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Q&As since 1989


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Rusting using acid

2005

Hi, I am a student and I would be most grateful if someone could give me a hand with this question:

If I was to use acid to rust copper to the extent that there are holes in it, how long would that take. Second of all, if I then take this pice of decayed metal to an environment to the sea and thus salt water will the decay continue to enlarge the holes created by the acid, and how long would that take to create.

Lets say I created a holes with the acid whivh was 20cm in diametre, then placed it in the stated environment, how long would it take for the hole to reach a diametre of 50cm.

Adam K.
- UK

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2005

Aabsolutely impossible to answer! Too many variables.
1. Copper corrodes, only iron bearing materials rust.
2. Dissolve would be a better term for removing enough metal to create a hole that big.
3. Sea water is very slow to attack copper. Before steel ships or iron clads, some ships were skinned with copper sheet because enough copper dissolved to kill any living organism that would normally grow on the hull which eliminated having to go into drydock or carrening to defoul the hull. The copper lasted for years.

James Watts
- Navarre, Florida