Posted on

When Good Glass Goes Bad

fused tempered glass

One of the most frequent comments during my webinars is “We love seeing what went wrong!”  so, here I give you a selection of When Good Glass Goes Bad.  Even people with lots of experience have failures, here are some of mine.

  1.  Chip off the old block

Cast Float Glass
Cast float glass triptych

I’m pretty happy with this cast float glass triptych, there is a design of stacked squares on the back, and the outer two are curved the opposite direction from the center one.  Until I tapped the edge on my steel polishing wheel and this happened:

Broken corner

Cause:  Clumsy artist

Next steps:  I think it can be saved, but I’ll have to trim all 3 pieces to match and it will change the design slightly.

2.  So much for the molds

One of my favorite things about working with recycled glass is the lack of pressure to not waste my materials.  I experiment a lot.  So, I had a left over pile of broken up tempered glass, and decided to try a fused soap dish.  I turned a shallow stainless mold upside down inside a ceramic mold, kiln washed them both and filled the ceramic mold with the glass, plus some enamel for color.

fused tempered glass
Tempered glass chunks

Cause:  I think the enamels acted as a flux and lowered the melting point of the glass.  This in turn caused the glass to be more liquid at fusing temp and it soaked right through the kiln wash and stuck to both molds (this is a hazard of firing too hot as well).

Next steps:  Straight to the trash

3.  Test Everything!

This one is a case of ignoring my own advice.  This is an ongoing casting project using clear vintage glass plates.  Previous versions I had tested all the plates and they were compatible, so I ‘assumed’ and skipped the testing this time around.

incompatible glass
Incompatibility all over the place

Which was a very bad idea.  This is the piece of glass under polarized film the flares indicate massive incompatibility.  In fact, the glass had already started cracking before I opened the kiln.

Incompatibility cracks
Cracked Glass

Cause:  Careless work on the part of the artist.

Next Steps:  Straight to the trash

4.  Bubble who?

Here I wanted to give baking soda a try as a bubble powder.  Behold I give you:

Bubble free glass
No bubbles anywhere

Cause:  hmmm.  This one I’ll definitely try again, I sense a challenge!

Next steps:  For this piece, straight to the trash

5.  Over fire much?

This is an attempt to make a cast glass paperweight using some glass plates from the ’60’s.  I cut a terra cotta tube pot at an angle, kiln washed it and stuck it on a texture tile.  The goal was a round sloped green paperweight with a textured leaf pattern on the sloped surface.

broken paperweight
Just a little sticking

The parts that didn’t stick look nice, but, the top temperature was just a little high, and the glass soaked through the kiln wash and became inseparable with the terra cotta tube.  The texture tile is fine.  I’d used the tube for many other projects, so I know it wasn’t the tube.

Cause:  Over firing

Next Steps:  you guessed it…straight to the trash.  I want to try this one again though.

6.  Not today!

I frequently use plaster inclusions in fusing float glass, and often with shallow molds you can combine fusing and slumping into one step.  I found a cool silicone mold at the thrift store (yes, I obsessively stalk thrift stores) and wanted to give it a try.

Fused Float Glass
The definition of Not Today

Cause:  I actually think this one would work if my glass were 1″ bigger in all directions.  I’ll try this one again.

Next steps:  do I even have to say it?

So, are you going to let that one failed attempt keep you from your project?  I’d love to hear, I’ll be in the shop making paperweights if you need me.

0 comments