Cutting a recess in sheet silver

[Kathryn Harrison]

I've been toying with a design where I want a recess in the silver and I'm not sure the best way to go about it. It doesn't need to be deep (.2-.4mm maybe) but over a largish area 5x20mm. I was wondering if the easiest/best way would be with chisels or using a dremel to cut it away?

[trialuser]

I have etched something similar in the past, but probably not that deep, would that work?

[Dennis]

The simplest way undoubtedly is to sweat a second sheet over the top, with the hole already cut with a saw. When sweat soldering a tiny bevel at the lower edge helps to hold the solder from escaping.

Another way is to use a flat scorper inside a scribed area, but the floor will be textured

[Goldsmith]

I would suggest that you learn how to cut with scorpers, like enamellers do when cutting recesses for enamel work. Take a look at this short video showing Jane Short making an enamel brooch, it does show Jane using scorpers when cutting recesses for enamels;
https://www.youtube.com/watch?v=AV0fej_sU10

James

[Kathryn Harrison]

Thanks everyone! I don't have etching capabilites at the moment but it is tempting!

I'm torn between the flat scorper method and sweat soldering both would work in terms of finish I've tried soldering two flat largish surfaces together so each is a learning curve :)

[Wallace]

salt water (electro /green etching) is relatively easy to set up. Works with both silver and copper really well.

http://www.inbarbareket.info/blog/2011/04/17/green-electro-etching/

[Kathryn Harrison]

salt water (electro /green etching) is relatively easy to set up. Works with both silver and copper really well.

http://www.inbarbareket.info/blog/2011/04/17/green-electro-etching/
Wow I had no idea that worked on silver as well as copper! Ooo that's tempting indeed.

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[Didi]

Hi Kathryn, if you have a rolling mill you can run the sheet through it with a piece of paper the size of the depression you want placed on top. The paper will form a depression in the silver. I made a belt buckle using this technique.
7799

Didi

[Ralph G]

Sweat soldering would be the easiest and fastest esp since its a simple rectangular recess.

But from me another vote for etching. :)
From my experience Saltwater as electrolyte does NOT work. From a chemical point of view that makes sense because salt (NaCL) has Chlorides and produces a crust of insoluble Silverchloride on the piece that prevents further etching. Same reason Ferric chloride does not work on silver . After a minimal etch Silverchloride is formed and etching stops. You need to form a soluble silver salt.

I have tried many things and would recommend either ferric nitrate or electro-etching with diluted 3% Nitric or 10% Silvernitrate solution for etching Fine silver or sterling.
0,4mm is quite doable. especially if there are no intricate details. Electroetching with 3%Nitric or AgNO3 has the advantage that the electrolyte can be reused many times because it does not saturate. Dissolved Silver is constantly deposited as 999 Fine silver at the Cathode and can be easily reclaimed, just filter it out, wash, collect some, and remelt.
You only need low voltage so it could be done with a battery(takes a bit longer than a Power supply because less amps). But fine detail is also quite possible.780578067807

[ps_bond]

But from me another vote for etching. :)
From my experience Saltwater as electrolyte does NOT work. From a chemical point of view that makes sense because salt (NaCL) has Chlorides and produces a crust of insoluble Silverchloride on the piece that prevents further etching. Same reason Ferric chloride does not work on silver . After a minimal etch Silverchloride is formed and etching stops. You need to form a soluble silver salt.

I would agree - and yet there are still many people who would advocate saltwater etching regardless of the chloride solubility issue.
A reminder that nitric acid now needs a licence for private individuals to purchase - and later on to possess (stupid system...).

[ps_bond]

But from me another vote for etching. :)
From my experience Saltwater as electrolyte does NOT work. From a chemical point of view that makes sense because salt (NaCL) has Chlorides and produces a crust of insoluble Silverchloride on the piece that prevents further etching. Same reason Ferric chloride does not work on silver . After a minimal etch Silverchloride is formed and etching stops. You need to form a soluble silver salt.

I would agree - and yet there are still many people who would advocate saltwater etching regardless of the chloride solubility issue.
A reminder that nitric acid now needs a licence for private individuals to purchase - and later on to possess (stupid system...).

BTW - I'd carve it out, whether hand pushed or powered.

[Ralph G]

People think etching with salt is "green" and non toxic because we handle it every day but one thing not to forget when etching with saltwater is that at the cathode chlorine gas (toxic) is released. With small pieces and short etch times admittedly not a very big problem but on larger pieces and deep etches it could well be.

Fortunately I am from germany and we can still get nitric without license but this will change at 1.3.2016 when new EU- regulations are made. Can you still get Silvernitrate? This works as well but initial costs are higher because its more expensive. With 1L of 10% silvernitrate electrolyte you can "dissolve" about 800g of sterling without problems - that would translate to a fair number of etched pieces mitigating the initial price tag.

As for alternatives to something that is easily avaliable off the shelf and works good I have found no viable alternative so far. Most silver salts are insoluble and thus dont work. The only soluble ones are

Silveracetate , about 10g/L
Silversulfate about 8g/L
and
Silvernitrate about 2130g/L

the difference is quite obvious...

PS: tried vinegar as well and got a little deeper etch than with salt but soon stopped also, faint etch yes, a good one no., also household vinegar has some chlorides (its not made with distilled water) and the silverchloride issue soon arises. Maybe chloride free analytical grade acetic acid (diluted) would work better - but this I haven`t tested.

