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Showing FAQs 58of 58    


A liquor storeowner gave me his French champagne display bottles for glass slumping. I am having trouble removing the labels. Any suggestions?

Soak the bottles in hot water until the labels loosen. Then scrape off with a safety razor blade (the type available from paint supply stores).

And a suggestion from Karen Hardy of Redondo Beach, California: “I have a suggestion for removing ... [More]

Can an imperfection in the kiln shelf cause bubbles in glass fusing?

Yes. A warped shelf can cause bubbles, because the air in the low area of the shelf will expand during firing. If the air is trapped, it will try to escape from under the glass by forming a bubble. Lay a straight edge across the surface of the shelf, ... [More]

Can I fire glass on the soft shelf that comes with the SC-2 kiln?

The soft ceramic fiber shelf is used to support silver clay pieces. The shelf is not suitable for firing glass or ceramics. Nor should it be coated with glass separator. To fire ceramics or glass, please order the hard ceramic shelf.

... [More]

Can the shelf inside a glass kiln be placed directly on the firebrick bottom?

Because the kiln shelf is a heavy thermal mass, it takes longer to heat up than the air around it and the glass on top of it. Placing the shelf directly on the kiln bottom makes the shelf more difficult to heat. This is why we recommend placing 1/2” ... [More]

Can you fire glass in a ceramic kiln?

You can fire glass in a ceramic kiln, but it may require experimentation.

The first time we fired glass in a fusing seminar at Paragon, we used an 8-sided ceramic kiln with Kiln Sitter shutoff. The pieces turned out quite well.

He ... [More]

Can you fire two or more shelves in the GL-24 series glass kilns?

The GL-24 series kilns are not designed for multiple shelves of glass. If you fired two shelves slowly, the bottom shelf would reach a low fuse and the top shelf a higher fuse.

... [More]

Can you slump more than one bottle at a time in a kiln?

Yes, you can load more than one bottle per kiln shelf. The bottles should be spaced far enough apart so that when they slump, they will not touch each other. Before firing a kiln load of bottles, experiment with one or two to make sure they will turn ... [More]

Can you tell me how to get kiln shelf primer off of molds? I've scrubbed and scraped, but it's still on there.

You don't have to get it all off. If it won't come off by scrubbing, it won't flake off during firing, either. Don’t worry about the residue that remains as long as the surface is smooth enough to add a fresh coat.

... [More]

Could the Kiln Sitter be used as an over-temperature safety shutoff for glass firings?

Yes. The Kiln Sitter uses a pyrometric cone to sense when to shut off the kiln. Use a cone that is rated to a higher temperature than the glass yet lower than the kiln's maximum temperature. If the kiln ever begins to overfire, the cone will bend, an ... [More]

Do you recommend didymium glasses for viewing the kiln interior?

Paragon's kiln safety glasses are green #3. The manufacturers of safety glasses do not recommend didymium glasses for viewing the hot kiln interior.

... [More]

Does a glass kiln need a motorized vent?

You probably don’t need a downdraft kiln vent if you fire only glass. But the vent is desirable if you fire fiber paper and glass paints.

... [More]

Does a switch-operated glass kiln require constant attention?

If you are firing simple, small projects, you won't have to spend much time watching the kiln. Write down how long it takes for the kiln to turn red-orange inside. Begin watching the glass (either through a peephole or by lifting the lid an inch) at ... [More]

How can you tell which side of clear dichroic glass is up?

As you assemble the glass pieces, it is easy to tell which side of dichroic is up when you know the trick: Look for the shadow at the edge of the glass. The coated side will have no shadow. With the uncoated base side up, the edges of the glass will ... [More]

How closely should one follow published or recommended glass firing schedules?

Never hesitate to change a firing schedule. For instance, if you want the glass to fire hotter, feel free to raise the temperature. A firing schedule is only a guideline. Since every kiln fires a little differently, results may vary from one kiln to ... [More]

How do you apply glass separator to the shelf or mold?

