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As I promised in my last article, this article is going to be about what I call thermal indifference assembly, through proper annealing - or TIA for short. I'm sure most of you are sitting out there wondering "what in the hell is Dodson talking about now?"

First of all, let me say that this technique, which I use every day is not mine. I did not invent, create, or claim it in any way, other then I seem to understand it. I've learned it and I use it on a daily basis and it works for me. I don't know the exact history of how this technique of working borosilicate, came to be, but I do know that Ginny Ruffner, Susan Plum, Hans Fräbel, Shane Fero and a number of other people have used varieties of this technique for over 10 years now. So far every one I've seen has pretty much developed their own system and style for this unique technique.

Before I tell you about the technique itself I think its important to tell you a little bit about how I used to work and how I first encountered this technique. For 32 years now I've sat behind a torch in one location or another between 8, 10, 12 hours a day, probably very much like most of you reading this, and made glass items of one kind or another.

My first 22 years in this business I pretty much worked traditionally using a one shot process. I believed and would have argued the fact that with borosilicate glass, which of course then I just simply called Pyrex, you had to sit-down, make your item, and finish it in one step in the fire. Then you would flame anneal it to a point at which it would last forever, however long forever might be. Of course my hopes were that it would last for years, which it didn't always do. As most of you know, borosillicate, just like all other glass, needs proper annealing to relieve the stresses and strains in it. If I were to sit down and make a dragon, I would make the dragon, and I mean every part of that dragon, wings, body, head, detail on the eyes, detail every area in one shot, heat the whole thing up until I think it’s the same temperature, a dull glow of red, and set it down in front of me and let it cool. Although I did go through that one brief phase 25 years ago of burying my work out in the backyard about 2 foot deep in the dirt, which, if you don't have an annealing oven, sort of works OK.

Ok, so what the hell is TIA? I get e-mails just about every day and the number one question I get asked about my big work is (from other lampworkers that don't know how to do it) "how do you keep that much glass hot?" And of course I don't, these big pieces and my average large sculptures weigh anywhere from 4 to 6 lbs. Now to the non-lampworker this probably doesn't sound very impressive, but to anybody who's sat behind a torch and held a punti with a sculpture on the end of it for any length of time, they know right off that 4 to 6 lbs. is a lot of weight! Even my smaller pieces, which weigh 2 to 3 lbs., are extremely strenuous when I'm holding them and working on them hour after hour. It’s a whole lot like when I was a kid, and my Dad held up a little lightweight shoe and said "you think you can hold this out for a minute, if you can, I'll give you a dollar" and I held up the shoe and it weighed almost nothing and I said "yeah" so I bet him the dollar. I must have been about eight and I held my arm out straight and after about 45 seconds I was sweating my butt off and my arm was sore for 2 days. The difficult part about making these big heavy pieces is that the weight on the end of the punti can cause it to fall and break after you've spent hours and hours working on it. By the way the absolute, most dangerous, demon-devil, horrible problem about doing this work is bad punties. If you are going to hold up 3- 6 lbs. of glass make sure you have a good solid joint. Design your piece where you can melt it off without getting into the body of your piece. Never relie on a cold joint.

I first became aware of this kind of work about 11 or 12 years ago at Pilchuk Glass School in Seattle under the tutelage of Jenny Ruffner. I remember real clearly the first time I heard her say what she was going to do, which was totally alien to the way I had worked. I seriously doubted in my mind if it would work, even though I knew Jenny's work and I knew that it held together and it was very very large compared to anything I had made. And then I watched in absolute total amazement as she did exactly what she said she would do.

