If you work with metal and use liver of sulphur for oxidation you may know that this work well for copper and silver but not really good if at all for brass. Still, I like this small brass stampings. They are sturdy, cute and also cheap. I bought them on a craft fair and to be honest, there is never a great selection but the dragon fly and frog is cute enough.
Cute... but bright golden yellow shiny (aka as not mine)...
Here is how the looked at the beginning.
How I got there? By heating them up with a torch! Brass being mostly a mixture between tin and copper heats up quite easily. You have to be careful how to treat it (and yes, it is easy to make brass head pins, the only necessary trick is to flux the wire before!) and not to overdo it but also to heat enough. Mh... but to be honest... you don't have to be too careful. These little brass stampings are not expensive and there is not a lot that can really go wrong.
If it does not oxidise enough after heating/pickling, just heat them up again. If you heated too much (which is not soooo fast done with a micro torch, I didn't manage until now!), it is just melted. Since the small stampings are not expensive, that is okay.
On the upper dragon flies I got a nice heat patina. Lovely! Now I have to try to preserve it (I know, I know... not really easy/possible). On the middle right butterfly you can see how flakes fall of the stamping after the heating. This is mostly tin while the surface now has more coppery tone. And yes, that means more copper on the surface!
Just a mild pickle (I use normal household vinegar and salt and just add a bit of boiling water to get it warm) and then you can use your liver of sulphur!
Look at the pink shades...! If only I could preserve them...!
So there it was. My simple and easy trick to get my brass stamping black! (or just a little bit duller, darker, more colourful ^^)
I am posting this because I stumbled over so many postings online from people trying to get their brass. Originally I thought how easy this was, I mean after all this is also how it functions with the oxidation of brass after being etched (you get more copper at the surface on the etched areas because tin and copper react different). Treating now a metal mixture with heat where both kinds of metal have different melting temperatures just was a small jump for me (first thing I did after is was not working with just really hot water and liver of sulphur). But then I thought if so many people are trying to do this: Here is my trick and I hope it may be helpful to you :)