My lentils keep cracking :(

[ChaosMom]

Hello All,

I've been on the torch for about 4 months, so pretty new. My current problem that I can't seem to overcome is that when I make larger lentil shaped beads, they crack on both sides of the bead, right down the center along the mandrel line. This has happened with every one of the last six that I've made.

Am I pressing too hard when I shape them, or is it a heat control issue? Both? I haven't had one crack until the past week or so, and I'm not sure what I'm doing differently.

Any thoughts?

Thanks!

Amy

[shawnette]

That's a thermal crack. After you press the bead, reheat it thoroughly before putting it in the kiln.

[stacied]

Sounds like the bead might get to cold before going into the kiln. Try a little more insurance heat before popping into the kiln.

[stacied]

Lol Shawnette we posted at the same time.

[ChaosMom]

Thanks Stacie and Shawnette. I kinda figured it was heat related. I've been doing more with the embellishments and reduction glass and stuff, and I think I maybe need to go back to basics a little before I get too fancy!

[Afterdark]

Still having problems step down on mandrel size!

[J. Savina]

Hi Amy
Thermal shock will happen quickly if the COE's are different too. Just make sure you're not mixing more than 5% of the different COE glass.
J.