Tuesday, July 29, 2014

Tripped-Up Tuesdays: Holy Reverse Redox, Batman! How not to use baking soda and aluminum to remove tarnish from silver

With a few exceptions, nothing beats the safety of a bicarbonate/aluminum foil/water bath for removing tarnish from silver.  If you aren't careful however, things can go very wrong:

It started innocently enough:

Several objects covered with baking soda, ready for the hot water bath.

But within moments, this happened:

Notice that several of these sterling beads have actually turned black, not shiny silver!
It turns out there were several potential culprits:

The two Art Deco "Bubble" Necklaces on the left were strung on nickle chain, not silver plate as I had been told by the vendor, and a nickle safety chain had been attached to the amethyst bracelet on the right. In addition, a fourth necklace had been strung on uncoated metal wire of unknown type and crimped with what appeared to be zinc metal.

Tarnish is caused when hydrogen sulfide reacts with surface silver to form silver sulfide. This process can be reversed in a classic redox electrochemical reaction by placing silver (the cathode) in a salt water bath (the baking soda dissolved in water) with a metal that has more affinity for sulfur than silver has (here, aluminum --the anode).  The two metals need to be in contact with one another. The process messed up here because I inadvertently placed a tarnished metal into the bath that actually had less affinity for sulfur than did the silver.  The problem was remedied easily enough--I just needed to repeat my saltwater bath making sure that nothing other than silver and aluminum were in the chemical mix.  I have also started to use this:

A neodymium magnet can be used to detect any unexpected magnetic metals in your jewelry (primarily nickel).  I also now create separate aluminum "boats" for each piece of jewelry so that if the redox reaction does go wrong, it will at least be limited to a single piece.

Tuesday, July 22, 2014

Tripped-Up Tuesday: How not to stage a necklace

Everyone knows that colors side by side on the colorwheel look less intense than when you pair the same color to its opposite or against white. However, I once saw an amethyst pendant photographed against an intense, luminous pinky-purple background, and it looked amazing. I wanted to replicate that look using a tomato-red coral necklace and reflective acrylic (one red, one fluorescent pink). Here are the results:

I think we can all agree this is not the best way to stage a necklace!


There are many great resources for learning how to photograph jewelry. My personal favorites are:
  •  Derrick Sutton's "How to Sell Your Crafts Online: A Step-by-Step Guide to Successful Sales on Etsy and Beyond;"
  • Marsha Collier's "E-bay Business All-in-One for Dummies;"
  • and this You-tube link: How to Photograph Jewelry by the Jewelry Making Professor

For the record, none of them suggested using tomato red backgrounds for tomato red necklaces. I especially love the low cost light box suggested by the Professor!

Disclaimer:  I haven't turned on Google AdsSense.  If I recommend it, it's because I *like* it!