Diagnose a crack for me?

[Eileen]

This bead was fine when it came out of the kiln Saturday night, but I just took it off the mandrel & cleaned it tonight.
I just noticed it is cracked now, and am not sure what happened.
It's CIM Azure, with some silver leaf inside. I think it has a clear core (Eff 006) but can't remember for sure.

It isn't along the mandrel, but there is just the one crack, so far at least, so even if it was the clear core or leaf I would expect more wouldn't I?

I garaged & annealed at 925-930°

[KJohn]

Just thought Eileen, that it might be a pressure crack? How did you get it off the mandrel?

[Eileen]

Just my normal twist & pull. It didn't take any unusual effort that I remember, but maybe I put my fingers in a bad spot I suppose.
I hope the ones I've sent to BOC don't crack. This one I left the fins & tail a little more pronounced though I think.

[gemsinbloom]

Sorry about your bead. I have no luck mixing transparent Effetre and CIM glasses myself.

[echeveria]

That annealing temp might be a little low.

[RSimmons]

Your soaking temp might be a bit low, I'd go to 950, but this looks like compatibility cracking to me.

Robert

[tiggybubba]

I am getting very discouraged with glass these days. I have about a 75% failure rate. Not ugly beads but compatibility cracks. Even when you stick to one manufacturer. Like tag with tag.

[glasshouse]

Leslie, what bead release are you using?

[Eileen]

Thanks everybody.
This glass stuff is more complicated than it looks!
I dropped my temp to accommodate learning silver glass, and upped my soak time. Maybe I need to have a couple of schedules, silver/regular/CIM/etc.
sigh~~~~

[beadbroad]

It may also be a thermal crack that started while you were still working the bead. Fish'll do that to you while you're working on the fancy bits.

[Eileen]

Would that take a few days to show up, like this one did? Or maybe it was there but tiny, & my taking it off the mandrel make it grow?

[ewdb]

Originally Posted by Eileen

Would that take a few days to show up, like this one did? Or maybe it was there but tiny, & my taking it off the mandrel make it grow?

yup, looks thermal to me. i find for sculpted beads thermal cracks aren't always straight & sometimes they start as a nick or bubble and then extend over the next week or so into a full long crack.

Also when using Effetre under CIM (or any other stiff glass), it needs a super even encasing layer, i always do two coats to be sure - or else it might be inclined to crack.

And yes, i'd up the annealing temp as well... cute fishie tho!

[Lyssa]

I made 11 CIM Coconut Milk encased in transparent beads last and six of them cracked, from hole to hole. I used various transparent colors, including 2 CIM Azure. Both of the Azures cracked. Can't remember what the other transparents were that cracked.

Oh, forgot to mention that these were all medium small round doughnuts. Nothing fancy but the encasing. I garage at 930 to save electricity costs.

[cinder]

I seem to recall Joy Munshower (the lady who makes the octopus beads, for those of you who don't know people by name) saying just a few weeks ago that she was having a lot of compatibility problems between CIM blues (including Azure) and Effetre. I don't know what she did to remedy the problem, just that she was experiencing it.

[tilegoddess]

Alrighty... so I had the opportunity to chat with Kathy, the owner of CiM at the Gathering this last summer in Bellevue, WA. She said that the CiM "blues", opals and moonstone colors need to be annealed at a higher temp... 1050-1080. I used to anneal at 950 like I was taught in beadmaking 101, but lost 50-75% of my CiM beads due to cracks (for various reasons). I now anneal at 1050 as I use a lot of CiM colors, and my crack rate has dropped to about 10%-15% (acceptable to me).

CiM does tend to be a bit finicky, beautiful, BUT FINICKY! I use CiM Azure over Periwinkle or Lt. Blue and it's been fine. I hear a lot of people say that they get compatibility cracks days after the bead comes out of the kiln when they either encase the CiM over clear or have encased the CiM in clear.

I am no expert guys... I didn't chime in on this thread sooner because I wasn't sure I had a whole lot of info or insight to share.... I get weird cracks too now and then, usually in blue glass colors, but I get them in both CiM AND Moretti. My last bout of weird compatibility cracks were my Deep Sea Angler Fish beads where I encased Eff. Raven Sky with Vetrofond Medium Blue transparent.... it wasn't even CiM and I got compatibility cracks 2-3 days after they came out of the kiln Another set of horse beads developed weird compatibility cracks and it was solid Eff. Laguna Blue (bad batch??).

All I can additionally say is that I keep notes on my finicky colors and who they play well with and who they don't...

[Eileen]

Thanks for all the insight. I'll get a notebook for keeping track of problems (thankfully few so far) with glass compatibility, and try to avoid creating trouble.

I will try to figure out what I'm making ahead of time so I can set the kiln accordingly (silver glass lower, CIM & Lauscha higher, etc.). That is going to be a big change for me, I usually just sit down & see where the glass takes me

[Elizabeth Beads]

I rarely have cracks with Messy Color. I mix with other 104 glass, I garage and soak at 925 for 1.25 hours before slowly ramping down. I have beads that are years old made this way with no issues. The only inconsistent results have been encasing oranges and reds and that is no different than with any other manufacturer.

