Monday, March 7, 2016

My First Experiments Etching on Silver with Nitric Acid

Those of you following my work know that one of my latest projects is making saddle rings (large, boho-style rings usually with a lot of decoration).

So I'm ready to start on my silver saddle ring.  First step is selecting a graphic to etch onto the base part.

You wanna guess how long it takes to find something I want?  I'll let you know when I get there.

Are there a million patterns that would look great on this ring?  Yes.  But apparently I want something special... something with meaning (well, meaning to me, anyway).

I have to decide if this is one of those times when I'm "overthinking" it.  Perhaps.

I settle on some nouveau style graphics.  I create two patterns.  One with bolder lines; it's a bit flowery.  The other seems more my style.

I can't show you my work in progress for my first rings because I'm using a purchased template and am respecting the seller's request not to show images of it. 

But when I switch to the other template, I'll include pics.

In the meantime, if you're curious to try saddle rings for yourself, Nancy Hamilton has some free basic templates on her website.

As most of you know, I've been working for many years to perfect etching on copper.  I even have a couple of tutorials.

Etching on silver is significantly different from how I etch on copper.

For silver, I start with this.  Etching mordant from Rio.

It's a diluted nitric acid.

I haven't used ferric nitrate, but hope to compare the two some day.

While I can't show you all my images from this work in progress, I can show you the non-proprietary ones.

Here's an embellishment for one of the rings.  I decided this was a good starting point for what to etch first. 

Sorry I didn't take a pic before etching.  It would have been nice to show you how crisp and clean my transfer was.

Here's a shot right out of the etch.  Most of the paint pen (stronger than Sharpie) has disappeared (it would be the very dark black around the edges.  Some remains.


I also notice that the nail polish I used as a resist (on the sides and back) seems to have come off.  Notice the "ribbon" of nail polish in the middle of the left side.

I lost a few spots of PNP (probably the strongest resist I use).  Upper left and middle.

Here's a shot after I cleaned off the resist.



Not a clean etch at all, IMO, but it's a starting point I can work with.

Here's the same piece after cleaning it up a bit more and getting it ready to solder onto the ring.



I go to the Rio listing and read the reviews.  Everyone says this etchant works way too fast and removes the resist and must be diluted 50/50 with water.  Truth be told, I did read the reviews prior to trying it out, but I like to see for myself (hey, don't want to believe EVERYTHING you read).

So in this case, my first impression is to agree with the majority.  One caveat... I don't actually recall if the mordant I put in the little glass vial was diluted or not.  Sigh (this is what comes from having months in between my experiments).

Since my etchant does seem too strong anyway, though, I go ahead and dilute it 50/50 with water (yes, adding the acid to the water).

As before, I go out every ten minutes and wipe off any crud that may adhere to the piece.  I'm not using an oscillator/vibrator or any sort... it's just floating in a bowl.  It is upside-down, but still.

So after 30 minutes, I run a fingernail along the top of the second piece and it feels bumpy.  So I pull it out and remove the resist, only to see not a darn thing happened.  Ha!  There was ZERO etch.

Stopped work in order to have breakfast... going back now to start from scratch.

I decide to take this ring blank and roll it through the mill just for variety.



Then I take new etchant and dilute it so I know exactly what I'm working this this time.  Luckily, I don't have to prepare another piece... I already have two more waiting in the wings.

I'll shoot for 60 minutes this time.

And by the way, when I'm done with this etchant, I'll probably switch to ferric nitrate.  I'm not comfortable with any of these, but I would like to etch silver once in awhile.

I check at 60 minutes and we have nothing that I can discern.

I check at 2 hours and 15 minutes and really still see nothing.  Getting a bit frustrated at this point.

Added a bit more acid to my diluted mixture.

It's possible I'm having a slow reaction due to the temperature.  Since I don't have an official venting system, I have the etchant outside.  According to weather.com, it's 58 degrees outside at the moment.  The etchant works best between 70-80 degrees.

At the 3 hour mark, I added more acid to the mix and ordered ferric nitrate.  (Mind you, I'm not really blaming the nitric acid... it's just that I've had time to research a little and I just want to try the third method so I have a good basis for comparison.)

At 3 hours and 40 minutes, my resist started coming off so I removed the piece.  There appears to be an etch, but not deep.  Not what I'm used to with copper (with copper I can achieve a deep etch in under five minutes).

I cleaned the piece and annealed it ready for bending into ring shape so I can solder the shank join.

Then I annealed the rolled shank, readying it for soldering.

My third piece is back in the etchant.  It's been over an hour now.  I've gone out and cleaned it off gently twice.

I admit to getting a little bored of babysitting the etching process, but if I get something useful, that'll be good.  No soldering today.  It's already three, which won't seem late to most people but if my day starts at five or six in the morning, I start to fade in the afternoon.  I do feel like someone who's put in nine-hour day... because I have.  I won't necessarily stop WORKING; I just won't do anything that requires precision.  :-)

So the final piece was in the etchant for about 90 minutes.  There was a total of about 1.5 ounces of mordant and .5 ounce of water by the time I was done.

Here are parts of the etches.


I have some errands to run tomorrow (and it's SRAJD application processing day).  But I hope to get back to working on these rings this week for sure.

3-21-16: Update... here are the two finished rings from the etching that day.



Thanks for tuning in! 

7 comments:

  1. Hi Laura ... I found this post very interesting. I've been curious about acid etching silver for a long time. I did it with copper in school. But never silver.

    What I have done many times is etch silver with an electronic etching system. I find it works very well for me. I bought it because I didn't want to worry about proper disposal of the used etching acid. I get a pretty deep etch after 20 - 30 minutes or so ...

    It looks like you have a very visible etch on the third go round. Looks great!

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    1. Hi Bob. Thanks for posting! My first time etching on silver with with silver nitrate and electricity. I wonder if that's similar to what you describe. I have a heck of a time with the aluminum connectors but should try again some day (not that I got heavier gauge aluminum wire).

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  2. I tried the nitric acid in a class and used paint pen for resist. It went so fast it blew the paint pen off so I took it out, rinsed it and reapplied paint pen. Etched it again, began to lose the paint pen, took it out and scrubbed. Not very deep but the etch was multi level, which was so of interesting (I didn't quite get the same area covered the second time.
    Ferric nitrate worked more like ferric chloride, took about the same time and the PnP stayed on. The problem is it didn't last more than a couple of weeks and then it was dead.

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    2. Thanks for sharing your experiences! I'm looking forward to trying ferric nitrate.

      The multi-layer etching sounds kind of cool, too.

      Sometimes when we experiment, things may not go as planned but it doesn't necessarily mean we don't end up with something great. :-)

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  3. This is interesting Laura...thanks for sharing your process. I'm still working on perfecting the copper etch and your tutorials are VERY helpful...I like to work outside with that so at least another two months for that:)

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    1. I hope you keep me posted to your progress and results. Etching is definitely cool in that in can add an element to design that may be hard to achieve otherwise, but I don't think it's something I'd want to do on too regular a basis. But who knows? I've learned never to say never. :-)

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