing stainless steel for passivation.  This highly effective formulation contains no chromates, so it is safer to handle and use. 

Normally used at 5 to 50% by volume with water and ambient temperatures for most applications.Immersion time is typically 2 to 10 minutes depending upon the extent of heat scale, oxides, or smut present.Parts should be rinsed with clear, cold water to reduce tendency of aluminum surfaces to reoxidize.DART 191 is acceptable for use in food and beverage plants as an A3 acid cleaner in all departments.