What is a kiln's thermocouple?

by Glass Fusing Made Easy

http://www.glass-fusing-made-easy.com/

A thermocouple is the twisted soldered metal pieces on the end of a pyrometer.

It is a temperature sensor used to measure the heat of the air inside a kiln.

It is placed inside the kiln either through a pre-drilled hole for this purpose or through the peep hole.

This device consists of two different metals.

These are joined together at one end, and that end is placed inside the kiln.

When the connection of the two metals is heated a voltage is produced.

The voltage is measured and converted to a temperature reading.

This reading is then displayed on the readable face of the pyrometer. 

For the best results on your reading, always leave about one inch of room around this twisted soldered metal.

Placing it closer to your shelf or glass can cause the temperature to read inaccurately.

Do not allow the wires touch any live heating element wire.

These devices can be used over a wide range of temperatures.

From the vast changes in temperature, this piece can be come brittle.

Try to avoid hitting it when inserting objects inside the kiln.

Although small, they are very inexpensive, hardy and consistent devices.

Time and high temperatures will cause these to wear over time.

If it appears corroded or crusty, it may be time to replace the piece.

They are also interchangeable and have standard connectors, which makes them simple and inexpensive to replace.
Changing this device when it has failed or become corroded can make a large difference in the accuracy of your firings.

Nice, short video of creating a fused glass lamp

Today I thought I'd share this video from reflectionlabs.com on YouTube Fused glass sunflower lamp, it shows someone creating a fun fused glass sunflower ceiling lamp.  The video highlights how the artist cut out the glass shapes and prepared the piece before fusing.  What a great idea!   Many thanks to reflectionlabs for sharing this video.  
Fused glass sunflower lamp

Bullseye reactive glass chart for fusing A MUST HAVE FOR ALL HOT GLASS ARTISTS

We had the old chart on our page until we noticed that Bullseye updated their chart and our page no long worked!  Now you will need to follow this link to get to the Bullseye page and their extensive chart!  Click here to see the chart.

Lost Wax Casting info from Warmglass.com

I came across this nice lost wax tutorial and thought I would re post it on my blog since it is excellent reference info.

THE LOST WAX CASTING PROCESS

The lost wax casting method involves making a wax model, investing it in a mold, and then melting the wax out of the mold to form a cavity into which a glass replica can be cast.

Wax models can be made in several ways, ranging from hand modeling with beeswax or a similar easily molded wax to casting from a latex or other master mold. Wax can be poured into a pan to form sheets which can then be cut and formed.

Regardless of the method used, the creation of the wax model is the first step to using the lost wax process. Once this model has been made, it should be encased in the investment material (usually a plaster/silica mixture).

Once the investment dries, the wax should be removed from the model by inverting the mold over a pan of water and heating it to about 225 degrees F. The wax will drip out into the pan. Be careful not to heat much above this temperature and don't allow all of the water to evaporate. Since wax is flammable, it can catch fire if it is allowed to get too hot.

After the wax has been melted out, the mold is ready to be cured and fired as described in the main body of this chapter. As the glass pieces melt in the mold, they will fill the spaces once occupied by the wax, a process that gives this technique its name.

With careful reclaiming, the wax can be used again in a later project.

Lampworking, in the beginning....

, oxygen concentrator, propane, safety, stringer, torch

So today I thought I'd post a picture of my lampworking area - for fun.  As you can see, it is pretty messy.  I usually keep the glass rods that I am currently using, right in front of me on my work bench.  This isn't always the best thing to do, occasionally a piece of hot glass will pop off a glass rod that I'm using and "stick" on a cold rod sitting in front of me.   

My torch is a Nortel Minor Burner, as you can see in the picture.  I use propane and an oxygen concentrator for fuel.  There are many different types of torches and a few different types of fuels.  Next week I'll blog about some torches available for lampworkers.  

I also like to use frit (ground up chunks of glass) and I keep it close to me on my bench.  I don't have a graphite torch marver attached to my torch, something a lot of glass artists use.  But I do have a piece of graphite next to my torch.  And I use it for a lot of things, like putting frit on it.  

I have a metal work surface laying on my workbench for safety.  I have a lot of small burns around my workbench where hot glass has scorched the work surface.  The metal work surface is laying in the area where most of my hot glass flies when it "pops" off a rod,  which occasionally happens to me.

Also for anyone reading this blog that has no idea how people make glass beads, the glass rod is what most lampworkers use to make beads.  Some people do use thin strips of other glass, like stained glass to make beads.  I haven't ever tried doing it that way even though I have a lot of stained glass.  Glass rod can be purchased in various sizes, the larger diameter rod is the hardest for me to use.  Also very thin glass pieces, which we call stringer can be pulled from the tip of a molten glass rod by using tweezers or pliers--or stringer can be bought.  Stringer is then used by lampworkers to decorate glass beads with dots and lines.  Some glass rods melt easier than others too, but easier melting glass isn't always good!  It can be difficult to work with.  Plus, I have found that certain colors melt easier than other colors!   

Basically a lampworker gradually heats up the glass rod in the flame of the torch, until it is molten, and from there they begin to create a bead by wrapping the glass around a mandrel (something else I will explain later)!  P.S.  I am totally self taught.  I have learned all I know about making beads from reading books and researching online.

