Hi, Any one have ideas on how to etch out a copper core from a platinum
tube? The tube is about 4mm dia. on one end and 2.8mm dia. on the
other. I have tried pure nitric acid cold and ferric chloride cold.
The nitric works but takes weeks. The ferric chloride works but is
still not through after weeks. I think ether would work if I agitated
them.But I don’t want to boil them, any ideas?