The process I use is a little bit different because it's evolved over the last 10-12 years, but basically, the concept is this; the problem encountered in making huge, multi component (in other words a lot of pieces) work is putting it together in such a way that it melts and becomes one. I mean all of you know that you start out with one piece of glass and the idea is to wind up with one piece of glass, all you want to do is change the shape of that piece of glass. But on a molecular level, you want that glass to be as undisturbed as possible. When I'm teaching, I use a scenario which is very simplistic, but it seems to be universally understood and drives the point home real well. If, within the piece of glass that you are making, lets say it’s a 1' solid rod of Pyrex glass, all of the molecules are pretty much at rest and that's because its been annealed at the factory and all of the molecules have found a place that they like. Kind of a neighborhood they like to live in. Now lets take one single molecule that's all I think we need to cause a problem. Let's take a single molecule and call it Fred. When you heat up the glass and you make a component, or a shape or a figurine, no matter what you do and how careful you are, you're going to dislodge Fred from his happy little home and move him somewhere he may or may not like to be. Now lets say that Fred winds up next to Suzy and Jill and Aunt Gladys. And Fred just flat hates all three of them. But your piece of glass cools, causing Fred to get stuck in the 'hood he doesn't belong in. And Fred is not a happy camper. Fred wants nothing more then to get the hell out of Dodge. He wants to get out of where he is and go home. But he can't, and that's because when the glass cools the outside of course cools first, due to air hitting it, and it pulls in a little bit, shrinks a little bit and compresses the inside glass and freezes the molecules in the position they are in. Quite often they're not in the most comfortable position. And the end this cute little analogy, is that after the piece is made, cooled and sold to the customer; there are a number of things that can happen, that can give Fred an excuse to bolt. Which means basically that the piece will fly apart, or break, fall apart, sometimes even explode. These things can be anything from a frequency, a snap in cold and hot weather, sitting on top of a piano, or a speaker. There's just hundred's of things that can cause Fred to see the opportunity to get away from these women he don't like.

So the objective is very simple. You want to disrupt Fred as little as possible, and then you want to anneal your piece in such a way that even if Fred was stuck in the wrong place, in the wrong hood, he would still find a place in the annealing process where he was comfortable, along with all the other molecules.

Now in and of itself, that particular piece of information is extremely valuable because even making pieces in one shot production, you still need to anneal them so they won't break and will last a long time. So people won't bring your stuff back to you broke. "Here, fix this, I bought it and it broke." As it so happens, this is where we get to the process of TIA.

Incidentally, there is a phenomenal fringe benefit that goes along with this. And that is, if you do it right, you can make a large piece of glass, whether it be colored glass or clear glass (borosillicate) then anneal it, and then heat it up and add another component, re-anneal it, and repeat the process, again and again. Now this may not sound that important, but I flat could not do what I do without it. I just couldn't. It would also be impossible to do my works without being able to work cold. So what I do is this, I'll figure out basically what it is I'm going to make. I don't tie myself in too tight of a box - and that's another article I intend to write about making these big one of a kind's - concerning making your living making these one of a kind sculptures. First I break the design in to however many components I feel it needs to be. If your gonna work this way you are just going to have to learn this part by trial and error. I cannot count the times in learning this procedure, that I went just a little bit too far time wise, and I lost the whole piece. And all I can tell you is, there is a time limit when your doing this type of work, as far as keeping it out, and keeping it in the fire to make it work. And you're going to have to learn that by touch, by feel. I don't believe there is a way in the world I can tell you what that is. It may even be different for everyone.

So, for instance, I will make the base of a component. And if you look at the picture in the last edition, you'll see how I work in abstract components. As I am making it, if it is really large, say I'm working 1" solid glass, encasing it in color, or larger, anything from 1/2" up, I use the Timework Kiln that Jim Thingwold, publisher for Glass Line, makes and sells. By the way, I should say that without that one piece of equipment my life would be a lot tougher. If you don't buy that one piece of equipment over the next few years (other then my Chem-o-Lene ) you need to buy Jim's guillotine oven. This thing will make your life easier in every way in your shop. Mine is lit from the time I get up in the morning until the time I go to bed at night, and I run a bunch of loads in it. I'll tell you how in just a minute. There is a specific way that I use the kiln that works really, really well in conjunction with a larger annealing oven.

So I have made my first component. Its finished, its glowing hot, I've had it in and out of Jim's oven 2 - 3 times, and it might have taken me an hour, hour and a half to make. It might be about 5-6" tall and as much as an inch thick, sometimes more, and covered in color or clear. So then I go out to my big annealing oven which I keep outside, that I have set to about 475 degrees. Now this is really important, you need to understand the formula, the formula is where this is at. Timing + formula, formula meaning the amount of time that you keep your glass at whatever temperature and how fast you drop it. If you have the ability to set temperatures combined with timing to make a piece properly in the first place, you're going to be able to do amazing things size wize.

