What have I done wrong? Annealing problem

[awrylemming]

I have been making spine beads and had a problem with the first two, I think as I used a frit base and overdid the amount. They both split directly across, horizontal to the mandrel and I hadn't annealed them.  This time I made two with silver glass, one with triton and the other Kalypso, garaged them on the usual schedule in my SC2, all fine.  I reamed them last night, and put them on top of the piano where all my new beads live. 
Five minutes ago, I was sitting at the pc, minding my own business when the triton bead, um, broke in half with a bang, sending one half flying across the room.  I've never seen the like    And I definitely didn't roll it in dynamite or anything like that, before anybody asks 
So what have I done wrong?

[helbels]

Hiya,

Were the beads encased and if so, what clear dis you use?

Some clears don't play nicely with silver glass.

Helen

[Trudi]

Hmmmm  - it could be the clear on the silver glass, but it also sounds like a thermal crack - ie they've gotton cold to quickly!

[awrylemming]

They were encased and I used CIM on both - and it was the annealing schedule given in the SC2 manual which I used - I've never had a problem before with beads breaking a day later, but I've never annealed silver glass before.  This is the first time I've ever got it to play nice, so I'm a bit sad to lose it.

[Trudi]

It doesn't sound like an annealing problem if your other beads are fine (but just for info - you can find a schedule here http://www.frit-happens.co.uk/wiki/Annealing)

As far as I'm aware, CIM glass should be fine   - my guess was that they cooled too much before going into your kiln or fibre blanket! Although another point to consider, if they were pressed beads, were they pressed too thin perhaps??

Do you have any pictures?

[awrylemming]

I shall have a go at piccys, and load them up later, thanks

[hollergrafik]

Maybe after pressing you didnt get them hot enough again or looked at them for too long (I have done this) before garaging.

[jammie]

One of mine (spine bead attempt 2 ) cracked after annealing, I thought it was because it took so long to add the clear before pressing but I didnt notice it till it came out of the kiln. It was a vertical crack.

[awrylemming]

Righty ho, this is the broken bead, excuse my photography


SDC10241 by awrylemming, on Flickr

and this is the survivor


SDC10258 by awrylemming, on Flickr

and I was really good with these two Kay, as I made that mistake with the first two, straight in the kiln   

It might, however, be the amount of time it took to get on the clear, but I can't see a way round that with a hothead.  And I used the same technique with the surviving bead.  It's more the landing on the other side of the room that surprised me. 

And I wish I could find a way to make the pictures smaller!  Aaaargh, I hate computers.

[hollergrafik]

The bead pics are a perfect size, as for the other side of the room it just 'pinged'
I am baffled, did you reheat to a glow after you pressed it, how wide is it, is the bead at least double the width of the mandrel?

[Billie]

Shame    The crack runs from hole to hole, along the mandrel line?  I get this when I don't keep my tree beads warm enough (usually when I forget to warm the back of the bead because I've been distracted by decorating the front).  Once you've encase the bead, I think you need to get it back up to glowing, then allow to cool again at the end of the flame before putting in the kiln.

[jammie]

That cracked one looks the same as mine and i,m pretty sure it was not keeping it hot enough as i was melting a thick rod of clear on a hot head and it took yonks.i thought I would encase in smaller goes rather than winding on in a thick coil.
The bottom ones pretty never had the pinging....ghosties  maybe

[MangoBeads]

That looks like a 'i got too cool' crack to me - what bad luck 

[Trudi]

That looks like a 'i got too cool' crack to me - what bad luck 

I think so too  - so you need to give it some more heat after you press it! At least you know, and cna try again. Good luck xx

[awrylemming]

Thanks everyone - I thought I had put it back in the flame for long enough but obviously not.  I even encased with stringer as it seemed slightly faster.  Next time I'll heat the bejesus out of it!