Beads cracking

Rachel · April 21, 2010, 09:30:51 AM

Hi guys

Just a quick question.. I'm having issues with beads cracking along the mandrel line after annealing. It looks like thermal cracks but the temp on the kiln is reading the same as it always does and it feels very hot but I'm wonderling if it isn't heating consistently.

Thing is I've only noticed it on beads that I've used clear on - Vetrofond - which is the same batch I've had for the last year and I haven't noticed issues before. I''m worried that I only notice the clear ones and that the opaque ones may have developed cracks but I've not noticed.

At first I thought it was incompatability as I used CIM kryptonite and encased (which I've done before with no probs) but yesterday I used all effetre and I've just had one crack as I was cleaning it.

Do you think it's possible that the kiln isn't getting as hot - it's a kilncare Maxi? How would I test to see if the temp is right?

Rachel

Dragonfire Glass · April 21, 2010, 09:54:28 AM

Certainly indicates thermal cracking.
Maybe taking too long to get them in the kiln?
Core bead getting too cold?
Doesn't sound like incompatability so could just be coincidence with the vetrofond.

Rachel · April 21, 2010, 10:00:21 AM

Thanks Collette

I'm pretty sure it's thermal too. Thing is I'm not doing anything different to what I've done for the last few years

I just wonder if it's worth getting my kiln checked out - I think I'll email Kilncare and see what they say.

Dragonfire Glass · April 21, 2010, 10:05:46 AM

Good idea - and it may eliminate a possible cause

Lush! · April 21, 2010, 12:51:15 PM

When Kilncare's engineers are in your area they should be able to call in - I think you can track em down on Facebook

Krysia@No98 · April 21, 2010, 12:53:05 PM

I have been told that CIM kryptonite is a willing cracker and that if you give it the slightest chance to do so it will!

Dragonfire Glass · April 21, 2010, 01:19:35 PM

Never had problems with kryptonite cracking at all

Rachel · April 21, 2010, 01:34:45 PM

Quote from: Lush! on April 21, 2010, 12:51:15 PM
When Kilncare's engineers are in your area they should be able to call in - I think you can track em down on Facebook

Thanks Julie

I've been in touch with Lee and I'm going to check a couple of things later. I've made some test beads which are in the kiln now so I'll see if they survive.

Quote from: Failariel on April 21, 2010, 01:19:35 PM
Never had problems with kryptonite cracking at all

Me neither. I made some beads last year using exactly the same glass which were fine. I was asked to make some more for a customer and every one of the eleven I made cracked which was very frustrating!

Krysia@No98 · April 21, 2010, 03:39:24 PM

maybe I was hearing things $:-\$

(It's really quite possible)

Rachel · April 21, 2010, 04:40:28 PM

Quote from: Krysia on April 21, 2010, 03:39:24 PM
maybe I was hearing things $:-\$

(It's really quite possible)

Sorry I didn't mean to disregard it - I've read that some of the CIM glass doesn't like to be encased too. It's just strange that I've used it loads before with no probs then all of a sudden all the beads crack. I used effetre turquoise and cobalt and encased with Vetrofond yesterday and so far 2 of the 5 lentils have cracked aswell

helbels · April 21, 2010, 07:24:49 PM

Have you tried encasing with another brand of clear and see if that solves the problem?

At least that way you'd know whether it's anything to do with the Vetrofond or not....

Krysia@No98 · April 21, 2010, 07:55:17 PM

Quote from: Rachel on April 21, 2010, 04:40:28 PM
Quote from: Krysia on April 21, 2010, 03:39:24 PM
maybe I was hearing things $:-\$

(It's really quite possible)

Sorry I didn't mean to disregard it

I didn't think you were

mel · April 21, 2010, 08:43:06 PM

I had a problem with cracking beads (mega longtitudinal cracks)...solved it by making sure mandrels are all pushed into the kiln at the end of the torching session so no bits are sticking out/conducting heat out of the bead. Not sure if you or most people do this, but it made heap big difference for me.

Rachel · April 21, 2010, 09:12:23 PM

Just taken the beads out of the kiln:

2 nuggets - kryptonite base, vetrofond encasing - cracked
1 nugget - kryptonite base, pale green transparent encasing - cracked

I also made ivory base with clear encasing and some plain transparent nuggets - none of these show any cracks yet.

So looking at it you would think the kryptonite was the culprit but the beads I made yesterday had no kryptonite in.

I checked the kiln schedule which was fine.

Mel - that's something worth thinking about although I can't really do that with the one I have as the design of it leaves the mandrels sticking out.