Fused and Slumped Sampler Platters

The Sampler Platter fused glass class is officially over and it was incredibly successful! I'm so happy with the plates that my students put together!


This is a detail shot of one of the plates. You can see the blue tile in the middle that was made during the frit, powder and stringer session has been capped with clear glass and accented with a tea light flame worked star-shaped stringer. As always, the dichro bits just don't photograph as strikingly as they appear in person.

This plate makes me think outer space, galaxy, the next frontier...Cool, huh? Great job, Alycia!


My plate was not as successful...Don't get me wrong, it showcased every possible technique I could think of for a beginners' class, to a fault! Unfortunately, some incompatible glass found it's way into my scrap bin. What?!? How the heck did that get there?!?

So, how do you tell it's incompatible? Well, if you've been following me for long, then you know I've run into this problem before...and thankfully, it's only MY plate that's ever affected! So, as soon as this plate made it's way out of the kiln, I knew something was amiss...

If you look closely at this photo, you can see the hairline fractures at the edge of the two blue squares. See that? That's incompatibility. The crack follows those blue pieces too well to be anything else! And guess what else? When I scored my plate to free the pieces, the knocks with the hammer (gentle taps on the underside of the score) broke those pieces out almost perfectly! So, after removing the blue glass, I refilled the voids with some aventurine green scrap pieces to melt back down into one. It's currently in the kiln, and with any luck will be a slumped platter within 24 hours!

Here is the other platter from the class that is awaiting a slump firing. It is also currently in the kiln. My new-ish Paragon Pearl-22 and I are still getting to know each other. The first firing just didn't fire hot enough or long enough and I wasn't happy with the fact that you could feel the seam between pieces on the underside of the plate. With Pooja's permission, I also drilled a little hole in the middle to see if I could squeeze the biggest bubble out. We'll soon see how well that turned out!

Incompatible...Glass, that is....

I've been meaning to take and post these pictures for quite awhile, now. So, don't fret yourself by thinking that my gorgeous blue and orange ribbon stitched quilted plate has suddenly shattered!

No, this plate is the first generation plate; the one made entirely of scrap glass, and because of that, alas, I found some incompatible glass laying in the wrong bins at the studio. However, this "unfortunate" incident lends itself nicely to a fabulous learning experience.


Many beginners to glass fusing ask if they can use old stained glass scrap that they've got lying around. The broad answer to that question is "No" due to reasons of incompatibility. You see, glass that has been specifically formulated for fusing "plays nicely" only with other glasses that have also been specifically formulated in the same way. The label "COE," or "Coefficient of Expansion," is the general term that describes the rate in which glass expands and contracts upon heating and cooling. If you are using two glasses that have different COEs for fusing purposes, then your final result will end up looking similar to my lovely sample plate. (Again, the COE will generally get you through the long explanation, but if you want all the juicy details of compatibility, check out TechNotes 3: Compatibility of Glasses from Bullseye.)


However, you may not have a disaster like this the first time out of the kiln! For reasons best left to the Glass Gods, this particular plate did not crack until after it's second time out of the kiln. Only when I was engraving the bottom of the plate did it "pop" in two cracks diagonally down the middle. Initially, I thought it was my engraving that broke the plate.
So, I put the plate back in the kiln to fuse it back together at a full fuse, once again. Fortunately, the third time out of the kiln was a total crack up, around each and every one of the orange pieces, allaying my guilt at having cracked my plate upon engraving.

So, what happened?!? By looking at the slivers that have formed in circles surrounding almost each and every piece of orange glass, we can be suspicious that this glass is not compatible, which all of the other glass that I was using happens to be. In other words, the rate at which the orange glass contracted upon cooling was slower than the rate at which the rest of the glass contracted. As the glass became less fluid, the only way for it to get rid of all the stress building up inside was to crack!