CIM Plum Unique .... updated

ruth · December 02, 2011, 10:23:36 AM

Quote from: Lush! on December 02, 2011, 09:42:21 AM
Uh oh ....

I noticed the Unique Plum side of the bead is well and truly cracked. I'm writing to Kathy Seamands at CIM now, see if she's come across any similar problem with this glass.

Totally Irrelavant Comment
I am really impressed that your nail varnish complements the bead colour. THAT is attention to detail!!

Lush! · December 02, 2011, 10:28:36 AM

I'm glad you noticed

Lilley · December 02, 2011, 11:52:57 AM

It is a real pity that this is happening with the unique plum and celedon - but on a personal note I am reassured that it is not me and my technique!! Here's hoping you do get a response Julie.

Sarah · December 02, 2011, 10:08:11 PM

Hmm I missed this

I think there is more than one unique plum - I have used one of the lighter ones (I think it is the one whose code ends with 3) in lots of beads and have had no problems encasing. I've used it with silver leaf, gold leaf, khaos & clio. But I have had problems encasing my bog standard plum which is close to the colour in your beads Julie. I'd be really interested to see what Kathy says.

Its a shame because the reactions you get from plum are gorgeous.

Kaz - I've always found CIM a bit unpredictable with encasing - I try to make test beads but you know whats it like when you find a fabulous reaction/combination and you know you should wait till the first bead is out of the kiln to make more but you just can't stop. Or is that just me?

Sarah
xxx

Kaz · December 03, 2011, 08:01:58 AM

They weren't encased though. Base of butter pecan, dots of maple, dots of butter pecan and dots of inoffensive effetre sky blue. And twisted
Here's a photo - you can see the crazing.

IMG_0161 by Kaz ~ CheekyCherubDesigns, on Flickr
Kazx

awrylemming · December 03, 2011, 08:29:31 AM

Oh my Kaz - that simply shouldn't be with this combination. The only thing you've used that isn't CIM is the sky blue, and even that is in such tiny amounts that it shouldn't make any difference. I'd be interested in seeing any reply that you do eventually get. Shame too, they are very pretty beads.

Shirley · December 03, 2011, 08:35:38 AM

The sky blue won't be the issue. The truth is that sometimes CIM isn't compatible with itself. Anyone remember a report by Corina Tettinger about how the pinks didn't play well together and that some colours need to be annealed at different temperatures?

awrylemming · December 03, 2011, 08:47:32 AM

Still, in such small amounts it's rather shocking to see that kind of incompatibility - even using a different COE of glass in those quantities I wouldn't expect to see that kind of crazing. Shame, I love using CIM but am becoming more and more careful in my selection of it due to this problem.

Kaz · December 03, 2011, 09:57:36 AM

Me too unfortunately - using reliable combinations or colours in their own.
Kazx

Sarah · December 03, 2011, 04:16:22 PM

Sorry Kaz - I misunderstood and those are so pretty. I think Shirley's right about CIM though

When it first came out there were a few issues and I remember there being annealing ranges for most of the colours. I think it was Dora who did a long post here on compatibility and there was also info on the CIM website. I don't know if we still have Dora's post but I can't find the info on the website anymore.

Sarah
xxx

Shirley · December 03, 2011, 04:46:11 PM

At least a lot of the CIM colours are so nice you can use them by themselves.

Shirley · December 03, 2011, 04:51:38 PM

Here's the info from Dora. http://www.frit-happens.co.uk/forum/index.php?topic=2276.0

There was definitely something from Corina too, probably on her website, and mainly about the pinks.

Lush! · December 09, 2011, 06:57:24 PM

I just had a phone call from Kathy following my email to her.

I'm not sure we really came up with a definitive answer to the cracking Plum Unique problem (Sarah, my Plum Unique has a -1 at the end) but it seems that its most likely to be related to annealing temp/soak time.

First of all, she explained that compatibility is not only an issue across glass manufacturers but the base formula of each glass needs to be taken into account. CIM glasses fall into five different formulae: Reds, Opals, Opaques, Transparents and Moonstones. If you look up each colour on the CIM website, you will see in the description which of these formulae it is. The Moonstones are Peacock, Haylong Bay and Cirrus and I was already aware that these require a different annealing schedule.

Using Plum Unique (an Opal) with Celadon (an Opaque) should not actually cause a compatibility issue, but they are from different formula groups so its not completely out of the question.

She did suggest a work round for any glasses that have thrown up this problem: start your bead with a base of clear as a stabiliser, then encase the clear with the coloured glasses. Also increase the soak time for any problem glasses, or make them at the start of the session so they garage for longer.

She does accept that most of us (definitely including me!) are not prepared to adjust our kiln programme depending on what glass we use so she certainly isn't saying that we should put up with this. I think the point here is that the problem has arisen in a Unique/Ltd Run glass, not a regular line. I use other Opals regularly and have not experienced a problem like this before.

Also I realised that I did anneal the two beads I've shown in this thread at different temps. My first bead, the one with Unique Plum and Unique Desert Pink, was garaged at 500 degrees and annealed at 510. But in-between making that bead and the one with Celadon, my controller was replaced, and the bead with Unique Plum and Celadon was garaged and annealed at 520. I think this actually contradicts what Kathy was saying so doesn't really get us anywhere though!! $:-\$