Headpins

[Patstone]

I dont normally make headpins but when I do mine dont seem to be perfectly round, is there a knack to this or is it just pot luck and filing after.

[Dennis]

I dont normally make headpins but when I do mine dont seem to be perfectly round, is there a knack to this or is it just pot luck and filing after.

Nor do I Pat, but I had a session of experimenting. I found that keeping the wire vertical was essential obviously. Using a bushy flame and withdrawing it slowly also gave a better result.

I have read here that tarnish resistant silver was ideal for this, but I cant remember which. I think it was Argentium.

You can also tap the heads flat if you thread the pin into a draw plate or a watchmakers riveting block. Regards, Dennis.

[caroleallen]

Argentium is brilliant for this Pat. Balls up like a dream.

[ajda]

Argentium is brilliant for this Pat. Balls up like a dream.

Agreed - I use 960 grade from Allied Gold, and 935 is available from Cooksons. Apart from balling up nicely for headpins, you don't get firescale and it needs minimal pickling and cleaning. You might find this link useful as a starting point - http://riograndeblog.com/2011/08/making-headpins-from-argentium-silver-wire-a-book-excerpt-from-scott-david-plumlee/

[Wallace]

I just use fine silver, no fire scale issues it either.

[caroleallen]

I use fine for pendants and earrings, but it wouldn't last a minute on a bangle.

[ajda]

Another advantage of Argentium is that you can harden it in an oven/kiln (precipitation hardening) - which at the same time improves its tarnish resistance.

[Wallace]

Another advantage of Argentium is that you can harden it in an oven/kiln (precipitation hardening) - which at the same time improves its tarnish resistance. great if you have one or the other.


I use fine for pendants and earrings, but it wouldn't last a minute on a bangle. must admit, I only do them occasionally, and for earrings, necklaces and chain bracelets to hold beads on - I use relatively thick wire, but one day will probably find it better to use something else for the bracelets.

[ajda]

great if you have one or the other.
A domestic oven is all you need (300C for 1.5-2 hours is ideal, but slightly lower for slightly longer will do it). In any case, Argentium work hardens much the same as traditional sterling. Either way it won't be as soft as fine silver.

[ps_bond]

My domestic oven tops out at 230C, but it's a time/temperature transition thing (yeah, your version was plainer English :) )
My kiln will hit 1200C, which gives all sorts of potential.

[Dennis]

As is understand it, precipitation hardening is different from work hardening in that it makes metal hard but brittle, so not ideal for thin wires. Dennis.

[Patstone]

Why cant you harden it in the normal way. I want it for the ends of earwires, just a feature, instead of making a ring, plus I want to make some more studs for me which are just a ball on a wire.

[ajda]

Why cant you harden it in the normal way. I want it for the ends of earwires, just a feature, instead of making a ring, plus I want to make some more studs for me which are just a ball on a wire.

You can harden it in the normal way. Argentium work hardens just the same as traditional sterling. All I was saying is that you can, if you want, also harden Argentium by a simple heat treatment, which can result in a greater hardness than you can achieve with traditional sterling. (But it's not compulsory.)

[Patstone]

Oh I see, always worked with sterling, and gold if I can afford to buy it. I will give it a try next time I place an order, thank you.

[ajda]

As is understand it, precipitation hardening is different from work hardening in that it makes metal hard but brittle, so not ideal for thin wires. Dennis.

Interesting - I've not heard that before. I simply assumed that precipitation hardening and work hardening would result equally in increased brittleness - plasticity decreasing in proportion to hardness increasing. But perhaps there's a difference in the internal structure of the alloy in each case? A superficial Google search doesn't reveal anything much - any suggestions as to where I could find out more about it?


Going back to the oven/kiln issue - this is part of an answer I got a while back from Peter Johns, the inventor/creator of Argentium. I had several other questions, but was asking here specifically about precipitation hardening:

a) How critical is the timing and how should it differ for items of different sizes - say, for example, a skinny earwire or a chunky ring? I've read advice ranging from 30 mins to 2 hours...

We generally recommend 300°C for two hours because in our experience most objects, no matter how large or thick, will be hardened in this time. Thin wire should harden in one hour at 300°C. It is also possible to use lower temperatures for smaller size objects. At 220°C for two hours for example, small objects should harden sufficiently (220°C being the maximum temperature in most UK domestic ovens). The hardening times quoted are time at temperature, followed by a slow cool.

b) Should this always be the last stage before final cleaning and heat-treating for tarnish resistance, or is it OK to carry out some further work on a piece - eg cutting/engraving/polishing - after precipitation hardening?

