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by george
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Author Topic: Silver tubing for big-hole bead cores  (Read 1872 times)
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ajda
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« on: June 25, 2015, 09:11:23 AM »

This is for anyone out there who puts solid silver cores into big-hole beads using one or other of the bead-liner tools.

I generally use sterling silver tubing from Ginko Designs on Etsy. In all my other silverworking I use a slightly different alloy - Argentium 960 - including for the bead caps that I make and I'd really like to use this for the cores as well. I prefer it to sterling for its working properties, its higher purity and its anti-tarnish properties.

I have been been looking into getting a supply of tubing in Argentium 960, but to get it done to my exact specifications I'd have to commit myself to a minimum order worth around 900. I core a lot of beads, but that probably represents 2-3 years supply and I can ill afford to tie up so much money in stock.

So I am wondering whether - assuming quality is good and prices reasonable - anyone would be interested in buying smaller quantities from me, thereby helping me spread the cost?
« Last Edit: June 27, 2015, 06:23:14 AM by ajda » Logged

ajda
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« Reply #1 on: June 27, 2015, 06:22:20 AM »

Just to add, for those who are most familiar with the traditional sterling standard and may be unsure of a silver alloy that goes by a different name, Argentium 960 can legitimately be labelled Sterling Silver.

I have checked, via the Cookson Gold forum, with an expert at the London assay office. Any alloy with a minimum silver content of 92.5% qualifies as sterling. Argentium comes in two grades: 935 (93.5% silver) and 960 (96% silver). If hallmarked, the former would be stamped 925 (minimum fineness for sterling standard) and the latter would normally be stamped 958 (minimum fineness for britannia standard), but both can correctly be described as sterling and both could, if you chose, be stamped 925, meaning simply at least 92.5%.

If you want to know more about Argentium, see http://www.argentiumsilver.com/
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marijane
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« Reply #2 on: June 28, 2015, 04:15:53 PM »

What is Argentium like to work with in terms of work hardening? What dimension were you thinking of? 
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ajda
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« Reply #3 on: June 28, 2015, 07:58:23 PM »

Most users reckon Argentium is a bit more malleable/ductile than traditional sterling and it can be worked a little longer and a little more aggressively between annealings. And that is how it seems to me, but I have read at least one conflicting report, so cannot be 100% sure.

My hope with the tubing is that, if it is a bit more malleable, there would be less risk of cracking or splitting when flaring a core - a problem I occasionally have with traditional sterling - though until I've actually tested the tubing in practice myself and compared it to what I am used to, I'll have to reserve judgement. I plan to get it supplied fully annealed (soft condition), so that I (and potentially other users) wouldn't have to be concerned with annealing.

If it's hardness you want in a finished piece, one of the great things about Argentium is that you can heat treat it (precipitation hardening) simply by cooking it for a couple of hours at 300C - this will get it to a finished hardness greater than you can achieve with traditional sterling, so it's both more durable and can be polished up to a higher shine. I've done that successfully on pieces of silver with glass beads. Heat treatment also increases the tarnish resistance.

I haven't worked out the ideal dimensions yet. The sterling silver tubing I get from Ginko Designs on Etsy is identical to the fine silver tubing I get from Rio Grande:
Inside dimension: 4.37mm (.172")
Wall thickness: 0.38mm (.015")
Outside dimension: 5.08mm (.200")

This works well for me using the RetroGlassTools.com bead liner, but I've found other sizes within a certain range quite OK...

What would you reckon to be ideal dimensions?
« Last Edit: July 06, 2015, 07:22:55 AM by ajda » Logged

marijane
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« Reply #4 on: June 28, 2015, 10:48:48 PM »

mmm, I'm not sure.  I would be interested, but at the moment I am just a hobbyist and if your dimensions are suitable I would only take a small amount. 
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ajda
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« Reply #5 on: June 28, 2015, 11:13:29 PM »

No problem. It doesn't matter how small your requirements - if I do go ahead with ordering a large quantity and selling it on in smaller units, I'd probably reckon on 300mm lengths as standard, but no reason why I couldn't do shorter than that. In any case, I'm hoping to get hold of some samples to check it out out myself before committing to a bigger investment - and I'll test it out thoroughly before offering or recommending to anyone else.
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theflyingbedstead
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« Reply #6 on: June 29, 2015, 08:54:51 AM »

Hi Alan,

I'd be interested in finding out more, so please add me to your list! I have a mango beadliner so I use the thin-walled 5mm tubing from Rashbel and also the 4.78mm from Rio Grande.

