Splitting silver cores - Impress beadliner - help please!

[silverlemon]

Annealing silver is not quite the same as glass. With glass you're cooling the whole thing down at the same rate so that you don't have stress between all the layers as they would cool at different rates.

Annealing silver is still about removing stress and can be done in a kiln but doesn't need to be be because it is very quick and doesn't need slow cooling. We're heating the silver to make the crystals grow again so that the metal is malleable. After lots of work hardening the silver gets harder to move as the crystals get stuck up against the grain boundaries and can't fill any of the gaps between the crystals.........then we have to anneal again, unless we're ready to polish.

Going back to the split problem, it could be under under annealed, but I can't see it myself as I've successfully cored without annealing with this tool. The state of the silver in your tubes does also look to me like they've been overheated.

[julieHB]

I agree with Sarah, it could be that you are overheating the silver. It then starts to crystallize, and you can introduce brittleness (is that a word??) instead of softening the metal. Another possibility is that you chuck it into cold water too early. It should be below 500 deg C before giving it the cold shock. Quenching from higher temps "can cause distortion and even cracking" as it says in the sterling silver data sheet from Cooksons and Argex. I have tried to make silver cores manually a couple of times and what happened to me is exactly like those pics (except that you have gorgeous beads inside the cores..).  Do you have a jewellers saw? Then it's easy to remove the cores. If not, I'd be happy to do it if you send them to me..   No, I promise, I'd send the beads back.....after some time, anyway  

There's been a couple of posts since I started writing (yep, I know, I'm a bit slow) - you can anneal silver in a kiln, and, in my opinion, it's probably a lot more controlled, but if you are doing one tiny bit of metal it is not time nor cost efficient. If you do a big bit of metal or a whole lot of cores it would make it worthwhile.

[Lush!]

Oh yes, I think you've got it!

Thanks Sarah and Jaq!

I did notice an odd look to the surface once or twice and did wonder about overheating.  

Sarah, I tried a few a week or two ago without annealing and the trouble with them is that I can't get the edge of the flare to really come down onto the bead, so they're all a bit loose.

This is another question I've been wanting to ask actually - is it acceptable for the core to turn in the bead, or should it be tight?

OH BLIMEY - 2 MORE REPLIES! 

[TiaraHelen]

Thanks for your helpful answers!

[beads-on-toast]

i don't usually have that much silver spare on each side, i found they split when i had too much...

[Lush!]

So could you anneal a whole length of tube in a kiln then?  I'm thinking this could help me out here, I hate it when I'm not entirely sure what I'm doing.

I got some tube today from an etsy seller and she says its pre-annealed - I was a bit unsure about this and thought I'd anneal it again anyway but maybe I don't need to then?

[Lush!]

Too much silver?  AAAGH!!

I need more rules!

I think the Impress instructions suggest cutting tube between 3.6mm and 4.2mm longer than the width of the bead - I tend to aim for the longer amount, just cos I thought it would be better.   

[silverlemon]

I know, isn't it hard to get them tight when you don't anneal!

Although it's harder to bash the edge down with a rawhide mallet, it can be done, eventually, well after 5 minutes, and you don't get all the dents that need filing out and polishing that you do when I do it totally by hand.

[Lush!]

I've been bashing the edges of the unanealled ones with a rawhide mallet for a week and they still won't tighten!

Hmmmm ... could I put these on a batch anneal schedule in the kiln, then bash em some more?

[beads-on-toast]

i would try the shorter amount

[saffie]

i measure my bead width and add 3mm for the tube!

[julieHB]

So could you anneal a whole length of tube in a kiln then?  I'm thinking this could help me out here, I hate it when I'm not entirely sure what I'm doing.

I got some tube today from an etsy seller and she says its pre-annealed - I was a bit unsure about this and thought I'd anneal it again anyway but maybe I don't need to then?

The problem with annealing the whole rod is that when you cut it afterwards (I assume you use a tube cutter) you harden the silver again, just where you want it soft! Sorry!

[Lush!]

Darn 

[silverlemon]

Ha ha, I was thinking that too.

[julieHB]

Please, go ahead and try - I speak only of what I have researched, I have not experimented myself!!