Beads Shattering

[cherie]

I hope someone can help me with this. I am on a HH and making small beads, I am setting my kiln (paragon caldera) at 960, bringing the temp down to 700, holding for 1hr. and then dropping down to room temp. The problem I am having is when I try to take my beads off the mandrel they are literally shattering in my hands. Not all of them, but most of them. I have learned to wear a glove on the hand that grasps the bead. My fingers were getting cut up from the glass. What could I be doing wrong?? I thought at first I was making too big of beads for a HH around 1inch, but this is happening to even the smallest beads. Am I annealing them wrong?? Im following the instructions from my manual. I use FF bead release and just read that it is better to dilute it with sterile water, I didnt do this, I used tap water. Could that be the problem?? Any input would be appreciated as I just got the hang of making cute little round beads with nice puckers and they are just shattering in more than two pieces...Help!!

[cherie]

One more bit of info. that may be affecting this??? My bead door is partially open when they are annealed since the mandrels are sticking out of the kiln...could there be too much cooler air getting in and they are not getting annealed correctly??

[AKDesigns]

You may be putting the beads in the kiln too cold. Make sure they are glowing when they go in. But I'm curious....what glass are you using? Are you sure you didn't mix up two coe's?

[AKDesigns]

Originally Posted by cherie

One more bit of info. that may be affecting this??? My bead door is partially open when they are annealed since the mandrels are sticking out of the kiln...could there be too much cooler air getting in and they are not getting annealed correctly??

Mine do that too. The kiln just has to work harder to keep the temp up is all. I have put a fiber blanket tucked up along the bottom and sides to block some of the hole up though. That's not your problem.

[Toni Lutman]

If they're shattering, it sounds like there might be stress fractures from incompatibility. What glass are you using? Are you sure you're working with compatible coe's?

Your mandrels sticking out shouldn't be a problem. Many bead annealing kilns are like this, and the temperature adjusts to account for it.

[cherie]

Im using the starter pack of Moretti 104 coe...Im not mixing up colors too much, but Ive tried making little hearts using clear and reds from the specials that I have. Ive been practicing on making nice round beads. So when I first sit at the torch, I will make 10 spacer beads using just one color. A lot of these are shattering also. The starter pack included one rod of transparent, opals and special colors. I have a coffee cup full of shattered beads. Some are just breaking in half, but most are just shattering in a bunch of pieces...its like the glass is soo fragile and cant stand to be taken off the mandrel without shattering...Ive also joined a x-mas exchange and I was practing on x-mas light bulbs..I finally got the shape just right..Im using two colors..either a transparent or solid color for the bulb and black for the bottom of the bulb..Ive made about 20-25 of these and none of these have survived...I know there must be something Im doing wrong, but I just dont know what.

[cherie]

Thank you for your replies so far..If anyone has any more suggestions..I am wide open and all ears/eyes...Im going to go do a search and see what other ppl are doing for their annealing process...Could I be bringing the temp from 960 down to 700 too fast??

[MaryBeth]

Originally Posted by cherie

Thank you for your replies so far..If anyone has any more suggestions..I am wide open and all ears/eyes...Im going to go do a search and see what other ppl are doing for their annealing process...Could I be bringing the temp from 960 down to 700 too fast??

You should be holding at 960 for at least half an hour after you complete your last bead - longer if you have bigger beads in there.

Then you should ramp down your kiln at probably no more than 100 degrees per hour. I use a very slow ramp down schedule of about 50 degrees per hour but I use a lot of silver and glass other than Moretti.

I'm thinking you are dropping your temperature too fast. Slow it down and see if that helps.

[MelissaQ]

But don't thermal shock beads usually just split down the middle along the mandrel line?
That's been my experience anyway. And I have a Paragon Caldera kiln and the door is always open with the mandrels sticking out. But I have never had a problem with cracking. I hope you are able to figure out the problem!

[pam]

Shattering does sound like compatibility problems, however your annealing schedule could be the problem also (breaking in half).

