|in short, it's the vapors that do the reaction on the metal- makes it grow a surface of blue crud aka "patina"|
I thought it might be interesting for my readers to see as well- give a peek "inside the studio" for non-metalsmiths as well.....so- without further ado...... Here's a quick look at putting a beautifully textured blue patina on copper-
|put your clean copper in the bag, cover it with the sawdust solution and SEAL the bag shut to keep the ammonia vapors inside, doing their magic...every hour or so go and check on it...|
Once I'm happy with the patina color I like to seal my patinas with either clear butcher's wax , renaissance wax, or a light application of clear spraypaint/fixitive (very light application only)
it's best to experiment with patinas on small sample pieces before you dive in and try to patina an important piece-
remember to use good ventilation, the fumes are really strong!
This is just one way to develop color on metal- there are many tutorials online and in books- There are many patina recipes and techniques- and many opinions... :-) it's up to you to decide which works for you, and how you want to use it.
Patinas are surface color only- they don't go "into" the metal, they cling to the surface- When you design a piece for patina make sure you don't use them for anything that will get lots of wear and tear (like a ring) or, if you do put it on an exposed area, you need to put a protective structure on top of it to avoid abrasion...
take lots of notes, do some variations (use distilled water/add more/less salt/ammonia, change sawdust type to different coarseness/wood type) and enjoy watching your metals morph into something beautifully colorful!
|top right piece is unpatinaed copper- then clockwise, blue patinaed copper with liver of sulfur base, the three samples on the left are all copper with an ammonia, salt and sawdust patina.|
may the flux be with you- ciao- Maureen