Glass is fired on a kiln shelf and not directly on the kiln bottom. You can also slump glass over a mold. The kiln shelf and sagging mold must be coated with glass separator to keep the glass from sticking to them. Glass separator is similar to kiln ... [More]

How do you apply kiln wash or glass separator to stainless steel molds such as a bowl? For me, the coating falls off.

Heat the stainless steel mold to 250 degrees F in your kiln, in an oven, or with a hair blow dryer. Then spray on the glass separator using an airbrush or even an inexpensive pesticide sprayer available from a building supply store. Shake the glass s ... [More]

How do you avoid glass bubbles?

Bubbles in hot glass are usually caused by trapped air between the glass and the kiln shelf or between layers of glass. Here are several ways that air can become trapped:

1) The kiln shelf absorbs moisture from glass separator (the coating ap ... [More]

How do you fuse glass in a digital kiln when you don’t have a firing schedule?

These general guidelines explain how to fuse glass in a digital kiln. You will likely need to alter the firing schedule for your kiln and brand of glass.

The basic firing schedule:

Alarm 500°F

Segment 1: rate 300°F to 750°F ... [More]

How do you know when the glass has finished fusing?

Fusing glass is a visual process. When you load the kiln, position the glass so that you can see it when you look through the kiln's peephole. Look at the glass occasionally during firing.

When looking at hot glass, please be sure to wear f ... [More]

How do you prevent fused glass from cracking?

Most problems in fusing are caused by rushing the firing. The glass must heat slowly during the critical temperature range of 100 – 500 degrees F.

The second critical temperature range is annealing, which is the cooling range of 950 – 750 deg ... [More]

How do you prevent the glass separator from sticking to the glass?

A coat of glass separator will usually last several firings. The lower the fusing temperature, the more firings you can get from one application of separator.

If the glass separator is sticking to the glass, fire to a lower temperature. Are ... [More]

How do you remove kiln wash from the back of fused glass?

Try soaking the glass in vinegar overnight.

... [More]

How do you slump glass bottles in a ceramic kiln?

Most kilns can slump glass bottles. Wine bottles are a fairly easy project. You don't have to worry about glass compatibility, since you are not fusing different glasses together. (If different types of glasses are fused together, they must be compat ... [More]

How do you slump glass using the QuikFire and PCB-1 control?

1) Insert the project into the QuikFire. Place the muffle over the project. Prop the muffle with a 1/2” or 1” post.

2) Plug the QuikFire into the PCB-1 control box. Plug the PCB-1 into the wall outlet.

3) Turn the QuikFire switch to ... [More]

How do you smoothen the glass separator?

Give the shelf two or three thin coats of glass separator, changing the direction of the brush stroke each time. Apply the separator with a haik brush. After the separator has dried and the shelf is cool, you can smoothen the separator by rubbing you ... [More]

How do you test glass for compatibility?

1) To test glass for compatibility, fuse half-inch square sample pieces of different glasses onto a larger base piece of clear transparent. It should extend beyond the small sample pieces by half an inch on each side. One of the sample pieces should ... [More]

How does one cut glass circles and curves?

Do not press too hard with the glass cutter, which is a common error. It also helps to use a high quality reservoir cutter.

After cutting a circle, make cut lines that radiate out from the circle to the edges of the glass. Then break off the ... [More]

How fast can you fire small glass pendants?

Small glass projects such as a 3/4" x 1 1/2" pendant can ordinarily be fired as fast as the kiln will go and without controlled cooling through the annealing range. For instance, Paragon's small QuikFire will reach 1000 degrees F in five minutes. Tha ... [More]

How I can retain a glass hole while fusing? Drilling a hole in the glass after it is fused results in rough edges.

There are two ways to make a hole in glass:

1) Insert fiber paper between pieces of glass. After you have fused the glass, clean out the fiber paper. It will leave a void in the glass for stringing a chain.

2) Arrange the glass so t ... [More]

How often should glass separator be applied to the shelf?

