What am I doing wrong??!!

[honey*bee]

Every time I make a fairly large vessel it's cracked like this when I take it out of the kiln. My smaller ones are fine. What am I doing wrong??
PLEASE HELP![-o<

[honey*bee]

OOPS DOI forgot the pic...
150612

[Raven Wylder]

Looks like thermal shock to me because the edges are rough and sharp, this means that it had a stress around the lip before going into the kiln. You'll need to keep even heat throughout your beadmaking. While you're wrapping the bottom colors, make sure you go back to the lip of the vessel and give it enough heat so that it's a dull red color (not too hot, you don't want it clear). Once you're done with adding the colors, again, make sure you give the top insurance heat while you're shaping, and again right before you pop it into the kiln. Hope that helps...

[honey*bee]

Well I was letting it cool in a fiber blanket first and then annealing it so... I guess I should pop it straight into the kiln from the flame.

[JavaGirlBT]

Things with different thicknesses - like vessels with a skinny neck and thicker body - like to be put directly in the kiln. The difference in thickness makes it prone to cracking if you cool it in a fiber blanket.

[honey*bee]

Ah, I see. Thank you.

[Karen Hardy]

As soon as I put away my fiber blanket and just started
putting beads straight in the kiln - 99% of my cracking issues vanished.

[PaulaD]

Yeah I'd ditch the fiber blanket.
Paula

[samandsha]

I agree, especially with hollow forms...straight into the kiln will dramatically reduce the cracking issues. Sorry ;-(...it's pretty.

[Moth]

OH, sorry your having cracking problems...I love little vessels like that.

I agree with all the other posts. Fiber blanket and hollow forms with different diameters don't play well together. Maybe just pick a day where all you make is vessels and garage them all into the kiln together.

If you batch anneal to save time or power, you can wait until you have a big group of regular beads you want to batch...then get them all ramped up to annealing temp, let it hold there while you make and garage the vessels, then anneal them all together.

That way it won't feel like such a waste if you don't get many vessels made at one time.

Good luck!
~~Mary

[barbbbeads]

The kiln doesn't take a whole lot of power to run. Put the fiber blanket far, far away and don't use it in case of emergency or if you do a demo off-site and can't take the kiln. Straight into the kiln is your best bet. And yes, keep insurance heat all around the entire time. And flash heat the whole thing to just a glow before popping into the kiln.

[honey*bee]

What temp should I have the kiln set to, in order to garage them? I have a top loading kiln, with a pyrometer.

[Moth]

I garage at annealing temperature, which for me is 960, unless I'm using glass that doesn't like a long, hot soak...like rubino or the silvered glasses. For those I garage slightly lower or make sure they don't soak over-long before ramping down. I do those around 900, then ramp them up to annealing temp when I'm all finished before ramping them down slowly to room temperature.