I put the piece in my outside oven at about 475 degrees and I come back in and start on another piece. Now the way I work is sometimes I'll start on another piece that will go on that same sculpture, but usually not. Usually I have 2 or 3 sculptures going at any given time, and the reason is because when I finish the second one that I'm working on, I will not be able to attach it using this process to the one that's in the oven because I can't get it out without gloves, and that's not what thermal indifference annealing is about, bringing it out with gloves and attaching it hot at 1000 degrees.

What I do is this, I will make the next component, and setting next to me is a sculpture I was working on last week, yesterday, sometimes last month, sometimes even longer. I work when the mood hits me on a piece. I will pick it up and I will e-a-s-e into it with the flame, at the exact point where I intend to put on the component that I am working on. Sometimes I even put together two cold components but generally it's at the moment I'm finished with the component I'm working on. I pick up the cold sculpture, and I use Jim's oven beside me to keep the component that I'm working on hot, then I e-a-s-e the temperature up of the spot where I am going to attach the component, then I attach it. I e-a-s-e them together using a lot of heat, and a lot of patience, while holding my hands extremely still. Any shaking will cause defitrification and strain, which can be taken care of, (and I will tell you how), but basically you want to be as calm, and as careful as you can. Now this is hard when it comes to the end of a big piece that weighs 3 or 4 lbs. I'm telling you an absolute fact when I say that my whole body is sweating (I live in Texas and I've measured it at a 127 degrees in my shop). I'm here to tell you that after sitting for 45 minutes to an hour with a sculpture that weighs anywhere from 3 to 6 lbs. on the end of a 3/4" or 1" punti, holding it in the air, it is very difficult to put the pieces together in a calm way (I don't like to use rollers). So you have to cheat, and I'm going to tell you in a minute how you're going to cheat.

Once I finish putting the two pieces together and its completely together, I put it back in the oven that's outside at about 475 or 500 degrees, which is tolerable to put my arms in, (it won't burn the hair off my arms or anything) and I come back in and keep working. The oven outside stays at 475 degrees for the entire day, or until its full and I need to run it. The Timework kiln inside is kept at about 1200 degrees, and that way it acts very much like a glory hole. When I stick a piece of glass in it, it doesn't know that its not in the fire, and I can pull it right back out and heat it up and work on it. The big oven and the Timework kiln work very well together. And so on and so on and so on. I will anneal it and I'll talk about the annealing formula I use in a minute, and then I add to it, and I anneal it, and I add to it, and I anneal it, and I add to it until its finished. And quite often that will take me anywhere from 3 days to 6 months. I had one piece (well my favorite piece) that took me almost a year.

Now the cheating I spoke about. When you have two components, and your always going to have two, never try to put more then two components together, it'll fall, it'll break, you'll cry, its sad. So always put together two components, even if one is really big and one is small. The big one is always cold, and the little one is either hot or cold. But we'll discuss hot. When you put this together, generally speaking, as I said, this piece is heavy and I like to keep my work in the air. I'm not one for hand torches. I like the sweat, I like the strain that goes into my piece, it expresses the emotion, it helps me make the piece, and it helps me focus. So I hold it with a punti up in the air, and it is absolutely impossible not to get some devitrification and some strain in the joint when your working heavy. This is where braces come in. Braces are simply glass rods of various millimeter, pick the millimeter according to the job your doing, that are hooked from the part your putting on to the part that you've already made. It is important to try and think of ways as you go along, to have accessible points to be able to add your braces at. You want to make it as discreet as possible. Because the last process I usually do is making sure that all the places the braces went on are completely smooth so you can't tell that anything ever happened there. And if you don't design your piece right you will crack your piece trying to clean those areas up.

