Large beads breaking - advice anyone please?

[TheJanie]

I'm feeling really frustrated... 

I've recently started playing with making larger beads and I'm having a problem with them.

I've made five largish beads, three have survived, two have broken at different stages.  I'm not sure if it's to do with the combinations of glass in the beads, how I cool them, or my batch annealing program (or any combination of the three!).

I batch anneal my beads after letting them cool in vermiculite (I know this is a bit of a risk with larger beads) - I program my kiln following this wonderfully helpful tutorial from Helen: http://www.frit-happens.co.uk/forum/index.php?topic=859.0

These are the three that survived:


Ink Blue with a Periwinkle stripe. About 2cm long.


(Four shots of one bead) Ivory with Intense Black. About 3.5cm long.


(Three shots of one bead) Ivory with Intense Black, Coral and Turquoise. About 3.5cm long

These are the two that broke:


(Three shots of one bead) Dark Ivory base with Intense Black and Reichenbach Iris Orange.  About 3.5cm long.
This one broke as I was taking it off the mandrel.


(Three shots of one bead) Dark Ivory base with Intense Black and Reichenbach Iris Orange.  About 4cm long.
This one survived removal from mandrel and annealing but broke when I was cleaning it.

I wouldn't feel half so annoyed if the last one hadn't got all the way to the cleaning process before finally breaking!  I was so pleased and excited that I'd finally made some beads I really, really liked... I know it's something I'm doing wrong but there are so many variables...

Any advice would be gratefully received.  I've only just got my bead "thing" back after weeks of rubbish and so I'm feeling more than a little frustrated and dispirited - just as I was finally beginning to feel like a proper beadmaker

Thanks in advance...

[beads-on-toast]

iris orange might be a different COE

when i tried to encase it it cracked for me, it even cracks for Sarah Hornik

you can usually get away with 5% of the total bead, maybe batch annealing isn't helping

HTH

[Les]

When it comes to cracking, the usual rule of thumb is that if it is a clean break, then it's down to thermal shock, ie: Cooling too fast.... and if it is a kind of crazy paving crack, usually between two colours, then it's an incompatability crack....

I'm not sure what the nature of your cracks are ( oops, that sounds rude !!!!) ??

HTH ??

Les xx

[Billie]

I'd echo what Anna and Les have said.

Apart from...

I'm not sure what the nature of your cracks are ( oops, that sounds rude !!!!) ??

because that sounds smutty

[TheJanie]

Thanks for all your help with this, guys - much appreciated!

iris orange might be a different COE

when i tried to encase it it cracked for me, it even cracks for Sarah Hornik

you can usually get away with 5% of the total bead, maybe batch annealing isn't helping

HTH

Yes, I wondered that - it's a rod I bought from Tuffnell and is marked as COE 104... I've used it fairly heavily in smaller beads but if it cracks for both you and SH, then I still suspect an incompatibility and that I was just lucky!

When it comes to cracking, the usual rule of thumb is that if it is a clean break, then it's down to thermal shock, ie: Cooling too fast.... and if it is a kind of crazy paving crack, usually between two colours, then it's an incompatability crack....

I'm not sure what the nature of your cracks are ( oops, that sounds rude !!!!) ??

HTH ??

Les xx

Oo-er!    I never thought to include pics of my cracks.... just cobbled these together:

This is the one that broke when coming off the mandrel...


And this is the one that broke during cleaning...


The edges look fairly straight to me and not along the colour boundaries, so maybe it's to do with cooling after all?  The pieces fit back together cleanly...



... didn't do the first one - not brainy enough to attempt jigsaws with more than two pieces

Looking at the pictures again, the first one does seem to have far more Iris Orange on it than the second - maybe that one broke because of incompatibility and the second one because I only batch anneal?

Which would be a pity... I'm really not sure about putting beads straight into the kiln yet... no idea where to start with that one (more to do with my ME-addled brain than anything else!).  I don't know how long it would have taken me to get around to even batch annealing if it hadn't been for Helen's fab cut-out-and-keep guide!

Thanks again for your help. I'll play for a while with colours other than Iris Orange... pity... I liked those beads

[turnedlight]

What sort of kiln do you have, because I would put it on and then start bunging them in as you go, easy for me to say as that's all I've done from the start and it's hard to change but I think I would be worth it.

[TheJanie]

What sort of kiln do you have, because I would put it on and then start bunging them in as you go, easy for me to say as that's all I've done from the start and it's hard to change but I think I would be worth it.

I have an SC-2; I'm a bit nervous about annealing as I go along tbh - it's got a lot to do with my energy levels.  At the moment I have limited energy so I do two or three torch sessions a day ranging from 30 mins - 1 hr which is why I batch anneal - seems more "worth" firing up the kiln for more beads.

Mind you, I suppose if I felt I was having a good day, I could make a few large beads in a longer session and still batch anneal the smaller beads from shorter sessions...

[afina]

Hi! There is an Iris Orange 104 now, so that should not be the problem. From the pictures I would think thermal shock. With barrel beads it could be that you didn't heat them evenly, that one side got cooler than the other.

[jaz]

The only problems I have had with beads cracking is when I make longer beads (as these are) and it is because I don't keep the whole bead warm enough. I tend to concentrate on one end and forget to keep warming up the other end. Big, short fat beads are fine and it is just the long ones that cause me problems.

Helen

[TheJanie]

Thanks for the help, all

I've made some more which appear to have survived the cooling, removal from mandrel, batch annealing and cleaning - yay!  I'll post pics in the show and tell section...

Thanks again!

[Kaz]

Hi Janie
I have the same problem as I batch anneal and use vermiculite (heated in crock pot) to cool too. I am pretty sure with mine it is thermal shock when I have not been concentrating on keeping the whole bead warm or put it into the vermiculate with some bits hotter than others. In another strand someone suggested that you may need to change the annealing schedule when batch annealing to compensate for larger beads but I must admit I haven't done that - some have survived all of the processes and others have fallen at various fences (as you describe) - it is annoying - not so much the waste of glass as the time it takes to make them and then to lose them. Let us know if you start to have more success and share your tips with us.
Kaz

[TheJanie]

Hi Kaz,

I think the main problem was that I was forgetting to keep the whole bead warm (too mesmerised by the way the glass was glooping )  It probably wasn't helped by using the Reichenbach glass.

I decided to try again, taking the Reichenbach out of the equation and trying to remember to keep the whole thing warm.  I've posted the successful (yay!) results on this weeks Show and Tell here: http://www.frit-happens.co.uk/forum/index.php?topic=5967.msg109578#msg109578

Once I've got it into "muscle memory" that I have to keep the whole bead warm, I'll try the Reichenbach again and let you know the results - but I think I'll wait until I've got a few successful ones (sans Reichenbach) under my belt first!

Cheers...

[Kaz]

Hey, well those look great! I wll start saying a mantra in my head - keep it all warm, keep it all warm - I have a few legless goddesses tonight!!!
Kaz