You do not need to re-apply glass separator to the shelf until you can see cracks and flakes in the glass separator. If you fire to medium fuse instead of a flat fuse, you can usually get many firings out of one application of glass separator. You sh ... [More]

I dutifully scrape and reprime my kiln shelf each time I fire glass higher than 1300 degrees F (704 degrees C). Is that really necessary?

It depends on the temperature of your firings. If you fire to a full fuse, reapply fresh kiln wash (also called shelf primer) after every firing. If you tack fuse, reapply kiln wash only when the old coating has flaked off.

... [More]

I have a new Paragon glass kiln with element in the firebrick lid. Do you recommend a special first firing?

Fire the kiln to 1000°F and hold for 30 minutes with only the shelf and posts inside the kiln.

The element grooves in the firebrick lid are hardened with a refractory coating that helps to prevent brick dusting. As the elements expand during ... [More]

I have recently tried slumping wine bottles in my kiln. After a few days, the bottom cracks off. What am I doing wrong?

It sounds like the bottles cooled too quickly. The thicker the bottle, the slower it has to cool. Bottles are especially prone to cracking if you fire them a second time to add a decal. This is because the glass is fused together and is thicker than ... [More]

In the first fusing classes I took, the store did a tack fuse and a full fuse in one kiln load using multiple kiln shelves. What temperature is required for this technique?

You can do this in a glass kiln that has a fairly deep firing chamber and top elements, such as the GL-24AD. Fire two shelves stacked vertically and separated by posts. The glass on the top shelf will reach full-fuse; the glass on the bottom shelf wi ... [More]

Is firing glass hard on a ceramic kiln?

Most glass projects are easy on a pottery kiln. This is because glass is fused and slumped at low temperatures (1300 - 1500 degrees F). The Type-K thermocouple lasts a long time in that temperature range.

However, very slow heating and cooli ... [More]

Is it okay to use a downdraft vent while firing glass?

It is okay to fire glass with the vent turned on. If you use fiber paper, the vent will be very helpful in removing harsh fumes.

... [More]

Is there a fast way to cut small pieces of glass?

First make all your score lines on the glass. Then turn the glass over and tap out the pieces. This is an easy, fast way to cut many pieces.

... [More]

Is there a way to reuse glass after it’s been fired? A huge bubble has formed in the middle.

Yes, there are many ways to salvage fused glass. Do not throw away a disappointing piece.

You could sliced the glass into 1/4" strips and incorporate them into new projects. Or crush the glass and make coarse frit, which is beautiful when fu ... [More]

Should I kiln wash the bottom of my kiln to anneal beads?

It is not necessary to kiln wash the floor of your firebrick kiln to anneal glass beads. Allow a freshly finished bead to cool slightly before inserting it into your hot kiln. This is to prevent the bead from flattening on one side when it is placed ... [More]

Should silver clay be fired on a separate shelf from glass?

Yes. The silver contamination in the shelf can affect the color of glass.

... [More]

Some of my glass pendants have sharp edges, and some of the design work blended together and lost detail. How do I correct this?

The easiest way to eliminate the sharp points in the pendants is to fire to a lower temperature. That is also the way to retain shadow lines formed by the separate pieces of glass. The higher the fusing temperature, the flatter the glass surface beco ... [More]

What causes a kiln shelf to crack down the center during a glass firing?

You shelf may have cracked down the center due to thermal shock. A heated mass on the center of the shelf can crack the shelf if the kiln is cooled too rapidly. That is why it is a good idea to place small posts between the kiln shelf and a slumping ... [More]

What firing schedule do you recommend glass jewelry in the Paragon QuikFire?

1) Insert pieces. Turn on kiln.

2) At around 1200 degrees F, lift the muffle an inch or so to check the glass. Check it every 30 seconds until the glass edges begin to round. Then check every few seconds.

3) Unplug the kiln when the f ... [More]

What glue works with glass and jewelry findings?

