Fused Glass Artistry

Posts tagged “Hot Glass



Yup, that echoed throughout my studio when I checked a kiln run that was ruinous.  I had been lured into a compulsive buy at a glass supply store.  The specialty glass piece had multi-hued green shards on top of a blue swirled opaque white sheet.  I thought it was perfect for one of my organic shaped vases.

During the initial heating process, right around 600 F, I heard a loud noise but didn’t know what it might have been.  I wasn’t about to violate the basic rules of fusing glass and look inside the kiln when it wasn’t above 1100 F.  When the temperature did reach the expected slumping point (~1200 F), I took a peek.  Oh no!

This is what I saw.


The center of the glass had split open and the entire piece had fallen down around the mold instead of slowly draping over it.  I think the noise I heard was the glass splitting open.  Maybe the glass had not been properly annealed when I obtained it?  I used my standard ramp rate for heating the glass – after holding for 15 min at 300F, ramp to 1100 F at 300 F/hour.

This odd glass imitation of a mounted fish (I could only see a big bass mouth mocking me) stumped me for many months.  What would I do with it?

Hammer time!

Yes.  I attacked this with a hammer and smashed this oddity into pieces.  I could start over.

I choose to tack fuse some of these shards onto an opaque white sheet.  DSCN1697Now it was time to try to drape this over a floral former to create a vase.


Success!!!! I’m happy with how I recovered from one fusing disaster to create something exciting.  Perseverance pays.


Less is More – Downsizing a Vase

We’ve been taught to believe that bigger is better.  When presented with a draping mold, I always made full use of it.  A mold that stands 7″ high should produce a vase that also stands 7″ high.  But of course!  In fact, I’ve been apologetic that I couldn’t produce larger, more glorious vases due to the size of my kiln.

Imagine my surprise when I got an inquiry about miniature bud vases.  What exactly did they want?  A tall but narrow vase?  A short vase?  And more importantly, what could I actually make?  I had never considered my options.

Let’s start with the draping molds or so-called floral drapers I had access to.

Floral drapers

On the right is a mold which stands 7″ tall with a top (the final vase base) that is 2.5″ in diameter.  On the left, is a stainless steel pillar also 7″ tall but with a narrower 1″ diameter.  Both have been coated with boron nitride (MR-97) which is a glass mold release and makes the shiny stainless look white.

All my previous vases started with a 12″ sheet of glass that would drape around the mold at elevated temperatures and produce a 7″ tall vase.  (See my previous post https://geekgirlglass.com/2013/10/19/feeling-the-heat-temperature-dependence-of-draping-vases/) .  My obvious first attempt to shrink a vase was to repeat the process but starting with a 8.75″ sheet of glass with rounded edges.  The result was a funky, short fat vase that stood 5″ tall.


How about using the 1″ diameter floral draper?  I went with a 6″ square of rose colored transparent glass.  (Yes, I kept decreasing my starting glass size).  That ended up with a 4″ vase with a small 1″ base and rosy’ flames’ creating the sides.

Smaller! Smaller!

Next attempt used a 7″ circle draped over the 2.5″ form.  I played with blue frit on the border and confetti glass pieces to create a tribute to Mondrian.  This ended up more like a bowl than a vase.  Total height = 2″.

Fourth variation really pushed the limits.  Only a 4.5″ circle of glass was draped over the 1″ form.  This resulted in a truly petite 2″ tall vase.  Perhaps this is only good for holding a few Jelly-Bellies?

Here is the final line-up of vase variations.

DSCN1683As you can see, I have a much broader range of vase options than I thought.  I had a blast pushing the limits of down-sizing with this project.  In the end, I must agree with Mies Van der Rohe.  Yes, ‘less is more.’

A Plateful of Knowledge

Learning a new craft can be an arduous process with many false starts before success.  Looking at this recent fused glass platter I made

Plate of Knowledge

one would not know the journey I took to get to this point.  Multiple learning ‘opportunities’ went into the creation of this.

The bane of my early fusing existence is now frozen in the center of this platter.  Yes, for months, a flat rectangular blue piece of glass with white steps mocked me.  This was the very first attempt I made to fuse glass in my new kiln.  The intent – tack fuse white rectangles so they held their shape above a vibrant cobalt blue base.   I actually made two pieces and they looked like this after firing:


Immediate observations – I went to too high a temperature and everything fused into a solid flat piece – no tack fusing.  (Ok, I was learning my kiln’s temperature profile).  Also – you’ll note the edges seem very rough.  This is because I had to basically break the glass off the kiln shelf.  I believed the beginner instruction book that said kiln washing the shelf would be sufficient to prevent glass from sticking.  Ha!  I’ve used shelf paper between my glass and the kiln shelves ever since.  A third observation – the finished glass is very thin.  I should have used 2 layers of 3 mm glass and then added my smaller rectangles.  Glass naturally wants to re-solidify at a certain thickness (~4 mm) and I didn’t provide enough to make the laws of physics happy.

