Birchwood Casey Liquid Patinas All are packaged in a concentrated form - dilute up to 50% with distilled water. All Birchwood patinas are considered traditional patinas that will age or darken metal. Most of these patinas are sold concentrated and should be diluted with distilled water (up to 50%) before use. Once diluted, one gallon of Birchwood Liquid Patina generally covers 200 sq. ft. Liquid solutions for Bronze, Brass, and Copper (concentrated): M-38 is a spray, brush or immersion Brown Antiquing Solution. M-24 is a spray or brush Black Antiquing Solution. M-20 is the same Black Antiquing Solution as M-24, but is made for an immersion (dipping) process. Liquid solutions for Iron and Steel (concentrated): PC-9 Presto Black (Gun Bluing) spray, brush, or immersion. BST4 Presto Black room temperature, brush-on solution. Plum Brown Barrel Finish (32oz. only). Liquid solution for Aluminum (concentrated): A-14 Aluma Black spray or brush Black Antiquing Solution for Aluminum. Liquid solution for Stainless Steel (ready to use formula): SSB Presto Black for Stainless Steel.