Hard metal is generally better and easier for polishing, engraving and machining. We recommend hardening Argentium 960 after the last annealing or soldering operation and before finishing. Stones can be set when Argentium silver is annealed or has been hardened. When hardened Argentium 960 is about the same hardness for setting as fourteen karat gold. Where stones have to be set that are sensitive to heat it is obviously better to harden before setting the stones.

[ps_bond]

Interesting - I've not heard that before. I simply assumed that precipitation hardening and work hardening would result equally in increased brittleness - plasticity decreasing in proportion to hardness increasing. But perhaps there's a difference in the internal structure of the alloy in each case? A superficial Google search doesn't reveal anything much - any suggestions as to where I could find out more about it?

a) You're correct, but precipitation hardening is more thorough/even than work hardening.
b) http://www.amazon.co.uk/Introduction-Precious-Metals-Mark-Grimwade/dp/1408122634 - not Argentium specifically, but a fairly good treatise on the tech side.


Hard metal is generally better and easier for polishing, engraving and machining. We recommend hardening Argentium 960 after the last annealing or soldering operation and before finishing. Stones can be set when Argentium silver is annealed or has been hardened. When hardened Argentium 960 is about the same hardness for setting as fourteen karat gold. Where stones have to be set that are sensitive to heat it is obviously better to harden before setting the stones.

"Hard" here is relative. Hardened silver is still not really a patch on hardened tool steel - it is still a very soft metal. Don't have the Brinell figures to hand at the moment.

[ajda]

Thanks for the book link, Peter - another one to add to my ever-expanding wishlist... At risk of flogging this one to death, here's a link to a short article explaining precipitation hardening in simple terms - http://argentiumguild.blogspot.co.uk/2011/07/precipitation-hardening-of-argentium.html
Alan

[Dennis]

My assumption was based on this excerpt from Ganoksin, from which I assumed that while work hardening distorted the internal structure, precipitation hardening left it crystalline.

[Stacey]

I dont normally make headpins but when I do mine dont seem to be perfectly round, is there a knack to this or is it just pot luck and filing after.

A tip I found somewhere works for me with sterling, which is when the ball first forms it will ride up the wire. Remove the heat immediately. Otherwise I will try Argentium too :-)

[medusa]

I'm weird. I like the less than perfect pins.

[Nick martin]

Argentium is brilliant for this Pat. Balls up like a dream.

Carole,

If you use Argentium for pins, do you employ the same technique you would using other silvers. I.E. suspend the wire vertically and heat with a bushy flame?

Cheers,

Nick

[caroleallen]

Yes indeed Nick.

[ajda]

A brief PS on this subject...

As is understand it, precipitation hardening is different from work hardening in that it makes metal hard but brittle, so not ideal for thin wires. Dennis.

Interesting - I've not heard that before. I simply assumed that precipitation hardening and work hardening would result equally in increased brittleness - plasticity decreasing in proportion to hardness increasing. But perhaps there's a difference in the internal structure of the alloy in each case? A superficial Google search doesn't reveal anything much - any suggestions as to where I could find out more about it?

a) You're correct, but precipitation hardening is more thorough/even than work hardening.
b) http://www.amazon.co.uk/Introduction-Precious-Metals-Mark-Grimwade/dp/1408122634 - not Argentium specifically, but a fairly good treatise on the tech side.
I've just ordered a copy of Mark Grimwade's book mentioned here - thanks for the recommendation, Peter, I looking forward to reading it. And I heard back eventually from an expert on Argentium, to whom I sent a question, to say that precipitation hardening should not result in greater brittleness than work hardening. The issue of brittleness does arise with Argentium when it is actually at high temperature, so when red hot it should not be moved or quenched or it may crack - the advice when annealing is to wait for the glow to go out of the metal before quenching.
Alan

[Nick martin]

I've been reading this thread with interest, especially as I only just noticed that Cooksons are now selling Argentium.

Personally I wouldn't quench any metal that I work with now, and much prefer placing work on a steel block to cool it down. As you say, a quick search on the internet shows that Argentium needs to be supported to prevent sag, anneals when its an orange glow colour / wet looking, and shouldm't be touched whilst hot for fear of brittleness and cracks.

Going to buy some to see what its like to work with. As it doesnt develop firescale, I presume it polishes up to a brighter finish than regular silver?

Also does anyone who regularly works with Argentium recommend a specific type of flux or solder that Cookson sells?

The only bit so far that baffles me a little, is fabricating with Argentium. With regulard sterling / fine / reflection silvers I can have a piece with many different solder joints on it no problem, as you do when making something a bit more complex.
But with Argentium does this start to become tricky or would you simply approach several solder joints in the same way? Or would you forget the solder and just concentrate the flame on each specific joint in order to fuse them?

