CIM cracking

Rachel · January 08, 2009, 01:41:05 PM

Nearly all the beads I made Tuesday using CIM ginger as a base have cracked -

One set had Effetre amber and silvered ivory over ginger and the others were CIM Sangre and Clockwork layered over the ginger. The ones that haven't cracked are where the transparent hasn't fully encased the ginger. My guess is that it doesn't like being encased. Any one else had any problems with it?

garishglobes · January 08, 2009, 02:19:30 PM

I believe there are a few CIM colours that aren't so hot on being encased, not sure if ginger is one of them?? I have to say, I've stopped encasing CIM just to be on the safe side - and because I was getting fed up with the cracks!

Trudi · January 08, 2009, 02:20:22 PM

I know that Celedon doesn't like to be encased with lauscha - it works fine with Effetre diamond.

You do have to be careful as some of them have to annealled at different temps - I'm not sure of ginger is one of them or not??

You can always email Kathy at CIM - here is her email Kathy@CreationIsMessy.com - she's always been very helpful when I've asked her questions.

Let us know how you get on!

Trudi

turnedlight · January 08, 2009, 02:20:29 PM

I find beads I make with the milky colours like halong bay have a tendancy to crack..

Trudi · January 08, 2009, 02:25:09 PM

Quote from: turnedlight on January 08, 2009, 02:20:29 PM
I find beads I make with the milky colours like halong bay have a tendancy to crack..

Halong bay is one that need the annealed at a higher temp - here's part of the email I had from Kathy:

You don't necessarily need to adjust to the highest temp – the lowest should be fine and also prevent your Moretti from slumping / sagging.

Cirrus 521 degrees C

Halong Bay 549 degrees C

Peacock Green 538 degrees C

I would turn up your annealer from 520 as a precaution. A lot of testers annealed at 520 C and did not have problems but as a best practice it really should be higher.

I haven't tried using my Halong much - but does anyone here know that If I turned my kiln up to 549°C - if my effetre glass would be ok?

Be good to know!

Thanks

Trudi

turnedlight · January 08, 2009, 02:29:08 PM

Oh that's interesting, I will tweak my temperatures!

Trudi · January 08, 2009, 02:33:20 PM

I have emailed Kathy as I wanted something else - so hopefully she will look in here (fingers crossed).

I don't think there are that many that have to be treated a bit special - but I was thinking of printing off a chart and making notes - which I can have to hand. CIM do some great colours and many of them are far easier to encase than effetre!

Rachel · January 08, 2009, 02:58:47 PM

Thanks for the information Trudi. I will try setting my temps a bit higher maybe to 520 and see if that makes a difference. Trudi - I don't know if I would go as high as 549 c - I think the Effetre might not do too well at that temp. Although I'm not exactly sure what temp Effetre would slump at but I would have thought that the softer opaques could do at that temp.

Trudi · January 08, 2009, 08:36:59 PM

Quote from: Rachel on January 08, 2009, 02:58:47 PM
Thanks for the information Trudi. I will try setting my temps a bit higher maybe to 520 and see if that makes a difference. Trudi - I don't know if I would go as high as 549 c - I think the Effetre might not do too well at that temp. Although I'm not exactly sure what temp Effetre would slump at but I would have thought that the softer opaques could do at that temp.

I wasn't sure bout that either - I might try one day when I don't have too much stuff in the kiln just to see what happens!

ejralph · January 08, 2009, 11:48:02 PM

you could run some glass rods through the kiln at the test temperature, supported on stilts and see if they sag. Remember to include known stiff colours and known droppy colours though (please, no jokes. Tan that includes you ;-)

Saves wasting any real beads.

Although I think the slump point of effetre is higher than that anyway - can't remember off-hand.

Personally I have found CIM to be a bit too temperamental for my liking. Which is a pity as they have some gorgeous colours.

Emma

mazmeabead · January 08, 2009, 11:56:25 PM

I made lentil beads with CIM Chalcedony & CIM Electric Avenue but with some98coe frit from beadgoodies.com around their middles and encased in eferetti clear and annealed at 980 and more than half of the beads cracked...

This could have been the frit though .

Maz

Trudi · January 09, 2009, 10:03:54 AM

Quote from: ejralph on January 08, 2009, 11:48:02 PM
you could run some glass rods through the kiln at the test temperature, supported on stilts and see if they sag. Remember to include known stiff colours and known droppy colours though (please, no jokes. Tan that includes you ;-)

Saves wasting any real beads.

Although I think the slump point of effetre is higher than that anyway - can't remember off-hand.

Personally I have found CIM to be a bit too temperamental for my liking. Which is a pity as they have some gorgeous colours.

Emma

Good idea - and could use half rods!

Rachel · January 09, 2009, 11:13:03 AM

Quote from: ejralph on January 08, 2009, 11:48:02 PM
Personally I have found CIM to be a bit too temperamental for my liking. Which is a pity as they have some gorgeous colours.

Emma

I agree Emma. I can't be doing with temperamental glass - that's why I've never bothered with Lauscha tbh. It's a bit concerning though - now I'm wondering whether any beads I've made with the ginger before are going to be OK. A couple of the ones from the set have cracked over the last day or so which just goes to show that just because something comes out of the kiln ok it doesn't mean it's not going to crack at later date

So now I'm a bit confused. Does this mean that some of the CIM is incompatible with Effetre? The advice is to anneal higher but I'm wondering whether even doing that would make the beads stress free. Are they still likely to crack at some point?

ejralph · January 09, 2009, 04:40:31 PM

My gut feeling with the CIM glass is that the viscosity is too different to other 104 glasses which is why there seems to be so many problems especially with encasing. CIM also seems to be very heat sensitive to me, and will crack on me in the flame even and hates being chilled by presses. Life is too short. I can't even get CIM to play nicely with itself, so for me it would be a tall order to even try using it with Effetre.

As to if your beads will crack later - well who knows. I had some Czech glass beads I made once that took a long while to go. I actually had to keep them in a box as they kept exploding. It took about 6 weeks, but one by one, they all went. It was so bad that Mr Man seriously wanted me to wear eye protection each time I opened the box to see who had died next!

Mostly I find though the beads will crack a day or two after cleaning if they are going to go. But there are no guarentees really. It can be a good idea to quarentine new colour combinations for a week or two, just to see how they go before selling them.

Emma

Kaz · January 09, 2009, 08:45:45 PM

Does anyone know whether these CIM colours would behave OK if encased with CIM clear glass or would it still be the same issue. I have used some of those dodgy colours but not encased them. At that point I was batch annealing and did them on the same programme (had not had any info from sellers that there were any differences in the annealing requirement). Anyway I had them for a while before selling and did not have any cracks appear later.
Kaz