Leaf headpins cracking?

[solar]

(Hello new here)..I've been trying to make leaf headpins using a leaf masher, and find there is often a crack formed just where the wire goes into the glass..

I've been slowly backing them out of the flame and putting them straight into cooling bubbles to batch anneal later.. Is this what is causing the cracking? (I didn't want to have the kiln blazing away all the time.. ) Is the copper wire conducting cold into the hot bead? Does anyone have any suggestions as to a way to make them without them cracking?

[solar]

I think I may be holding them in the press a little bit too long.. that might be part of the issue..

[Three Muses Glass]

It could be something like the thickness of your wire compared to the mass of glass.
But if you think they're OK, try putting them in the kiln directly. That way you'll know for sure if it's the wire/glass ratio, a direct annealing issue, or what the problem might be.
Different wires are good to try too. Nichrome, kanthal, brass...
And welcome to here.

[solar]

Thanks Rebecca, Yes, I need to experiment I think.. the wire is 0.8mm. I may try the direct to kiln thing if I can't find a solution.

[Three Muses Glass]

That's about 20 gauge then? Should be OK as long as the glass isn't too thin at the attachment point. Say about 2X the thickness of the wire.

[solar]

Yes, 20 gauge. And they are possibly a bit thin too.. Thanks for the insights.

[Floorkasp]

I never had any issues with cracking with my headpins, until I moved to a thicker gauge. Now, instead of in the bubbles, they go straight into the kiln, problem solved.
I use kanthal wire, and moved from .45 mm to .75 mm.

And I only have issues with the ones that I flatten (I am making grass leaves), not on any other ones.

[Ravenesque]

imo any glass + metal should go into a kiln, especially if you're selling them. I don't have science to back me up (I don't think?) but from what I've experienced seems to be so with the metal and glass cooling at different rates and the coe getting messy. I make some pretty flat ones without issue.

[solar]

Thanks everyone I've just ordered some kanthal wire, and I'll experiment. If I still have issues with cracking, I'll have to bite the bullet and put them straight in the kiln.

[solar]

I've just tried using the Kanthal wire.. No cracks! so it was the copper conducting cold into the hot glass. Thanks for the suggestion!