Help for Middle School Glass Fusing Project

Aloha,

I am currently a middle school art teacher in Hawaii. My college background is in ceramics, but I have also loved working with stained glass and lampworking. Now I am trying to learn how to fuse glass, but I am not happy with my first results.

Last year every teacher at our school received funds for a project and I choose to spend my money on glass fusing. I now know that COE's of glass must be compatible, but I really just wanted to make some fun cabochons with the kids to make into pendants or magnets.

I used a slow full fuse firing schedule that came with my Amaco glass kit, but I am having some issues.

I am including pictures of my pieces to see if anyone has recommendations for me. I realize that I should be using a glass fusing kiln and possibly different firing schedules, but in reality, I have 125 students that will be doing this project and was hopeful that I would be able to fire them with a simple full fuse schedule.

Photos of fused glass cabochons

https://bit.ly/2IG7Jhp

I hope you can see the photos, but issues I'm having:

1) Millefiori looks like it has cracks around it? Was it the wrong COE?

2) One of the stringers looks like it has little tiny cracks under the top clear layer.

3) One piece is dull looking, not shiny?

4) One piece looks like it didn't fully fuse, although the others did? Is it a cold spot in the kiln?

I'm sorry if this message is confusing, but I want my students to be happy with their fused glass pieces. I want them to make something that they love and will have for a long time.

Thanks in advance for any advice.

Kristi