Make sure you have nice even heat going into the kiln. You don't want half the bead glowing and half the bead cooler, you want a nice even glow. Fish can be tricky since you have the sculptural elements to contend with.

[Eileen]

Elizabeth, that is pretty much my kiln setup lately. I am holding for the hour fifteen to make up for lower temps. Maybe I'll continue & see if I have any more problems. I will also be more vigilant about the fins being hot going in. I thought I'd been doing that, but maybe I slipped up on that one.

[Moth]

Because the crack goes from the mandrel to the front edge of the bottom fin, I'm leaning toward thermal. A stress crack from a thermal weak point to another thermal weak point. Sticky outy bits are tricky.

I agree that your garaging/annealing temp is kinda low. I garage/anneal at 960-980 but you are still technically within range.

That said, though. I've experienced the same thing Joy has described with CiM blues and moonstone. Especially the moonstone. I've also heard that some of the CiM likes to be annealed really hot. I don't do this because I use a lot of enamels and if I go that high it is really sticky. So, I anneal between 960-980 and soak for a really looooong time, and ramp down really slowly. The moonstone still hates me so I rarely use it. I didn't want to change my annealing schedule for one color.

[Lyssa]

Maybe my problem with cracking beads is that I tend to start my ramp down just as soon as I've finished my last bead... but wait, I did the two Azure beads first, so they were sitting in the kiln for maybe two hours before I started the ramp down. What the what?!

Ok, maybe I'm forgetting to bathe the beads in heat before putting them in the kiln.

Originally Posted by Elizabeth Beads

I rarely have cracks with Messy Color. I mix with other 104 glass, I garage and soak at 925 for 1.25 hours before slowly ramping down. I have beads that are years old made this way with no issues. The only inconsistent results have been encasing oranges and reds and that is no different than with any other manufacturer.

Make sure you have nice even heat going into the kiln. You don't want half the bead glowing and half the bead cooler, you want a nice even glow. Fish can be tricky since you have the sculptural elements to contend with.

[tammydownunder]

I had major cracking issues when I was using blue sludge bead release.

[flaming_fools]

Our garaging/working temp is 975 - our anneal is 940 for an hour - and another hold at 820 or so for at least 1/2 hour on the cool down.

We don't use CIM - is that a 104 glass? Seems like awfully hot temp needed for annealing.

We use Effetre, Double Helix, and ASK (Arrow Springs Kugler 104) exclusively, with a bit of Gaffer Chalcedony once in awhile, and possibly only have compatibility issues/cracks in maybe 4 beads a year.

Also, we never use any of the 'blue' sludges or 'flame dry', as they have been nothing but trouble.

[MelanieG]

I think that your crack looks like it started because that end of the bead got too cool while you were working it, but not quite cool enough to really pop. When I was still pretty new, I used to have that problem with some of my long bicones, and the crack would start on the end and then just wander up the bead a little in a similar way, although my problem beads were all opaque.

I mix CiM, Effetre, Reichenbach, Kugler and Lauscha glass pretty liberally when I make beads, but I also test each new colour to get a feel for it before I start making beads that I want to be keepers. For instance, while doing my colour tests for Lauscha Apple Green, I recently discovered that there's a cracking problem that happens when I encase Lauscha Apple Green with Effetre 006 Clear.

I can't really point to the Apple Green as the problem, because I've made beads with it where it came into contact with both Effetre and CiM glasses but was not encased, without any problem at all. I also can't definitively claim that Effetre Clear is the problem. While it has cracked for me with a number of different CiM glasses, I've used it with way more other colours with zero issues.

What I decided to conclude, since both colours behave perfectly well in other combinations, is that encasing stiff Lauscha Apple Green with a Clear that is as runny as Effetre 006 is just not a great idea. My understanding is that there are quite a few reasons that two glasses can seem not to get along, even if they are both within a particular tolerance of 104 COE. I don't know all of them, but differing viscosity is one that I remember. The other possible cause of the cracking that I had might be that Apple Green simply doesn't like being encased. I think that all of the manufacturers make a few colours that have this problem.

I didn't personally have cracking problems when I tested Azure with Effetre 006 Clear and silver, which makes me more certain that your problem is thermal.

Pretty fish though!

[tiggybubba]

Just took some beads off the mandrel These were made using fusion/foster fire blended for bead release. TAG wicked green, tag clarity. Cracked. not a thermal crack as its not straight. Definately curving; I even raised my garaging/annealing temp. My beads soak for upwards of 2 hrs before ramping down. As a bare minimum, 60 min. Then 100 deg/hr til 860 where they soak for another hour. 100/hr to 200 then off.

Im ready to give up

[Eileen]

Maybe it's the moon, or the humidity, or....

[Hayley]

Eileen, The only way to know for sure is to remake your pretty fish with the same glasses - put on in at 960F, let it soak for 30 minutes, ramp down to 925, put another one in at the temp, then run your kiln the normal cycle.

[yellowbird]

thermal cracks don't have to be straight some are gay

[Eileen]

Hayley, I'd never have even thought of that! It seems logical now that I hear it, but never crossed my mind to try to duplicate it.

[tiggybubba]

Originally Posted by yellowbird

thermal cracks don't have to be straight some are gay

ROTFLMAO!!!!!!

[tiggybubba]

Here it is....sigh