Suggestions from the readers of our Kiln Pointers newsletter:

Elaine Klugesherz of Saint Louis, Missouri wrote, “On the tube of E6000, directions suggest using this product when temperatures are 70 - 85 degrees Fahrenheit, allowing 24 - 72 ho ... [More]

What is COE?

When glass changes temperature, it expands and contracts. The rate at which glass changes size is called the coefficient of thermal expansion. If you fuse two glass pieces together and one changes size faster or slower than the other, the fused piece ... [More]

What is fire polishing?

If you have ground off imperfections from a fused piece of glass, you can sometimes use the kiln to polish the grind marks. Place the glass back inside the kiln and fire it hot enough to just begin rounding the edges again.

... [More]

What is glass slumping?

Glass slumping, or sagging, is the process of heating glass over a mold until the glass softens and sags into the mold. For example, if you heat a round glass shape over a bowl, the glass will take the shape of the bowl at high temperatures.

... [More]

What is the best height for the shelf in the Paragon Fusion-10 glass kiln?

We recommend 1/2" tall posts under the shelf in the Fusion-10. This height aligns the shelf with the side element for even heating. But you should feel free to experiment with shelf height too.

... [More]

What is the difference between kiln wash and glass separator?

Glass separator and kiln wash are finely ground minerals that do not fuse at high temperatures. They serve the same function: to prevent glaze and glass from sticking to the shelf.

The difference between Paragon’s glass separator and kiln was ... [More]

What is the main difference in the procedure for slumping glass in ceramic and stainless steel molds?

Glass is slumped into ceramic molds and draped over stainless steel molds. This is due to the difference in expansion and contraction between the glass and the mold. Glass contracts more than a ceramic mold and less than a stainless steel mold during ... [More]

What method do you recommend for forming a hole in a glass pendant during firing?

Coat a toothpick with glass separator and place between layers of glass. The toothpick will burn out during firing, leaving a channel. You can also use a 1/8” wide strip of ceramic fiber. Remove the fiber with a toothpick after the glass has cooled. ... [More]

What pointers do you have for firing dichroic glass?

Dichroic glass has a bright, reflective surface that can add a dazzling touch to a fused glass piece.

However, I have found that too much dichroic can overpower the basic design. Sometimes a tiny sliver of dichroic glass can add more drama ... [More]

What pyrometric cone do you fire glass to?

Glass fusing temperatures vary depending on the brand of glass and even on the color within the same brand. 1500 deg. F. (cone 013) is typical.

Using cones to fire glass may be a process of trial and error, though. Looking at the glass throug ... [More]

What type of glue do you recommend for glass fusing?

Glass fusing is the process of heating two or more layers of glass to the point where they deform and stick together. In this email, I will share a couple of simple pointers: how to clean and glue the glass before firing.

Grease, dirt, and fi ... [More]

When I'm slumping glass into a mold such as the wine bottle slumper, do I need the kiln shelf under the mold, or can I set the mold directly on stilts?

We recommend the shelf under the mold to protect the kiln from melted glass. If there is no danger from melted glass, you could eliminate the shelf. The mold should be separated from the shelf with short posts or stilts.

... [More]

Why do my glass kilns not fire glass at exactly the same temperature?

The thermocouple measures the temperature inside the kiln. A thermocouple is made of two dissimilar metals welded together at the tip. When the thermocouple is heated, it creates a very small voltage, which the controller converts to a temperature. T ... [More]

Why does my glass kiln have more than one relay?

We have added a second relay to the Fusion-8, Fusion-10, Ovation-10, Pearl-18, and Pearl-22 kilns. If your serial number is higher than 375978, your kiln has two relays. If your serial number is lower, your kiln has one relay. The elements in the new ... [More]

Why does my kiln fire glass slightly too hot?

If the kiln overfires by the same amount every time, lower the programmed temperature by 50 degrees or whatever temperature is necessary to compensate for the overfire.

If the kiln is not firing consistently, check the thermocouple wires. Th ... [More]

Showing FAQs 58of 58    

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