After many months, I decided to revisit my sins and try to make something out of my first fuse attempt.  To make the platter, I used a clear base with an opaque white sheet on top (my 2 layers of 3 mm glass).  I then centered my original blue/white rectangle in the center (3rd layer).  To make a border and add visual interest, I placed 4 strips of cobalt blue near the edges.  My pride with the placement of these blue strips is that they did not cause the outer platter edges to bulge out in any way – another early problem I had when layering smaller components.

Now, every time I look at this platter, I see it as a symbol of what I have learned in these first months glass fusing.  I’m really glad I choose to tackle this demon.

A Scattered Approach to Leftovers – Making the most of scrap glass

It happens to the best of us – the accumulation of little bits of glass.  Too big to throw out but not great enough to make it into an official art piece.  Soon, plastic bins are bulging with these discards.  How to alleviate the guilt?  Make more fused glass!

These scattered glass pieces are some of my favorites and are almost ‘free’ since they are composed entirely of scrap glass.

DSCN1464   Assemble some scraps.  Be sure to include a lot of clear glass.  This example uses opaque glass but it is even better layering transparents.  Freely snip pieces into irregular shapes.

Don’t cut a glass base.  We are going to be creating a piece with holes.

Do have an outline drawn on kiln paper or a general shape in mind as you begin to lay out pieces.  Start on the outside and work towards the center.


Leave lot of space.  Then add another layer of glass pieces – creating bridges between other pieces.


Continuing stacking and layering.  Remember to use lots of clear!

In general, it is ideal to have 3 layers of glass in the overall stack.  A few places could have up to 4 pieces but don’t overdo it.





Here’s the final raw piece and what it looks like after a full fuse.





Now slump into a mold.  This one is a 8″ bowl.  You can also try plates and platters, etc.

DSCN1482Now there is no excuse to throw out glass scraps bigger than 1/2-1″!  The best use of leftovers ever.

Feeling the Heat – Temperature Dependence of Draping Vases

One of my first exposures to fusing glass involved a very simple class where we selected 1 sheet of glass, cleaned it, figured out the center, and placed it over a form in the kiln.  The instructor worked some kiln magic and after several hours invited us to peer into the kiln to see how the flat sheet of glass had begun to fall around the form.  (This is technically draping and not slumping glass).DSCN1437

How cool!  Was it really that easy to make beautiful glass vases?  I didn’t know enough to realize what factors played a role in creating the magical whimsical handkerchief forms.  Nevertheless, like a junkie’s first hit, I was hooked.

Yes, the instructor muttered under her breath about the danger of over-firing the glass and actually getting the mold stuck within the glass and having to destroy the glass and even the mold but who was listening?  This post will not auger into disaster scenarios, though.  (There is plenty of time for examples later…).

With time, I have begun to see the versatility possible with creating vases.  Obviously one can fuse many pieces together to create a 2D sheet that is far more complex and exciting than a single color sheet of glass like I was first exposed to.  Another Boulder artist, Bobbi Vischi (www.bobbivischi.com), takes this to an awesome level.

The key to the final shape all comes down to temperature.   I have conducted a experiment creating vases that have been taken to different slump temperatures.  Remember, glass most soften and begin to melt.  The amount the glass ‘melts’ is temperature dependent.  The glass will first seem to fold along one axis creating what is affectionately known as a ‘taco’ (or is it because this always seems to occur at lunch time during classes?).  As the temperature is increased, the glass moves more and additional folds are created.  At higher temps, the glass really begins to take on the form of mold it is draping over.  Go much further and you are risking it all.

‘Don’t forget time!’ you may say but that seems almost secondary to the ultimate heat the glass is exposed to.  At low temperatures, even if I hold for an extended period of time, I can’t seem to move much beyond the taco shape.

Pictures tell the story the best.  In all cases, the kiln firing schedule was as follows:

Ramp     150F/hr     to 300F          and Hold for 15 minutes

Ramp     300F/hr     to 1100F        and Hold for 20 minutes

Ramp     150F/hr     to SLUMP TEMP     and Hold for X minutes

Cool       400F/hr     to 950F          and Hold for 1 hour

Cool         150F/hr     to 800          and Hold for 10 minutes

Example 1:  1175F for 1 min (Hit Taco shape at 1100F)DSCN1426Example 2:  1200F for 1 min


               Example 3:  1225F for 1 min (about as far as want to go)


Now back to experimenting with my vases….