silveretching01-1

Safer Silver Etching

March 27, 2014 , In: General, Metalsmithing, Tutorials
0

I have been desperate to try out silver etching for a long time. I love working with etched copper and wanted to create the same effects on sterling. The only problem was the chemicals involved in the process. Usually silver is etched using Nitric acid, a highly toxic and corrosive liquid which emits harmful gases while eating away at the metal. As much as I love undertaking dangerous activities, the thoughts of messing around with strong acid worry me. So I’ve been looking for a safer alternative. 

 

My research started off looking in to different solutions for stripping the silver, I found ferric nitrate and silver nitrate. I have silver nitrate in my ever growing collection of raw materials for glaze mixing so I decided to go with that. Silver Nitrate is still a hazardous substance and should be treated with care. I wear a mask when mixing it and rubber gloves. Silver Nitrate won’t do any harm if it touches your skin as a diluted solution, it’s actually used for certain skin treatments, but it will stain your hands a lovely shade of brown, it won’t be apparent at first, but it’s light sensitive so the minute you go out in the sun, they will change colour… ask me how I know! It is also dangerous if you get it in your eyes. Always take proper safety precautions and use common sense!

 

To etch with silver nitrate you also need a power source and a few other bits and bobs which I will tell you about as we go along. The power source listed was a bench supply, I have one of those, but I wanted to try and see if the process worked the same as salt water etching, so I’m going battery powered!

 

So to start, I cut as close to a circle of silver as I could, and also cut a dreamcatcher design in vinyl to use as a resist. You can use all sorts of things to mask with, pnp paper, stop out fluid, and ironed on toner. But I haven’t had chance to test how they work yet, so I went with what I know! 

 

Here’s the silver ready to go with the areas I don’t want to be etched masked out. I also masked the back of the disc.

 

 

 

The silver piece needs to be suspended in the silver nitrate solution, so for this I used Aluminium wire wrapped around the edge so it was touching the silver and taped it on from the back.

 

The other supplies needed are a steel bowl, (I used a small water bowl from the pet shop) a D size battery and holder with terminals (not sure of the proper name for that!), a couple of crocodile clips attached to the positive and negative of the holder with copper wire, and a bamboo skewer.

 

100ml of water was put in to the bowl and I added 1 gram of silver nitrate. Always add dry ingredients to wet to save splashes! Stir with an old spoon until the crystals have dissolved, and the mix is ready to go. 

 

The bamboo skewer is placed across the bowl and the aluminium wire bent around it to suspend the silver so that it’s fully submerged, but not touching the metal of the bowl. 

 

 

 

The negative wire from the battery is clamped on to the metal bowl, and the positive is connected to the aluminium wire to complete the circuit. Once both crocodile clips are attached to the battery, the etching process will start. It’s not as fast a process as if you were using nitric acid. I left the silver in for about an hour to get a shallow etch, it could have probably done with twice that! 

 
 
 
 

If the etch is working you will see a grey fur appearing on the wire and the silver. You can see here how dirty the solution gets as it etches. To reuse it, you need to strain all the bits out and pour it into a bottle for storage. (I swapped the wire over before this picture for copper, as I wasn’t sure if it was working. I didn’t realise that the aluminium wire was coated, so after sanding it off, I switched back and it worked fine!)

 

I’ve been looking around for information to dispose of the solution and bits safely. When you’re finished with it, the solution can be neutralised using table salt. The advice given is to add salt until no more white precipitate is produced and then hand it over to your local hazardous waste disposal facility, the same as you would with ferric chloride used for copper. It has also been suggested that as it is silver, photography shops can help you get rid of it safely, as they send in their spent chemicals to companies that recover the silver.

 

So after the hour, I couldn’t wait any longer and took out the silver piece. 

 

 

 

This is how it looked when I first took it out. After a scrub with a scourer, I treated it with liver of sulphur to bring out the texture and sanded back lightly to reveal the pattern.

 

 

 

This attempt wasn’t deep enough to polish, when I tried it lifted all the patina off again, but I quite like it as a matt textured piece!

 

I can’t wait to try this out again and experiment, I can now do all the things I’ve tried in copper, but in Sterling silver!

 
Caroline
 

 

Caroline Dewison

Caroline Dewison is a lifelong addict of anything creative. She settled on ceramic beadmaking 3 years ago and can be found most days at the bottom of her garden playing with mud in her studio. She draws her inspiration from the natural world and wishes there were more hours in the day to explore all the ideas in her sketchbook. You can see more of her work on her blog - blueberribeads.co.uk.
  1. Reply

    I didn know you could do this , thanks Caroline

  2. Reply

    Yay! another technique to add to my must try list…I don't have ll those bits and bobs lying around like you do Caroline but I'm sure I can getmy hands on them… :0)

  3. Reply

    Nice, love the design and am now itching to experiment, but like Lesley I don't have all the gubbins!

  4. Reply

    Very cool! I have wanted to etch silver too but have been hesitant to buy another etchant, they're so messy! This actually looks like a tidier setup. It turned out beautifully! How did you cut the vinyl pattern? With just an Xacto knife? Or do you have some fancy gadget for that It looks so perfect.

    • Reply

      Thanks Keirsten! I'm the same with the etchant, I'm such a messy worker so this is perfect for me.

      I have a silhouette cameo for cutting designs, it's a great little machine, but you can do the same with an Xacto if you have the patience!

    • Reply

      well, i guess i need a silhouette cameo then! (don't have the patience thing) thanks!

  5. Reply

    Well I think it looks great! One thing I always do is have my piece face down in solution (I use strong double sided carpet tape in a piece of polystyrene to get it to float!) as the small particles that come off during the etch will fall to the bottom of your container allowing the solution to continue etching on bare metal.
    You never know, it might not make any difference at all!! But it's all good fun either way 🙂

    • Reply

      That's a great tip Ellen, thanks!

    • Reply

      No problem Caroline! It's always so interesting to see what others use to get the same/similar end results 🙂

  6. Reply

    Nice work Caroline. Ferric Nitrate works well too, you can very quickly get a deep etch with it, but you have to keep it warm. I've always been curious about silver nitrate/electrolysis method, so thanks for sharing:)

    • Reply

      Thanks Anna! I'm going to test this method with my bench supply and see what effect turning the power up has, if that doesn't work more quickly, I'll definitely have a go with the ferric nitrate!

  7. Reply

    Very interesting. Thanks for sharing!

  8. Reply

    This is awesome! Where should we look to buy silver nitrate? Is it a liquid or powder? Also, do you have a photo of the battery set up? Thanks for sharing your experiment!

  9. Reply

    Thank you for the information!!!

  10. Reply

    Hi, nice article. I use the salt water etch method. If your interested non toxic methods for etching, there are loads of free tutorials on the web about it.
    Thanks,
    Rebecca

  11. Reply

    A nice thing about electro etching with silver nitrate is that the solution lasts forever–no need to throw it out. I would suggest makeing up a larger amount and using a larger container. (Steam table inserts from restaurant supply work well.) Pass the used solution through a coffee filter and save in a plastic bottle. The stuff that you strain out is silver, so let it dry in the coffee filter and keep the silver powder for recycling. In a few years I have saved around 10 ounces of silver…more than enough to pay for the silver nitrate and the rectifier.

Leave a Comment