MAR NTB BLACK is an electroplating process that will produce a uniform, adherent, decorative and functional rich black finish on all substrates that will accept an electroplate. The deposit can also be relieved to produce a variety of antique finishes.


  • Produces a uniform-rich black decorative finish on bright nickel, brass, bronze, copper, silver and other metals.
  • Can be relieved to produce pewter, Flemish, Old English and brownish-black finishes on brass, bronze, copper and silver wares.
  • Does not contain arsenic.
  • Very adherent coating.
  • Provides good corrosion and abrasion protection.
  • Coating can be lacquered to enhance and deepen the finish.


TANKS: Mild steel or stainless steel is suitable.
ANODES: Mild steel or stainless steel is suitable.
HEATING AND COOLING If heating and or cooling is required, heaters and coils should be fabricated from mild steel or stainless steel insulated from the rectifier power.
POWER SOURCE: Typically a 6 volt DC power adequately sized to provide 5 – 60 amperes per square foot.
VENTILATION: Consult local environmental agencies.
pH METER: Electronic or paper pH readings are required.

WARRANTY AND DISCLAIMER: This information is based on our experience and is, to the best of our knowledge, true and accurate. MAR-Tech Holdings Inc. gives no warranty, expressed or implied and the products are sold upon condition that the purchasers will make their own tests to determine the quality and suitability of the product. Any information or suggestions are given without warranty of any kind and the purchasers are solely responsible any loss arising from the use of such information.


MAR NTB BLACK: Component used for make up and replenishment.

SODIUM CYANIDE: Component used for make up and replenishment.

MAR NTB BLACK 48 g/L 25-55 g/L
SODIUM CYANIDE 72 g/L 60-80 g/l
pH 12.0-13.0
TEMPERATURE 65-75°C (150-170°F)

Sodium Cyanide and MAR NTB BLACK are replenished at the ratio of 3:1 based on free cyanide analysis. (See Control below)

  1. To a cleaned tank, add warm water to 3/4 of the final volume.
  2. Slowly add and dissolve Sodium Cyanide.
  3. Slowly add and dissolve MAR NTB BLACK.
  4. Ensure all the chemicals are properly dissolved and adjust to required volume.



10% Potassium iodide solution.

Standard 0.1N Silver nitrate solution


  1. Pipet a 2 ml sample into a 250 ml Erlenmeyer flask.
  2. Add 15 mls 10% Potassium iodide solution.
  3. Titrate with 0.1 N silver nitrate solution until a faint yellow permanent turbidity is present.


(mls of 0.1 N silver nitrate titrated) x 4.95 = g/L of free sodium cyanide

The replenishment ratio of Sodium Cyanide: MAR NTB BLACK should be 3:1

i.e.: For every 3 g/L of Sodium Cyanide required, add also 1 g/L of MAR NTB BLACK


Hull Cell testing parameters:

Hull cell anode: Stainless steel
Hull Cell cathode: Cleaned, bright brass panel
Temperature: 68-74°C (155-165°F)
Current: 2 amps
Time: 2 minutes, without agitation.

The black deposit should be uniform from 2-80 amps per square foot.

Poor Coverage in low current density: Low MAR NTB BLACK concentration Low free cyanide concentration pH too high
Slow Deposition Rate: High free cyanide concentration Low MAR NTB BLACK concentration
No Deposition: High carbonate concentration Very high free cyanide concentration Metallic contamination (copper, zinc or chrome) Solution over-heated
Brown/grayish high current density: Low free cyanide concentration
Low MAR NTB BLACK concentration


Consult the individual Material Safety Data Sheets (MSDS) covering MAR NTB BLACK for complete information.

For the MAR NTB BLACK additive and the MAR NTB BLACK working plating solution, handling is recommended using chemical goggles or a full face shield, as well as protective clothing (e.g., neoprene gloves and boots, acid resistant apron or suit and hat). Prevent body or eye contact with these materials. Skin contact or inhalation of the additives or the working bath, including mists, should be avoided. A NIOSH/MSHA approved respirator should be used, as necessary. Any pouring or pumping of the solution or its additives should be designed to minimize misting or splashing. Always wash hands thoroughly after handling.

The handling of nickel salts in crystalline form and the SODIUM CYANIDE or plating solution containing nickel and SODIUM CYANIDE may cause irritation to the eyes and skin AND DEATH. Inhalation of the dust, vapours or mists may be irritating to the upper respiratory tract. May cause skin sensitization, resulting in chronic eczema, also known as "nickel itch" ALONG WITH DEATH.

Adequate measure must be taken to protect workers from eye and skin contact and to prevent the inhalation of dust or mists. The use of the following protective equipment is recommended: Chemical safety goggles or face shield, rubber gloves, protective clothing and shoes. Work in a well-ventilated area. If local exhaust ventilation is inadequate to maintain atmospheric concentrations below the TLV, approved respiratory protection is recommended. Wash thoroughly after handling chemicals and at the end of the work period. Launder contaminated clothing before reuse.

Please note that the information above for this chemical is partial. Click the button below to request full technical information sheet.
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