Birchwood Technologies Antique Black® M20 Immersion

Article number: 74M20
Availability: In stock (4)

ANTIQUE BLACK M20 Antiquing Solution

Operating Instructions


ANTIQUE BLACK M20 Antiquing solution is a general purpose browning and blackening solution for use on copper, brass & bronze surfaces, and works on both solid and electroplated parts. Supplied as a liquid concentrate, the product is diluted with water to make up an immersion solution that operates at room temperature to produce medium-dark browns and black finishes. The finish can be highlighted for pleasing black, brown or US10B finishes.



  • Bath Make-Up Concentration                       20-25% by volume for dark brown/black

                                                                        10-15% by volume for lighter brown shades.

  • Operating Temperature                                 Room Temperature
  • Equipment Construction                               Acid-proof tank: plastic or PVC lined.
  • Ventilation                                                    None required. No fumes.
  • Filtration                                                       Desirable for production-scale tanks.

                                                                          Use acid-proof pump and 50-100 micron        polypropylene filter element.



  1. CLEAN and degrease the parts for five minutes in SAFE SCRUB M Multi-Metal liquid cleaner, mixed at 10-20% by volume; 100-140° Or, use bead blast techniques. OR, electroplate parts, applying a minimum thickness of 0.0002”.
  2. RINSE in clean water tank for 30 seconds, to remove cleaner/plating
  3. (Optional) REMOVE TARNISH and neutralize residual plating cyanide by immersing parts in 5% sulfuric acid or sulfuric acid salts; Room Temp; 1 RINSE in clean water for 30 seconds.
  4. APPLY ANTIQUE FINISH by immersing parts in ANTIQUE BLACK M20 solution for 1-3 minutes, as needed, to produce the desired Agitate parts gently to assure solution contact with all surfaces.
  5. RINSE in clean water tank for 20
  6. DRY the parts and apply lacquer. Or, HIGHLIGHT the finish with an abrasive or polishing wheel or in a vibratory finisher. Apply protective topcoat, such as clear lacquer, wax or Note: the topcoat will enhance and darken the color of the finish as it is absorbed. The final color should be judged after the topcoat is applied.



The ANTIQUE BLACK M20 bath can be operated as a permanent bath in the process line and is controlled by total acid titration, or by using the CCK Color Change Test Kit (available from Birchwood Technologies). Other methods, such as total acid titration or Atomic Absorption (with a selenium lamp) may also be used. Maintain the bath strength at 80% of original make-up or higher. Keep tank covered when not in use to minimize contamination and evaporation.

Before Using This Product – Please Read, Understand and Follow all the Precautions shown on the Product Label and on the Safety Data Sheet.


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