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PICKLE #4 is a general-purpose metal
activator and de-oxidizer containing fluoride. Used at room
temperature on steel, copper, brass and zinc.
PICKLE #4 is a free flowing mixture of dry
acids and is more convenient and safer to use than liquid
mineral acids. It does not produce the undesirable fumes
given off with strong acids. It is dissolved in water and
used at ambient temperatures to remove light to medium
surface rust from steel and to activate steel surfaces prior
to blackening with Black Oxide blackening solutions. Heavily
rusted surfaces may require elevated temperatures of 150°F
to 170°F. No venting required when used at ambient
temperatures. It is used following the water rinse after
cleaning the steel surfaces with
SP
DEGREASER.
PICKLE #4 is more moderate in its action on steel
surfaces than mineral acids and produces a uniformly active
surface.
PICKLE #4 is also used to activate zinc-plated surfaces,
die cast zinc surfaces, copper and copper alloy surfaces
prior to blackening, oxidizing, antiquing, chromating or
other finishing.
EQUIPMENT REQUIRED
PICKLE #4 solutions must be contained in acid-resistant
tanks and containers. Polypropylene, polyethylene, PVC or
rubber-lined steel are suitable. If heaters are required
they must be glass or Teflon coated.
SOLUTION MAKE-UP
| Metal |
Action |
Makeup & Use |
| Steel |
activation |
8 oz/gallon
30 to 60 second immersion |
| N/A |
rust removal |
16 to 32 oz/gallon
2 to 10 minutes immersion |
| Copper and its Alloys |
deoxidizing |
8 to 16 oz/gallon
30 to 60 seconds immersion |
Plated and die cast zinc
Lead/lead solder |
deoxidizing |
4 to 8 oz/gallon
30 seconds to 2 minutes immersion |
Residual PICKLE #4 solution must be removed with a
thorough cold-water rinse prior to further finishing.
SOLUTION CONTROL
The strength of the solution is maintained by small
periodic additions of PICKLE #4 salts. The solution is
dumped only when its effectiveness is diminished by
accumulation of metals, dirt, oil, etc. |