This wonderful video is showing how to make lampwork glass door knobs and a ring.  The artist used boro glass to make these.

Lampworking Kiln Critiques

OK Bear, I think you need to give readers a little more kiln information so that they understand what you are talking about!  You think you know it all but...  I don't think so.  

I've been doing some looking around on the internet and I found a lot of  basic kiln critiques, made by kiln owners,  that you didn't mention or even suggest.   This information could be helpful to lampworkers who are thinking about purchasing a kiln.  Hmmmm, I'm wondering what you are doing, Bear?  I guess it just proves that you can put lipstick on a dog, but you'll still get a dog!  

Below are some postings I've found that might be useful for lampworkers.  I'm still working on finding good information on fusing kilns.

"Check into the Skutt GM-10 with a bead door. I've had mine for about 5 years and still think it's great. It has enough flexibility to allow for you to take on new stuff as your glass addiction tackes hold and you want to expand your range."

"I love my Blue Bird.  I also have a jen-ken for fusing. I'd recommend either one!"

"I have the Skutt bead kiln and I love it. It's easy to program and it hasn't had any problems in the 7 years I've had it. I bought it for fusing because it works on 110 and I knew I'd dabble in lampwork (little did I know...). Because it's firebrick, I just turn it off after annealing, rather than ramping down when I make small beads."

"I want to purchase another kiln for bead making. I already have a Jen Ken and after 1 1/2 years I already need a new part. Thank goodness it is covered under warranty."

"If I could do it all over again or get a second kiln, I'd be all over the Glass Hive Wide Guy. I'd sell my Skutt to get it, but the hassle of the sale and shipping is a great deterrent."

"Why the Wide Guy, you ask? Because it's wide and the volume of beads that can be made/annealed at one time would be such a huge plus for me. My Skutt is a greatkiln, but the interior is small-ish for lampworking. Something I just didn't think about when I was researching kilns. My time gets sucked away so easily that when I have a chunk of torch time, I want to make the most of it. The Wide Guy would allow me that freedom to torch for so much longer and make the most of my time. Okay, I have to go look at the pictures of it again *Sigh*"

"Take a look at the Arrow Springs kilns. I have never had one have a failing part and I've been using mine since 1994 (or was it '95?) They are meticulously constructed by someone whose business is beadmakers and they care about what they sell to us."

"I am a Crowley kiln convert. I just love the tall double doors and ease of use."

"I would save up until you can get one with that is brick lined. I just learned how to fuse and also do PMC. I have a chili pepper and I can't use it to fuse or do PMC."

"Many that have an AIM 84BD are pleased with its versatility in being able to anneal beads or do small fusing/slumping projects."

"... for lampworking, I got the Paragon SC2 kiln with bead door and love it. I have a kiln shelf to do quick fuses of small things (trial pendants) and PMC - it can do enameling and small ceramics but I haven't gotten into that yet."

"I LOVE Paragon! I currently have the Bluebird and had the Caldera. They're both great kilns and the Caldera can do fusing and ceramics in addition to bead annealing."

"Digital controllers are expensive and there's more different value in makes of controllers than in makes of kilns. All kilns are basically the same - a brick box with big heating elements. Any difference in value would be in extra features provided - not in different makes. Personal preference between makes of kilns is like personal preference between Chev or Ford. The best kiln to buy is usually the one that costs the least or provides the features that provide the most benefits.

When selecting a kiln, you should pay attention to the size, the features, and the cost. Make is irrelevant. Make a list of what you want, then shop for the cheapestkiln that satisfies your wants.

Having a controller is valuable but not essential. If you're on a tight budget, you can start with a kiln using a pyrometer and add a controller later."

Lampwork kiln

Hey Carol, after reading your COE post yesterday, I think you need to show readers what a kiln looks like.  A lot of people have no idea what you are talking about and need some more information!  I hope you don't intend to use your own kiln pictures, your work area looks like a tornado hit it.

 Thanks Bear for that excellent suggestion!   Unfortunately I only have pictures of my own studio.   And I must admit, it does look like a tornado hit my work area.  But that's because I actually work there!   The top picture is a view of my kiln from the side.  The bottom picture shows the bead door open with some of my beads sitting inside the kiln on my bead holder.

Above are pictures of my "small" kiln.  It is a Skutt kiln that has a bead door on it.  I also have a regular door which I can use when fusing small items.  I like to use the regular door on the kiln for fusing so that way I can control the temperature of the kiln easily.  When the bead door is on the kiln, there is a slight gap around where the small bead opening closes.  A bead door is essential if this kiln is going to be used for lampworking.  Lampworking is just another name for beadmaking, if you are confused.

There are a few kilns made specifically for lampworking.  I owned my kiln before I began lampworking.  If a glass artist wants to use a kiln for more than just lampworking, I suggest they purchase a kiln more like the one I own.  

I have heard about kilns, (or a kiln pot),  that can be used in a microwave oven!  Unfortunately I have also heard that they are difficult to use.  Plus it is advised to use that microwave only for glass and not food, too!  I think it would be a better investment to purchase a regular kiln as opposed to the microwave varieties.