| previous by date | index | next by date |
| previous in topic | topic list | next in topic |
> It should be blue for proper etching. You need to add some concentratedNO, not BLUE! It should be green. If it is blue you have no HCl and it
>
> H2O2, to oxidise the green cuprous chloride to cupric chloride. Adding
> the
>
> 3% H2O2 will make the solution too dilute. Or, just mix it fresh each
> time.
>
>
> Leon