So. This began like so many of the new things I try. I finally got the things out to try something I've been meaning to experiment with for ages. In this case it was to create a verdigris patina using sawdust and vinegar. No ammonia since the only ammonia I had nearby was cat pee, which I know can be used but I didn't want to go there. Also added a little salt after a while.
As I hadn't done this before, I didn't know how long it'd take or how much vinegar to add. In the end I think that combination led up to the results you see here. First, kept adding vinegar because I felt the process was just so slow. Then I forgot about the jar. When I got in out and inspected the pieces of copper, brass and bronze I'd put in there, I discovered that the brass was not only heavily patinated in various colours (more yellow than verdigris), but the brass had begun to etch.
These two pics above are of a 25 mm brass blank (from Vintaj actually, so it had a brown patina initially which was stripped by the vinegar). I left the front as I found it, but the back (first pic) was polished using extra fine steel wool, removing the patina and exposing the lovely mottled pattern underneath. That's the pattern created by the vinegar etch.
These to blanks are brass (left) and bronze (right). I added the bronze tags much later than the brass blank so you can't compare the two and make any assumptions about brass versus bronze here. Also, the bronze tag was more exposed to the salt than the brass.
After slightly polishing with steel wool, I added some alchol inks to this brass stamping. I used a teal blue ink, dabbed it and added a bit more, which was also dabbed and swiped off. Then I added a small drop of reddish ink on the flower, dabbed and swiped it. It's not perfect and I'll probably add and remove yet more ink before sealing it.
I was quite pleased with the etch pattern on the brass so after I'd discovered it, I began googling "etching metal with vinegar". This is definitely something I'll do again!
So, did you have a ratio of sawdust to vinegar? This is such an interesting look. I agree the etching is a keeper. I really love the patina effects too.
ReplyDeleteIt's hard to say anything exact, but it was enough apple cider vinegar [the only vinegar I had] to dampen the sawdust and then I added a dash, say 2 or 3 times over time so the sawdust remained pretty moist -- and probably slightly concentrated as there was a little "steam" I let out every time I opened the jar. Not so much that the sawdust was wet or swimming in the liquid, but enough to keep it nice and moist. I put the jar (with a tight lid on) in the window on a sunny day so the heat would accelerate the process.
ReplyDeleteI'm going to do a much more controlled experiment next time. Not just using sawdust but also just putting the brass in a bowl of vinegar (or vinegar and salt, as mentioned on one website I found). And I'm going to buy some spirit vinegar (ättika, 24 %) too as see if I can use that now that I'm almost running out of apple cider vinegar. Perhaps try to do some patterns on steel to: when I googled it, I found out vinegar etching is used on steel blades on knives and swords.
If you're curious, here's some interesting sites I've found mentioneing vinegar etching:
http://www.ganoksin.com/borisat/nenam/applying_patination.htm (under Moistened shavings)
http://www.knivesforum.com/knivesforum/viewtopic.php?t=33
http://www.ehow.com/how_8122638_do-vinegar-metal-etching.html