Always with the cracking!

bigpurpleb · #1 2012-09-16, 10:18am

Errrgh...

Hi people, I've got another newbie problem. All of my beads are cracking. Almost every single bead I've made has cracked in the kiln, and it has gotten progressively worse since I started working. What am I doing wrong? I've made about seven marbles, none of which have cracked. I also threw together two really weird little figurines and one of those cracked. Am I not putting them in soon enough? I haven't heard, seen, or felt any of the beads crack before putting them into the kiln.

I use a minor torch, a Chilli-pepper, Moretti and Vetro glasses, aaaand.... that's it.

Help!

Thanks guys,
Cowboy

Eileen · #2 2012-09-16, 10:31am

Can you post a picture of the cracked beads? Are they cracking along the mandrel, or zig zag through the bead?

bigpurpleb · #3 2012-09-16, 10:38am

I'll try and get a picture. Some are cracking at the ends, around the hole through the bead. Others are splitting in halves or thirds along the direction of the mandrel. The ones that crack at the ends stay together otherwise and the ones that split completely have smooth breaks.

Polgarra · #4 2012-09-16, 10:48am

It might help to describe your procedure as you torch.

Once you are done how long until you put it in the kiln? How hot is the kiln? What glass are you using? The more details the more likely you will get helpful advice.

Eileen · #5 2012-09-16, 10:51am

From what I've read, the ones cracking in half, thirds, etc. along the mandrel got too cool before you put them into the hot kiln.
Do you hold them out just until they lose the orange glow, then pop them in the not kiln?

Dasi · #6 2012-09-17, 5:35pm

Are you keeping the bead nice and hot with insurance heat while you are working on a bead? You can't let the heat go out of certain parts of the bead while working on other areas. Make sure the heat is equaled in the bead before you put it in the kiln.

Molly Bird · #7 2012-09-17, 7:29pm

Have you made sure your annealing schedule is correct? Maybe they are cooling too fast in the kiln. I anneal at 968-973 & after the last bead goes in, I give it an additional 30 minutes soak time (I usually make about 12mm beads.) I ramp down to 800 at 150 degrees an hour and hold for 45 minutes, then ramp down at 350 degrees per hour to 350then shut off. This is probably ultra conservative, but it works for me. I think cooling too fast is the main reason beads crack.