When you turn a kiln to a specific temperature it drops fairly fast to that temperature, especially with the door partially open. Thermodynamics tell us that any container of heat seeks to equalize with the mass of air around it as fast as possible. The bigger the difference of outside temp to inside temp in your kiln, the faster the drop of temp inside the kiln. This is exactly the opposite of what you do when annealing. To anneal glass you have to slowly drop at the high end of your temperature by turning the kiln down very slowly in small increments. Mary Beth is right, no more than 100 degrees an hour is probably what most people use and that means around 1 1/2 degrees a minute. It doesn't mean you are holding at 960 and turn the kiln to 860 and leave it for an hour. Your kiln will drop to 860 in a matter of minutes. The inside of the bead will still be 960 and the outside will be 860 (an exaggeration, but as an example). A bead has to cool the same inside and out, because glass contracts as it cools. If the outside is cooler it contracts more than the inside and thus splits in half to relieve the stress. So, your best schedule will be to turn the kiln down perhaps 50 degrees and wait a half hour or 45 minutes, then another 50 degrees, etc., until the kiln is below 800 degrees. A lot of people still cool at the same rate of 100 degrees an hour down to 600 or even 400 to prevent thermal shock to beads, especially if they are larger. However stress cracks due to annealing won't happen below around 800 degrees.

Another thing you might want to consider is that your kiln controller may not be reading the correct temperature. It might be saying 960 when it is only 860.

The other possibility I was wondering about is whether you are allowing your beads to get too cool during the beadmaking process. Perhaps the bead is actually cracked before you put it into the kiln.

Just some things to think about.
Good luck.

[TheGlassFlame]

I learned about this as a possible cause for cracked beads... you could be cooking the bead release too much before you are applying your glass.

[*Sally*]

Originally Posted by cherie

but Ive tried making little hearts using clear and reds from the specials that I have.

This could be part of your problem, reds / specials and corals in particular are some of the colours that don't really like being encased.
With the bead size you're talking about you could try starting off with a layer of clear and then the reds, then more clear for the encasing.

[Wonker]

Are you using a clear that didn't come with the sample pack? Sure sounds like incompatability rather than thermal.

[Beckah]

I use the annealling schedule that I got from Paragon with my bead collar which is:

ramp full to 1000 hold for 4-5 hours depending upon length of beading session
ramp 200 to 700 hold 0

I think because the thermocouple is above the door and the bead door is cracked open, that the higher temp is needed to be closer to the 960. At the end of my session before I hit the "up" key to go to the 2nd step, I do my clean-up & shut-off's, so that my last bead sits for at least 10 minutes before I go to the ramp down. I was initially worried about so high a temperature, so I cut fiber paper to cover the bottom of the kiln. I do prop the end of the mandrel on a kiln post when I first put it in, but I move it onto the floor of the kiln when I put the next bead in. But there's never been any kiln marks (except if it goes in too hot and I miss the kiln post) so the 1000 hold isn't too hot.

Anyway, I spent a summer trying to break up some fugly's to fuse 'em and those beads survived hammers so I'm sure they're annealled.

[sculptorgirl]

That's waaaay too much breakage!

I rehydrate my Foster Fire with tap water too, so that isn't it.

The ones that are cracking down the line of the mandrel sound like thermal cracks, the ones that have cracks all over sound like compatiblity issues.

The Paragon bead collar annealing schedule that Beckah (butterfly rancher -- lol!) posted sounds really good for the bead collar, which it kind of sounds like you have, since you said you have a Caldera.

What really puzzles me is that small, spacer-sized beads (maybe 10mm or less) can often survive for a really long time without being annealed (for those who do bulk annealing), so if those are cracking for you too, there may be a problem in how you're working.

Most books say to watch the glow go away before putting your bead in. If you're doing this, it may be that you are waiting too long before putting your beads in the kiln. The glow doesn't have to disappear completely -- the idea is that you don't want the bead to still be fluid and distort it's shape because it was still too hot.