Charlotte
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Charlotte x
marijane
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« Reply #7 on: July 01, 2015, 02:59:00 PM »

Great.  I'll keep a watch out for news.
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ajda
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« Reply #8 on: August 30, 2015, 12:55:59 PM »

UPDATE - Argentium silver tubing coming soon!

Ginko Designs (Debbi Hackeson) on Etsy, who's been my main supplier for several years, has now ceased trading - which has prompted me to take the plunge and order over 1000 worth of Argentium 960 tubing... gulp! Unfortunately it worked out slightly more expensive than I first reckoned, since the original quote was mistakenly calculated on their prices for 5kg+ and I only wanted 1kg (minimum order size).

I expect to have it within a couple of weeks, then I'll test it out to satisfy myself that it works at least as well as traditional sterling for coring beads. Assuming all is well, I'll then be offering it for sale. I will list it on my Etsy shop, marking the price up a little so I cover my costs properly and make a small profit to put towards future purchases. But I will also offer it here at a discounted price for a limited time. So, if you are interested watch this space - though I'll announce it properly in the section for selling supplies etc. And if in the meantime you have any questions please pm me or post here. I can't put an exact price on it until I actually receive it because I had to order by weight and cannot work out exactly how that will translate into length (and I'll be selling it by length). I hope it won't be more than about 20 per 12 inch/ 300mm.

Specifications:
Outer diameter = 5.05 to 5.10 mm
Inner diameter = 4.35 to 4.40 mm
Wall thickness = 0.35 mm (+/ 0.025 mm)
Temper = soft/annealed
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Mars
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« Reply #9 on: August 31, 2015, 02:55:39 PM »

Total newbie here, thought I'd better explain before continuing Smiley

I want to start coring my big hole beads, but haven't got this far yet, so I might be interested too... if I can figure out what I'm doing Smiley

Mars
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ajda
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« Reply #10 on: August 31, 2015, 04:24:41 PM »

Hi Mars

Our resident expert on bead-coring gadgets is Charlotte - FHF username: theflyingbedstead. She did a series of reviews a while back which is an excellent place to start if you are looking into the subject - http://www.frit-happens.co.uk/forum/index.php?board=104.0 - scroll down to a series of 5 posts with similar titles, "Silver cored beads using..."

I'm an expert on one model only, the Retro Glass Tools one, and I added a few tips of my own in a reply to Charlotte's review. I'd be happy to expand on that if you want and to offer advice, but I can't speak for the other models.
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Quirky Bird
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Bead release me, let me glow


« Reply #11 on: September 01, 2015, 09:41:54 AM »

I'd be interested in tubing to line 5mm BHBs please.

Abby
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A clean house is the sign of a broken oxycon.
Mars
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« Reply #12 on: September 16, 2015, 10:20:59 PM »

Hi Mars

Our resident expert on bead-coring gadgets is Charlotte - FHF username: theflyingbedstead. She did a series of reviews a while back which is an excellent place to start if you are looking into the subject - http://www.frit-happens.co.uk/forum/index.php?board=104.0 - scroll down to a series of 5 posts with similar titles, "Silver cored beads using..."

I'm an expert on one model only, the Retro Glass Tools one, and I added a few tips of my own in a reply to Charlotte's review. I'd be happy to expand on that if you want and to offer advice, but I can't speak for the other models.

Thanks for this, have only just seen the message as not quite used to the forum yet Smiley  Will bookmark for a long read!
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ajda
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« Reply #13 on: September 18, 2015, 09:58:00 AM »

Well, my scarily large order has just arrived - took a bit longer than expected, plus I'm a bit preoccupied at the moment so it may be a little while before I'm able test it out to my satisfaction... I'll post again as soon as I have.
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ajda
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« Reply #14 on: September 27, 2015, 02:16:16 PM »

I'm now in a position to offer this tubing for sale and have worked out a deal for anyone who might want to buy a little on a low-risk trial basis before deciding whether they want any more of it. I hope also to be able to offer some smaller diameter tubing too, but not just yet. I'll do a post shortly in the right area of the forum for selling stuff and add a link to it here. Further details and options will appear there. Here are some pics of a few beads, glass and silver, that I fitted with cores yesterday. The coring process is easier and the results better than I have been used to with traditional sterling tubing. Below the pics is some background in case you are interested.