Thanks and apologies for asking some fundamental questions, but it looks like an interesting alloy to work with.

Nick

[ps_bond]

I've just ordered a copy of Mark Grimwade's book mentioned here - thanks for the recommendation, Peter, I looking forward to reading it. And I heard back eventually from an expert on Argentium, to whom I sent a question, to say that precipitation hardening should not result in greater brittleness than work hardening. The issue of brittleness does arise with Argentium when it is actually at high temperature, so when red hot it should not be moved or quenched or it may crack - the advice when annealing is to wait for the glow to go out of the metal before quenching.


Excellent, I hope you find it as useful as I do.
The red-short issue is very real and it'll bite you if you have a piece that can sag at soldering heat - a bangle, for example.

[ajda]

I've been reading this thread with interest, especially as I only just noticed that Cooksons are now selling Argentium.

Personally I wouldn't quench any metal that I work with now, and much prefer placing work on a steel block to cool it down. As you say, a quick search on the internet shows that Argentium needs to be supported to prevent sag, anneals when its an orange glow colour / wet looking, and shouldm't be touched whilst hot for fear of brittleness and cracks.

Going to buy some to see what its like to work with. As it doesnt develop firescale, I presume it polishes up to a brighter finish than regular silver?

Also does anyone who regularly works with Argentium recommend a specific type of flux or solder that Cookson sells?

The only bit so far that baffles me a little, is fabricating with Argentium. With regulard sterling / fine / reflection silvers I can have a piece with many different solder joints on it no problem, as you do when making something a bit more complex.
But with Argentium does this start to become tricky or would you simply approach several solder joints in the same way? Or would you forget the solder and just concentrate the flame on each specific joint in order to fuse them?

Thanks and apologies for asking some fundamental questions, but it looks like an interesting alloy to work with.

Nick

Cooksons only sell the 935 grade - if you want 960 try http://www.alliedgoldltd.com/

I do quench, as I think you get a slightly softer anneal, but I'm cautious - after torching I turn all the lights out, wait for the glow to fade and I don't have any cracking problems.

Yes, you can finish Argentium (both grades) to both a harder state and brighter polish than traditional sterling. We've already talked about precipitation hardening here. Further finishing to develop maximum tarnish resistance requires careful cleaning and a longer, lower temperature heat treatment - some useful points in this discussion: http://argentium-guild-forum.2304831.n4.nabble.com/What-is-the-best-approach-to-improving-tarnish-resistance-td4383053.html

You can solder Argentium much like sterling (though the tendency to sag or crack at high temperatures may require a slightly different approach, depending on the piece) and Cooksons sell a range of Argentium solders from easy to extra hard. They also sell a flux specifically for use with Argentium, which looks and behaves like Auflux - http://www.cooksongold.com/Jewellery-Tools/Argentium-Soldering-Flux-150ml-prcode-997-6425 - I've been using both successfully for fusing, just brushing a little over the joint area itself. It seems to help the metal to flow, but because you don't get firescale you don't have to worry about shielding other parts from exposure to the flame. If you have accurate heat control with a suitable torch (I use a Smith) you can do virtually all joins by direct fusing without solder, but it takes some practice to recognise the fusing point so not over-do or under-do it. Argentium does not conduct heat as fast as sterling, so it's easier to concentrate the heat on the joint area itself.

Alan

[ajda]

Just to add a couple of points to this discussion.

First, re annealing, I had an excellent discussion on the phone recently with the inventor of Argentium, Peter Johns. It was mainly about furnace annealing 960 tubing (of which I've obtained quite a large quantity mainly for putting cores in glass and silver beads) but we ranged over other related topics. Interestingly, on the subject of torch annealing he asked how I judged temperature - and when I talked about looking for a pale red-orange glow as normally recommended with Argentium, he said you don't need to take it that hot, but to look for just the first hint of redness and then take the heat off. He reckons also that silversmiths commonly heat sterling much hotter than actually required for effective annealing.

Second, I'm now well into the book recommended by Mr Bond here - Introduction to Precious Metals: metallurgy for jewellers and silversmiths by Mark Grimwade - an excellent read for someone like me who now wishes he'd paid more attention at school in Physics and Chemistry... I did think at the time I had some deadly dull teachers, including son of Barnes-Wallace the bouncing bomb man (though I bet if I met him again now, I'd find him fascinating).

Oh, and one other thing, going back to the original topic of headpins, here are a couple of links that might be useful to someone: http://www.wiredupbeads.com/headpin_tutorial.html
http://riograndeblog.com/2011/08/making-headpins-from-argentium-silver-wire-a-book-excerpt-from-scott-david-plumlee/

Alan