Hopefully you will be able to solve your issues soon!

[cherie]

Well I rescheduled my kiln this morning. Im afraid I was bringing the temp. down too fast. I had it set at 960, hold for 2hrs..then dropping to 700..I programmed it to drop 50 degrees an hr. down to 600...I will see if this helps and let you know.
Thank You all so much for your replies. I looked at my instruction manual and I didnt see anything about slowly dropping ..I did read where the beads needed to soak. I will find out tonight if this is what I was doing wrong.

[Carolyn M]

Cherie, I would make sure your bead is glowing before you put it in the kiln. Another newbie I knew was making a bead, taking it out of the flame to admire it for way to long, then putting it back in the flame at which point it would crack (she didn't realise it at the time) Those beads would literally crumble when she tried to take them off the mandrel

[Gelly]

I agree that it's probably your annealing schedule.
I garage at 950, slowly ramp down to 850, hold there for a bit, slowly ramp down to 600, then off. (I can't remember the exact hold and ramp times)

Let's not forget when we water anneal something or make our own frit... we go straight from the torch to the water which causes the glass to shatter and it's from thermal shock, not compatibility.

[sculptorgirl]

Originally Posted by Gelly

Let's not forget when we water anneal something or make our own frit... we go straight from the torch to the water which causes the glass to shatter and it's from thermal shock, not compatibility.

That's very true, and that's hard-forced thermal shock.

It's pretty easy to make a small bead with Effetre (10mm or so) and just leave it out to "air cool" and it won't usually even break, let alone shatter (like when you put it from torch to water). That's why Cherie's problem seems so weird to me. I'm very interested to see how she solves it!

[Jenn L'Rhe]

Cherie:
This may sound silly but when you say you are ramping to 960, holding for 2 hrs, then ramping down, are you holding for 2 hours at 960 after you finish making all of your beads, then ramping down or is the 2 hour hold while you are making your beads?

You should be ramping up, after reaching temp-make beads, when finished making all beads-hold for atleast 1/2 hr, then ramp down slowly as MaryBeth said. Getting your kiln programmed correctly can be very tricky.

If you are batch annealling, I think the ramp up is slower. But you would hold for around 2 hrs and then ramp down slowly. (I have never batched, so this may be incorrect.)

Hope you get it figured out....nothing worse than watching hard work shatter before your eyes.
Kay
(Mom to Jenn, Lu and Rhe)

[cherie]

Hi Ya'll
Im so excited!!
The beads I made came out just perfect!!
You all who said I was bringing my temp down too fast were right. I only made ten beads. I just made some different size spacers from small to large to see if they would survive and no breakage what so ever..I also think I was admiring my bead for too long before sticking it into the kiln..lol..Thank You all who had replied..Im so happy..I can now make some cute little christmas bulbs for the exchange

[MaryBeth]

Great news! Now you need to show us the beads

[AKDesigns]

I'm glad you got that figured out!

[extexnick]

You may want to cruise down to your favorite glass supplier and get a few rods from them and see if the shattering happens with that glass. I got a starter pack when I started and had problems with several rods, making solids, decorated and encased beads. I trashed those rods and haven't had the problem since then.

just a thought

[sculptorgirl]

That's great that your beads have survived! I hope that all of your problems have been corrected!

[pam]

Congrats, Cherie. Great work!!

[Anzie]

Cherie I have a paragon as well and am on a HH. I got a great schedule from a Paragon dealer for batch annealing with this kiln and garaging
It might help you out a bit?

Batch annealing

PRO1
Ramp1 150C per hour
Temp1 510C
Hold 1 60 mins
Ramp2 80C per hour
Temp2 370C
Hold2 0mins
all the rest set to 0000

Normal working program,,garaging

PRO2
Ramp1 700C per hour
Temp1 500C
Hold1 6 hrs or however long you intend to be working.
Ramp2 100C per hour
Temp2 510C
Hold 2 30mins
Ramp3 100C per hour
Temp3 370C
Hold3 0000