Imcompatability?

[helenfc]

i'm so frustrated... i made a lovely set of beads and they have all cracked as they were coming off the mandrel!! not thermal cracks (i dont think...) they were horizontal to the hole rather than along it. I was going to use them for college and now i have nothing to show for it! 
if it helps they were ivory base with blue enamel (from tuffnells so 104) silvered ivory shards and some dots with 104 glass. Any ideas, i really dont want this to happen again it took me ages to do them yesterday. grrrr.

[Les]

a good clean break seems to lend itself to thermal cracking ... from my experience, incompatability cracks are finer, and a lot like crazy paving ... i think I have a picture somewhere to illustrate incompatability ... lemme go see....

[Les]

here ... this was 104 encased over bullseye white ... doh !

[Jolene]

Aww what a shame!

[helenfc]

thanks les, thermal cracking could be the case,maybe i got a bit too keen with them.
glad its not incompatability, as I really like this recipe!
shame about the critter, he is adorable though!!

[Veebee]

I wonder if there were teeny weeny air bubbles trapped in the enamel (which you encased, yes?) It just looks to me as if the under layer has pushed the outer layer away, which expanding air might do.....
Actually, I really like it, such a shame 

[Les]

hehe ... I made him last summer, and amazingly, he's still in one piece .. just looks like he's been run over by a bus

[Les]

I wonder if there were teeny weeny air bubbles trapped in the enamel (which you encased, yes?) It just looks to me as if the under layer has pushed the outer layer away, which expanding air might do.....
Actually, I really like it, such a shame  

Tiny air bubbles won't cause cracking. We actively add bubbles to so many designs and they are all structurally sound

[helenfc]

oh vivki thats not my bead its les's one...i was thinking i havent put a photo up, how can you see me?! lol bit worrying! didnt encse the enamel, unless there were air bubbles under the shards? but it hasnt been a problem before. I btch anneal and had recently switched what i keep the beads warm with, so thats probably what the problem was.

[helenfc]

oh les got there first!  good to know about the bubbles though

[Veebee]

Doh and double DOH!!

**skulks off to go and stand outside Manda's house for a few more hours**

[Les]

LOL

[sarah t]

i dont think incombatability is the problem ...i have used ivory and enamels loads and no problems ... possibly the shards but sounds thermal to me .....mine usually crack when i am concentrating on one area and forgetting to keep the rest of the bead warm ...or pressing or shaping can be a stresser too .........but could well be the cooling process

you know the solution is a kiln dont you  

try again and good luck

[helenfc]

thanks lovelies, i think i had the same trouble with ones i made this morning. just went to take them off the mandrels and one of them broke the exact same way again. i can hear it start to crack when i take it off. so i left the other five on their mandrels intact and bunged them in the kiln for a batch anneal to see if it works. do you think it might be too late?  aaarg wish i coud anneal as i go, but my kiln and torch area are in two very diffrent places, and i cant have them next to each other. sucks, but batch annealing always worked until last week! 

[Les]

hmm .. maybe try switching back to what ever you were using to cool the beads with and see if it resolves itself