Apparently you CAN blow glass in a fusing kiln.....

Zeldazog · March 11, 2009, 11:19:20 PM

Not sure if this i the right place to put this but here goes....

As part of my current uni project, I am investigating methods of applying the same surface decoration to ceramics and glass, in this case, bas relief techniques.

I have been taking casts of objects in plaster, as well as carving patterns into plain plaster blocks. I have then slip cast some tiles in white earthenware before slumping (float) glass at higher temperatures to pick up all surface detail - kiln carving.

I've done loads which have produced varying and some interesting results (specially when I make photograms of the glass) - this one went somewhat wrong:

GLASS BUBBLE

I don't know if there was something the plaster (it was certainly dry as this is the second firing of the block) or something stuck on the surface of the glass that created a gas as it burnt off, and couldn't escape. Whatever it was, I doubt I could repeat it - but I do like it, even if I have no clue what to do with it!

The link is just to the image, if you (really) want to read the rest of the blog, click here.

Black Heart Beads · March 11, 2009, 11:43:44 PM

WOW that is some bubble.

Stacy · March 12, 2009, 06:50:28 AM

I really love that... Flatten the bottom, turn it on its end and fill it with lampwork beads, or sweets, or biscuits...

Or leave it that way up and fill it with unfelted bright merino strands and have it as a colourful ornament... or what about painting it with glass paints and riging up a light bulb on flat surface and using it as a lamp!!!

Oh I really love it!!!!!

Pat from Canvey · March 12, 2009, 07:25:28 AM

Instead of glass paints, you could apply glass globs with UV glue on the underside and put a little revolving light inside to get a disco light.

Pat from Canvey · March 12, 2009, 07:32:52 AM

Afterthought, Were you using kiln wash and if so, was it completely dry. There may have been some residual dampness in the bottom of the dots.

Les · March 12, 2009, 07:33:42 AM

You could hang it, like a hanging basket, in your window and fill it will all sorts of beads and bits of glass... it'd look lovely when the sun shines through it

Dizzy Di · March 12, 2009, 08:03:58 AM

Hi,
You can get bubbles smaller one's with baking soda in between 2 pieces off glass (I have been told), I have not tryed this yet, I bought back from the states last year a product called bubble, thats a fine white powder.
On the other hand, how about painting with stained glass stains can it be painted from the inside, like the japaneese do? and putting a light underneath, ikea had a shelf a few years ago that lit up it would look good on that.
Good luck with uni and thanks for the hint of carving out plaster I am on city and guilds for kiln formed stained glass and working with lost wax at the moment. now off to carve hand shape out of casing plaster.
Dianne

Stacy · March 12, 2009, 08:30:12 AM

I forgot to ask: What the's course you are doing?

theflyingbedstead · March 12, 2009, 09:33:59 AM

A curious thing! What a shame you've poked a hole in it though. Can you re-use the mould again and try to recreate the effect? Did you wash the glass before the firing...maybe it was still a bit damp when it was placed on the block? I presume there was a tight seal around the edges of the glass and block, with some air trapped in the holes and the middle, which then expanded an amazing amount during firing.

Zeldazog · March 12, 2009, 08:33:25 PM

Quote from: Pat from Canvey on March 12, 2009, 07:32:52 AM
Afterthought, Were you using kiln wash and if so, was it completely dry. There may have been some residual dampness in the bottom of the dots.

No, Pat, no kiln wash, they are plaster/flint blocks, so no wash required, and it was second firing of the block itself, the shelf hadn't been washed in the last couple of firings either.

The first piece of glass I fired on it had a raised bump too, which is why I wonder if it was someting on the glass, rather than the block, as I would have expected the result to lessen as it burnt off, not increase!

Zeldazog · March 12, 2009, 08:36:09 PM

Quote from: Les on March 12, 2009, 07:33:42 AM
You could hang it, like a hanging basket, in your window and fill it will all sorts of beads and bits of glass... it'd look lovely when the sun shines through it

Lovely idea Les, unfortunately it has stretched so much that it was super thin at the peak of the bubble, so much so it flexed and broke (that was after a gentle poke, but it wouldnt' have taken any weight).

Zeldazog · March 12, 2009, 08:43:31 PM

Quote from: Dizzy Di on March 12, 2009, 08:03:58 AM
Hi,
You can get bubbles smaller one's with baking soda in between 2 pieces off glass (I have been told), I have not tryed this yet, I bought back from the states last year a product called bubble, thats a fine white powder.
On the other hand, how about painting with stained glass stains can it be painted from the inside, like the japaneese do? and putting a light underneath, ikea had a shelf a few years ago that lit up it would look good on that.
Good luck with uni and thanks for the hint of carving out plaster I am on city and guilds for kiln formed stained glass and working with lost wax at the moment. now off to carve hand shape out of casing plaster.
Dianne

I've tried the bubbles with baking soda - somewhat unpredictable! But they tend to be lots of little bubbles.

You really should have half flint mixed in with your plaster Dianne, it certainly won't survive more than one firing - I haven't had a problem using a plaster block without flint in it, other than it being a crumbly mass after firing, I suppose that might depend on temp you take it to.

Zeldazog · March 12, 2009, 08:46:42 PM

Quote from: theflyingbedstead on March 12, 2009, 09:33:59 AM
A curious thing! What a shame you've poked a hole in it though. Can you re-use the mould again and try to recreate the effect? Did you wash the glass before the firing...maybe it was still a bit damp when it was placed on the block? I presume there was a tight seal around the edges of the glass and block, with some air trapped in the holes and the middle, which then expanded an amazing amount during firing.

I am not sure if the mould will survive one more firing - but it was a dead easy design, it was simply a flat plaster block with a pointy proddy tool poked into the surface as dotted lines.

I am sure the glass was dry, and yes, my only conclusion is that it managed to seal to create such a bubble.

Zeldazog · March 12, 2009, 08:47:47 PM

Quote from: Stacy on March 12, 2009, 08:30:12 AM
I forgot to ask: What the's course you are doing?

I am doing a BA (Hons) in Crafts - go on, ask me what that means...... (I told someone tonight at Tai Chi and she simply went "oh" as in "is that all, that's not a proper course" - she didn't say that , it was in her voice though!)

Les · March 12, 2009, 09:12:36 PM

Quote from: Zeldazog on March 12, 2009, 08:36:09 PM
Quote from: Les on March 12, 2009, 07:33:42 AM
You could hang it, like a hanging basket, in your window and fill it will all sorts of beads and bits of glass... it'd look lovely when the sun shines through it

Lovely idea Les, unfortunately it has stretched so much that it was super thin at the peak of the bubble, so much so it flexed and broke (that was after a gentle poke, but it wouldnt' have taken any weight).

aww... shame