Saturday, August 11, 2012

Sisyphus shops at Target?


Sisyphus must have been shopping Sunday, leaving his boulder parked in the Target lot.  Alas, the guys don't posses the strength of the Greek gods required to move it, but they gave it a valiant effort anyway.


In other news, I've been experimenting again, this time with  electro-etching, which is using electricity to move metal ions from one electrode to another.  If you use something to mask part of the donor electrode surface, it is possible to etch a pattern in the metal.  I believe print-makers sometimes use this technique to create metal plates for a printing press.  Electroetching can also be used to make printed circuit boards as an alternative to the more traditional chemical (Ferric Chloride) etch method.  In my case, I am interested in trying this out to to create patterned metal for jewelry components.

A really great gentleman I know from work is an electronics whiz and is quite an experimentalist himself. I should mention that he built his very own pipe organ, BY HAND, every single metal and wooden piece he carefully designed, fabricated and assembled in his workshop.  So I was thrilled when he agreed to help me put together a "proof of concept" experiment to try electro-etching at home.  This is him using a portable, butane fueled, soldering iron to make the connections to his flea market sourced power source.


While he was working on the power source, I was prepping the etch bath and copper blank.

I had a few pieces of flat  copper sheet shapes left over from the patina experiment (Laura was kind enough to leave a few pieces for me to play with).  I measured the thickness as 1mm, which equates to 18 gauge sheet metal.  The piece I wanted to etch was then scrubbed with a green sponge scrubbie and soaked in a hot vineagar and salt solution for about 10 minutes.  After carefully drying and being sure not to get any skin oil on the piece I applied a couple of press and stick vinyl stencils to the copper as a mask.
There are many and arguably better ways to apply a pattern mask for this type of application, however I already had these on hand and haven't found a good use for them for at least a year now, they just sit on my desk taunting my muse with the smell of unused potential.

The etch bath was simply a salt saturated vinegar solution.  This is not the best recommended solution, but this was just proof of concept and again, I had the ingredients on hand (are you sensing a theme yet?, it's "what I had on hand")
  and now the fun begins, yippee!  We connected the positive side of the power supply DC output to the "donor" piece of pattern masked copper (the crescent shaped piece in the container photo above).  The other, negative, side of the power supply was connected to a scrap piece of stainless steel (the thing that looks like a small ladder in the container photo below).


 We also put Andy's fabulous vintage ammeter in the circuit to measure how much current the circuit was producing, just about 2amps.  By adjusting the power supply voltage output, we could get it to about 1amp, but not much lower.
 

and now the magic begins, there was immediate evidence of electro-etching as the donor piece fizzed away and greenish goo started to collect on the recipient piece (the stainless steel piece connected to the negative side).

we left it going for about 45 minutes or so, then pulled the plug.  Definitely a successful proof of concept.  It didn't produce a deep etch, or "bite", however it clearly worked.  One of the stencils came loose about halfway, so only one pattern is apparent.


A very promising technique.  Next time I will use a copper sulfate solution and take better notes about amperage and time to try to dial in an optimal set up.