As I noted in my response, someone would come along and be wiser than me. I can only speak to what I have experienced. I used glass threads made for copper enameling within lampworked beads and the beads sometimes held together, but more often than not, fell apart even after annealing in a kiln. (I started learning on a Mapp gas torch with Cindy Jenkins way back when and started experimenting with the glass threads because I figured all glass would work together.) I used those same glass threads in experimental fused pieces and viewed the results through a polariscope to find that there was halo around the threads suggesting an incompatibility.
A nephew had a similar problem with the same kind of threads.
Perhaps the problem is with the age of my glass threads or the fact that these were specifically for copper enameling. I know that in the class I took with Kate Fowle Meleney on copper plating beads a couple of years ago, she talked about working with the Thompson people in Kentucky about coming up with enamels that could specifically be used with various COEs of glass. I was happy to hear about the I’ve since ordered enamels and such from Thompson and used them with no problems.
I have since looked at the glass thread assortment at Delphi Glass, but I haven’t used them. I wasn’t aware that they carried them and say that they are usable for all kinds of work– copper, glass, art clay and so on. I think we might be talking about different glass threads, but I’m not sure.