...and some slightly better quality close-ups of the two capped beads:



The tubing arrived not in annealed/soft condition as requested but hard. The supplier offered to take it back at their own expense to anneal it all for me in their conveyors, but having been working with Argentium 960 for some time now and having experimented a little with this tubing I decided I'd rather do it myself. I could see an advantage in being able to control the process and figure out how achieve the ideal temper myself (more on that below). But I had some questions on the technical side that I wanted advice on.

After a couple of rather unsatisfactory conversations with someone who seemed to know less than I do about it, I got a call from a "technical expert" and found myself talking to a rock-star in the fields of metallurgy and jewellery, Professor Peter Johns of Middlesex University, none other than the inventor of Argentium himself (this is him if you are curious: https://www.youtube.com/watch?v=ZLf318FYlhY). We spent over an hour talking about the tubing and discussing more widely the properties of both Argentium grades, 935 and 960. Despite feeling a little star-struck, I'm now confident in what I am doing, and I still have the option of returning some or all of it to the supplier if I have any unexpected problems.

For glassworkers used to annealing glass, the annealing of metals may need some explanation - there are similarities, but also important differences. Glass which has been at high temperatures and then cooled rapidly and/or unevenly has stresses locked into its internal structure which may cause it to fracture. Holding it at the right temperature for long enough followed by slow cooling allows these stresses to "relax" out and for no new stresses to be introduced during cooling. In the case of metals in their annealed state, the internal structure is similarly "ordered", while unannealed can be considered "disordered" - the atoms are arranged chaotically and cannot move as freely within the structure, so any force applied to the material will lead to resistance and fracture rather than yielding, stretching, bending. The exact methods for annealing different metals and metal alloys vary, but I'm just focusing on these alloys: traditional sterling (92.5% silver, plus copper) and Argentium (93.5% or 96% silver, plus copper and germanium).

Annealing these requires bringing them up to a high temperature,  then cooling rapidly (often by quenching in cold water) which, as it were, "freezes" it in its ordered state. Most jewellers use a gas torch but it can also be done in a kiln. Argentium and traditional sterling behave a little differently, so methods differ slightly, but I won't go into the details here. In the annealed state, the alloys are soft/malleable/ductile so can be worked easily, but the action of bending, twisting, stretching, hammering, etc, distorts and disorders the internal structure making it harder and more brittle. This is known as "work hardening". With a complex piece, you may need to re-anneal many times between operations so it remains workable and does not fracture. But once finished you ideally want it to be as hard as possible, since a harder metal will take a higher polish and will better resist scratching and deforming. Hardening also occurs naturally over a long period of time at room temperature or more rapidly at higher temperatures within a specific range - this is known as "precipitation hardening" or "age hardening". For most jewellery, work hardening is adequate for finishing and various techniques may be used in addition to the work of forming it - a thin earwire or earring post, for example, can be twisted back and forth, hammered on a rubber block or tumbled with steel shot to make it harder without changing its final shape. One advantage of Argentium over traditional sterling is that it is very easy to precipitation harden in a kiln, or even a domestic oven, the end result being more thorough and more even than work hardening. (This can also be done with traditional sterling, but the process is more problematic and requires equipment beyond the reach of most small-scale jewellery makers.)

In its fully annealed state, the Argentium 960 tubing is very soft and flares very easily using a bead corer, but I find it works best for me in a slightly harder state - perhaps somewhere in the region of quarter hard, where it is soft enough to flare the ends freely without risk of deforming the tube along its length. It is more flexible than traditional sterling, though the action of flaring the ends will work harden it in a similar way. For most people this will be enough for finishing cores to a high standard, but there are two additional actions that can be carried out to finish the Argentium cores to a significantly higher standard than can be achieved with traditional sterling. The first is precipitation hardening, as outlined above. The second is a lower temperature heat treatment to enhance tarnish resistance - so the cores will remain brighter and require less frequent cleaning than traditional sterling. Both these processes are easy if you have access to a domestic oven, or better still a kiln - and I can give detailed instructions and explanations for anyone who's interested.

Further info on Argentium is scattered about on the internet - I can give a list of useful links if anyone wants.
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