Copper and Bright Dips
Can you suggest a good formulation for bright dipping of copper alloys? I require a bright dip that will give me good polishing of the copper surface.
Q. Can you suggest a good formulation for bright dipping of copper alloys? I require a bright dip that will give me good polishing of the copper surface. S.L.
A. There are many different formulations for bright dipping of copper and copper alloys. Almost all of the classic formulations involve the use of sulfuric acid chromic acid and nitric acid. If you are looking for a formulation that will give you greater smoothing, a different formulation should be used. The table below shows a typical bath that will give you a very smooth bright finish.
| Component | Concentration |
|---|---|
| Nitric acid (1.42 specific gravity) | 20% |
| Acetic acid (1.05 specific gravity) | 25% |
| Phosphoric acid (1.70 specific gravity) | 55% |
| Hydrochloric acid | 0.5% |
| Operating Conditions | Range |
| Temperature | 185-190°F |
| Time | 3-5 min |
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