Mansol Blackening Salts

Blackening Salts for Mild Steel is a caustic free flowing powder producing a “Black Oxide” finish on mild steel as a result of conversion of the metal surface to Iron III Oxide (Fe₃O₄).

Applications

The decorative black finish produced from the use of Blackening Salts has no dimensional change making it ideal for Machine Tool/Armament or Instrument Manufacturers.

• • Blackening Salts: 1600g/l

N.B.: Always Wear eye/face protection and rubber gloves.

(Refer to product sds BEFORE using /making up baths)

• Tank Make-up

• • Start with 15 to 20cm water in the bath, slowly add Blackening Salts under constant stirring until no more will dissolve; Care, this will generate large quantities of heat!

Next add water to raise level to ~20 cm off the top of the small tank and ~25 cm off the top of the large tank.

• • Slowly and carefully add the remainder of the Blackening Salts, whilst stirring, to each tank until material has dissolved.

• • Tank A: Heat the solution and bring to the boil. Record the temperature with an accurate thermometer. If the temperature recorded is above 143 C add water SLOWLY and with care to lower the boiling point of the solution. If the boiling point is below 143 C add Blackening Salts, in small quantities, to raise concentration and boiling point.

• Operating Procedure

• • Mansol BS100 Cleaners
  • De-Rust/Descale (Optional)
  • Water Rinse (x 2)
  • Blackening Salts @ 143 C (5 – 10 min)              

• • Cold water rinse (x 2)
  • Hot water rinse (To achieve “flash drying”)
  • Dewatering Oil Rinse (Mansol Dewatering Oil)

• Tank Maintenance

• • Water and salts will be lost from the bath by evaporation and “drag out”. The solution should be maintained at a constant volume and boiling point by the addition of Blackening Salts and/or water as required.

• • The correct concentration of Blackening Salts is important to maintain the performance of the solution.

• • Do not make any adjustments to the solution whilst components are in process.

• • Extreme care is required when making any adjustments. N.B. To avoid “spluttering” when adding water, the bath may be cooled to 100C and then re-heated.

• General

• • Components are brown/green: Solution too strong
  • Components are grey: Solution too weak
  • “Iridescent” wine colour: Longer immersion time required
  • Agitate components to allow “touching” surfaces to be converted
  • “Patching” of surface: Component not cleaned sufficiently prior to treatment
  • Temperature control is critical for process