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rakukuku    122

Steven Branfman (sp?)  puts glass into the outside of thrown pieces and then raku's them.  He tells how in his book on raku. cool stuff.   rakuku

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Stephen    139

I would strongly recommend contacting the art glass companies b4 using on anything other than Raku and even then adjust how I used it. I have been told their glass is not compatible and even though it may appear to fit it is likely to fail over time and of course if its in any type of utility use that could/would be dangerous. 

 

I don't usually get caught up in these debates but since the glass companies themselves advise against it even though they stand the most to gain convinces me to listen. I would hate for something I made cause someone a problem or even harm down the road.

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florence w    12

After experimenting with various types of stained glass in the bottom of small heart shaped ring keepers dishes, I've found that many times the glaze under the glass would off gas and cause a bubble or black round spot but no glass on that black spot and/or around the edge of the glass there would be a black ring.  Both very unsightly to my eye.  Recently I've had better results by waxing the area were I want glass, glaze the piece, clean up the waxed area, crush the glass* (or not) being careful to estimate how much glass would cover the wax but not the glazed area.  I have also found that using clear colored glass is preferable to using a glass with mixed colors as the mixed colored glass turn muddy after melting.  The best glass colors I've used are blue or green.  Red glass usually turns an ugly brown.  I've had the best luck using Standard 181 clay or Little Loafers.  All the glazes are made in the studio.  The studio fires to cone 6 with no deviation from that schedule.  I'm most pleased with the glass when it crackles.  Hope this helps.  Experiment and repeat!

 

*Glass crushers are available on stained glass supply web sites or make one using various sizes of metal pipe and end caps to crush the glass inside the largest capped pipe with the smaller capped pipe hammering down the glass inside.  Please do wear eye protection! 

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potterbeth    8

A number of my students have experimented with adding glass to their work at cone 6 electric.

 

First, unless you are firing to VERY low cones, most common glass will melt entirely and flow to the lowest point it can reach. Experiment only on the interiors of test pots first...unless you want to replace kiln shelves for the studio....

 

Second, less is often more. Experiment by beginning with small quantities of glass (just enough to cover the bottom of a piece), then increase to gauge results.

 

Third, real glass beads from the craft store are another source to explore. But they are very light and roll around. If you use glass that can roll, it is helpful to glue it in place to make it easier for the person loading the kiln. Just regular glue, like Elmer's, which will burn off long before anything starts melting...not an option to hold the glass where you want it for the entire firing.

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Stephen    139

But even though all looks like it works perfectly and u love the effect, according to at least one large art glass company it will very likely separate eventually. I was told the properties of art glass and pottery clay are not compatible and fusing the two will not work long term and they strongly recommend against it.

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Working with glass slumping/fusing and working with clay, while involving the same equipment and certain principles, are actually 2 different skill sets.

Glass begins to melt and move at MUCH lower temperatures than glazes and clay do. Think cone 018 and lower. Plus it needs to be eased through more phase changes, both when going up in temperature and back down to remain a true glass. If people are taking glass up to cone 6, or even 06, the glass is wildly overtired. Also, unless you are programming some specific ramp holds on the way down, it's not annealed properly either. This is what will cause the shivering off, colour changes in series 96 stained glass, and all that bubbling.

If you want glass/pottery combinations to be lasting, I would suggest doing the glass fusing as a third firing on glazed pottery, or a second firing onto clay fired to maturity. I strongly advocate looking up proper heating and annealing cycles for glass slumping.

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LinR    10

I've used green, clear, brown and blue bottle glass in the bottom of small dishes which are then clearly marked NOT FOR FOOD!  The glass will craze and bubble and sometimes if it is too thick it will split the pot.  So it is fun for decorative pieces but not for functional.  You can use glass on the outside of a piece.  Small shards of coloured glass impressed into the clay will survive the bisque and will run down the outside of a cone 6 piece.  Make sure that the shards are close to the top or you will have glass on your shelves

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cf66    0

Hi all, 

 

Does anyone know if it would be at all possible to fill into cracks with glass? Think Kintsugi,, sort of...

I would like to try filling into tension cracks in some "failed" cone 6 pieces with glass.

Anybody?

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Chilly    329

Hi all, 

 

Does anyone know if it would be at all possible to fill into cracks with glass? Think Kintsugi,, sort of...

I would like to try filling into tension cracks in some "failed" cone 6 pieces with glass.

Anybody?

 

Everything I've read about mixing clay and glass tells me not to try it.  They are not compatible, the glass will fail and produce sharp shards.  Maybe not today or tomorrow, but eventually.  Why risk it?

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Bioman    6

Use a COE glass marked 90 or 96; but do not mix; use one or the other.  These are treated so they won’t get cloudy as regular glass can when it cools post melting.  Glass will flow somewhere above 1400 Fahrenheit.  The bottom of a vessel would contain it; placing a piece on the side and gravity could make a mess of things.  It may or may not be important in this context but glass is normally held at around 950 on the way down to anneal for 30 minutes to reduce stress.  I have seen it done with interesting outcomes.  Just make sure your shelves are primed heavily in case of drips.

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rayaldridge    276

I've fused stained glass to porcelain for many years.  Much of the advice above is accurate.  Don't use too much, crush or cut the glass into small chunks-- quarter inch or so.  Use only in low horizontal spots where the glass cannot overflow.  Do not use in culinary pieces, because the glass will craze violently.  This is a very pretty look on stuff that will not be used with food.  I've done a lot of porcelain paperweights, for example, with stained glass wells.  The glass will not separate from the porcelain, unless it is too thick.

 

Some of the traditional SE potteries used chunks of glass on the shoulders of big crocks and bottles, but remember that these pieces are fired in big wood kilns with wadding to separate pot and shelf.

 

I used glass in some early pipe bowls, as a moat around the bowl:

 

post-65900-0-57761800-1455662344_thumb.jpgpost-65900-0-99433500-1455662344_thumb.jpg

post-65900-0-57761800-1455662344_thumb.jpg

post-65900-0-99433500-1455662344_thumb.jpg

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AndreaB    23

I've melted glass marbles into some of my work. Mainly to cover cracks. As LinR says the glass will craze but that gives it more interest, I think. I place the marble into the center of the piece then retire along with other pieces to be glazed. I haven't fired separately since firing one or two pieces on their own is a waste of electricity.

 

Attached are pics of the finished pieces.

 

post-65376-0-34011700-1455684034_thumb.jpegpost-65376-0-85096900-1455684062_thumb.jpegpost-65376-0-09016700-1455684080_thumb.jpeg

post-65376-0-34011700-1455684034_thumb.jpeg

post-65376-0-85096900-1455684062_thumb.jpeg

post-65376-0-09016700-1455684080_thumb.jpeg

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