"Could you explain more on how to make the mix with the copper wire? I like the idea of less corrosive fumes."

Cupric chloride is what that sounds like. If you mix hydrochloric acid and hydrogen peroxide, then etch copper, you end up with cupric chloride. As it gets overloaded with copper, it changes. Simply bubbling air through it to add oxygen, or adding a little more H2O2 converts it back to cupric chloride suitable for etching again.

James Newton kindly saved a lot of posts from here pertinent to making PCBs. From?

Hydrochloric acid and Hydrogen Peroxide aka Cupric Chloride

Chuck Knight says:?

"The recipe was simple. 2:1 ratio of H₂O₂?to HCL. The HCl was 20% concentration, in a toilet bowl cleaner called "The Works" that I purchased at WalMart for $0.94. The H₂O₂?was also from WalMart, from the pharmaceuticals section. Whatever they had...

The etchant works impossibly slow at first...threw in a sacrificial bit of copper wire, and let it dissolve all night. Once it turned from blue to emerald green, it worked beautifully for 4 boards. Took several hours to etch the boards. It did, however, turn into an ugly olive green that needed to be refreshed with a capful of H₂O₂, 3/4 of the way through the process."

Erik Knise advises: "At 20% concentration of HCL and 3% (standard over the counter pharmacy) H₂O₂?you should have a ratio of ~1:3 by weight (volume is about the same). So you would need 3 times as much H₂O₂?to HCL. The board should have etched within a few minutes."

DANGER:?With 20% HCL (from a pool supply) and 30% H₂O₂?(hard to find, try a chemical supply store) mixed 2:1, once a little of the copper gets into the solution, the copper will literally foam off the board and the etching will be done in a minute!?

?helps you design the perfect CuCl2 echant for your needs.

--
Steven Greenfield AE7HD

_._,_._,_

---