| 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 |
| |
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 mins 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.
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