[Wallace]

It is green, due to the puce green it turns after etching. Just for the curious. It can work, just, as with all etching processes, be careful.

Most things to etch, solder, polish, piercie, hammer, file... are a risk through dust, fumes, injury, and cannot be understated. Wearing of safety equipment is very important.

[trialuser]

It's not even purchase, the offence is to acquire, so you can't be given some or similar.
You don't need an EPP licence (https://www.gov.uk/government/publications/licensing-for-home-users-of-explosives-precursors/licensing-for-home-users-of-explosive-precursors#fees) for nitric acid if it is not over 3%, I've no idea if you can buy it that 'weak' though.
The licence cost £39.50 for 3 years, easy to get assuming you've not been too naughty in the past, all done online, you just have to jump through a few hoops. I need one for my other hobby where I use oxidisers and Barium salts (amateur pyrotechnics).
If you are a business the licence is not required.

[ps_bond]

It's not even purchase, the offence is to acquire, so you can't be given some or similar.

Sorry, yes - similar to the catch-all on offensive weapons (purchase, hire, lent et al) but soon to include possess as well.


You don't need an EPP licence (https://www.gov.uk/government/publications/licensing-for-home-users-of-explosives-precursors/licensing-for-home-users-of-explosive-precursors#fees) for nitric acid if it is not over 3%, I've no idea if you can buy it that 'weak' though.
The licence cost £39.50 for 3 years, easy to get assuming you've not been too naughty in the past, all done online, you just have to jump through a few hoops. I need one for my other hobby where I use oxidisers and Barium salts (amateur pyrotechnics).

I wholeheartedly disapprove of such hoops. They're only ever used as a stepping stone to further restrict things (and add people to watch lists) and act as no deterrent to those with deliberately nefarious purposes.


If you are a business the licence is not required.

Exactly. Which is where the whole thing becomes a bit silly...

Anyway, I'm drifting into politics and completely OT. The "green" nature of chemicals is always amusing; citric acid pickle may be fairly harmless, but as I've said in the past once it has copper salts dissolved in it it becomes much more toxic.

[Ralph G]

UK laws seem to be much stronger than over here - but that will also change soon... Restrictions for the purchase of even fairly innocuous other substances are getting more and more silly. Seem like if you are doing something with "chemicals" its now immediately associated with being a potential terrorist...

Yes, it seems 3% is still legal in the UK, thats all you need and works perfectly fine plus much cheaper than silvernitrate. I prefer it over ferric because lasts longer & the silver is recoverable.

apcpure.com/product/nitric_acid_3

[Kathryn Harrison]

I think like you say it is easy to be wary of only chemicals you don't normally have in the home and people really misunderstand the whole idea of chemicals and reactions. The salt option just seemed easier to achieve than getting hold of and storing acid.

With the 3% nitric acid would it need further dilution. What safety precautions would you take?

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[Goldsmith]

Kathryn, your original question was about achieving a 5mm x 20mm shallow recess, can you show a design of what you hope to achieve. A while back someone asked about cutting a recess for enamel in a butterfly shaped pendant. I suggested cutting with scorpers and I cut this test piece in a sheet of copper to show what I meant. This piece took me half an hour to draw pierce and cut the recess.

7809

James

[Ralph G]

Kathryn,
I dilute just to 3% this works good. Lower % than that I have not tested . Its still an acid ,so should be treated with respect. I have compared the MSDS sheets for both 65% and 3% Nitric (cant post links yet, sorry.) and while 65% is dangerous, severe acid burns eye damage etc the 3% is listed only as being an "irritant". Still - wear gloves and dont get it in the eye etc etc . But compared to full strength its much less agressive. The used solution should be stored in a dark bottle or away from sunlight for the next use because silvernitrate (which will develop in the solution) is light sensitive.

If you etch sterling the solution will turn blueish over time thats because of the copper content. But thats no problem, quite the opposite- a certain level of copper faciliates the forming of nice glittering silver crystals at the kathode instead of a sponge-like deposit. Up to a level of app. 60g/L of copper, the silver is deposited as 999 pure , with more copper in it it will begin to co-deposit. Hence the "800g" limit I mentioned above. It will work beyond that but you wont get 999 pure anymore.

[Kathryn Harrison]

Kathryn, your original question was about achieving a 5mm x 20mm shallow recess, can you show a design of what you hope to achieve. A while back someone asked about cutting a recess for enamel in a butterfly shaped pendant. I suggested cutting with scorpers and I cut this test piece in a sheet of copper to show what I meant. This piece took me half an hour to draw pierce and cut the recess.

7809

James
I'm hoping that my teacher has a scorper I can try tomorrow night to see if I have any talent for this. Immediately I think it might be a good option that or sweat soldering but I have also wanted to try etching so I got a little side-lined with the prospect!

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[EllaK]

It's not even purchase, the offence is to acquire, so you can't be given some or similar.
You don't need an EPP licence for nitric acid if it is not over 3%, I've no idea if you can buy it that 'weak' though.
The licence cost £39.50 for 3 years, easy to get assuming you've not been too naughty in the past, all done online, you just have to jump through a few hoops. I need one for my other hobby where I use oxidisers and Barium salts (amateur pyrotechnics).
If you are a business the licence is not required.
Hi. I’m a lapsed jeweller, I haven’t made anything for a while but still have most of the kit, including an almost full 3 litre bottle of nitric acid (59%). I don’t envision wanting to use it again, and looking at this thread it seems that I should be rid of it sooner rather than later. Does anyone have any advice on what I can do?