BLACKENING CHEMICAL FOR METAL WORKING
Common Blackening Processes and Chemicals for Metal Working:
1. Hot Blackening:
. Chemicals: Typically involves using an alkaline aqueous solution at high temperatures.
. Process: The metal is dipped in a hot bath of sodium hydroxide, nitrates, and nitrites, which react with the metal surface to form a black oxide layer (magnetite, Fe3O4).
. Applications: Common for ferrous metals like steel and iron.
. Example Products: Birchwood Casey Presto Black® Hot Blackening, Precision Brand Products Black Oxide Kits.
2. Cold Blackening:
. Chemicals: Utilizes a room-temperature chemical bath, often containing selenous acid, copper compounds, and other proprietary agents.
. Process: The metal is cleaned, then immersed in the solution, where it reacts to form a thin, dark coating.
. Applications: Preferred for small parts, low-volume applications, or when a hot process isn't feasible.
. Example Products: Birchwood Casey Presto Black® Gel, Caswell Inc. Cold Blackening Kits.
Keywords
iron
Fe3O
steel
nitrites
nitrates
hot bath
magnetite
Chemicals
Caswell Inc
small parts
hot process
metal surface
METAL WORKING
selenous acid
ferrous metals
copper compounds
sodium hydroxide
Example Products
black oxide layer
high temperatures
thin, dark coating
BLACKENING CHEMICAL
Cold Blackening Kits
low-volume applications
other proprietary agents
alkaline aqueous solution
Common Blackening Processes
room-temperature chemical bath
Birchwood Casey Presto Black® Gel
Precision Brand Products Black Oxide Kits
Birchwood Casey Presto Black® Hot Blackening