The general rule that I follow on how large of a diameter of rod to use for a brace is how big the thing is. I mean if it’s a 6-lb. piece and I'm adding a pound, I'm going to use an 8-millimeter rod for the braces. If it's larger, I'll probably go to 10mm, but I never use bigger than 10mm. Another thing that is extremely important is how well you melt the braces in. When in a hurry, there is a tendency to want to just stick the brace on and continue on. I promise you that brace will release, it will fall, it will break, you will cry. Your braces have to be attached in such a way that you can tap them and they're not going to come off, and they're not going to come off as the two pieces adjust to each other. The strongest points are going to be those braces. I'll put at least 2, and the obvious reason for that is, if one goes you've got one to back you up, to rely on. Usually I use 3. If you can find a place to put three braces, the third one can be even 5 millimeter, but its hard to break 3 braces, they act like bridge supports and play off each other when placed correctly. Then I take the piece by the heaviest, coldest part, I put it in the fire and I get in there in that joint with the big soft fire of my Carlisle, with the pointy little center fire really blasting, and I melt the two together with the ease and the comfort and the time that I would never have if I were trying to hold each side with both hands. In fact, I can usually hold it in the fire and do all of my work with one hand as I adjust the knobs, or change the TV with the remote in my other hand, of course that's more of a Texas thing.

This is another extremely important thing if you're going to do this. The first step when your melting it is just blasting that whole area where the two go together until you see the lines where they go together disappear and you see it start to flow together. Then you have to let it cool because it will get away from you if you don't. This normally leads to devitrification on the surface all the way around, or at least a good portion of the way. To get rid of the devitrification and add strength to the piece, while the braces are still on and the piece is cooling down and has dulled to a very light red glow and certainly has no movement left in it, you come in and heat, with very soft fire, one side of the area that has the devitrification covering the joint. It will melt out, you keep it out of the fire at the very end of the flame, so it just keeps warm, As soon as the side you just worked cools to the point that its not going to move or change, you heat the next section, which is usually the other side. There are times I have to break it into thirds. This gives you a clean, seamless joint, which is very very strong. This is extremely important. Then you take it and put it in the outside oven set at 475 degrees.

So now I have my outside oven filled with sculptures in various states of completion, and its setting at 475 degrees. The reason its set at 475 degrees is very simple, the point at which I have suffered, and where most people suffer most of the cracks in the annealing process, is at about 400 degrees. I have found as long as I keep my work over 400, at 450 to 475, anywhere from there up, it will not break because of the kiln. It may break because of something I did, but it will not crack because of the temperature. Then I run the kiln up to 1095 exactly. And I hold it, or soak it, at that temperature for thirty minutes per thickest half inch of material that I have in the oven. In other words, if the thickest thing I have is a 1/2 inch I soak it for 30 minutes, an inch equals an hour and so on. If I'm making a piece that is 3 inches, I will soak it for as long as it needs, and then I turn the kiln off. The kiln's temperature will drop on its own over a period of about 6 or 7 hours. I have found that that rate, for me, it gives me what I call a dead anneal. Now how do I know that it is a dead anneal? I know because if I take it and stick it in the fire, this 2 - 3 foot tall solid glass sculpture that weighs 6 lbs., doesn't break (although you don't want to do that unless your adding another component). And that brings me to one of the last points which is, if your working large using this TIA process, occasionally, and for me, quite often, you will find something, somewhere that needs polishing out or fixing when you think your done. Usually where I pulled a brace off and forgot to go back in and fire polish.

The rule, and you should always follow this rule (in my opinion), is simple. Every single time that you go into that piece to fix even the smallest thing, when you're done, reanneal the whole thing using the 1095 farenheit at 30 minutes per thickest half-inch rule. I think, although I don't know for sure, yet, that there is no limit to size if you can handle the weight of the glass, as long as you follow these rules correctly.

Now there's another cute little trick that works really well in this process, and I use it for quite a few of my pieces. That is a hot plate. But not an ordinary hot plate. Most hot plates only get to between 400 to 500 degrees. 400 and 500 degrees won't do anything for this process at all. BUT, there are hot plates that are made to get to 1000 degrees. Corning made hot plates for years and years that got to 1000 degrees, and there is a company now that makes hot plates that get up to 1004 degrees (e-mail me for the name because I'll have to look it up). They start at 7 x 7" and cost $180 basically, and they go up in price from there. The real advantage to this is that we talked about sneaking in to the glass with the heat, and there are 2 ways to do this. One is with a gas fire out of your torch, which you sit and hold. Where you are going to heat it up with just gas until it’s the right time (again, I don't know how long that would be). Then you add a little bit of oxygen, and a little bit of oxygen and over a period of usually 20 to 30 minutes I will get a piece up hot enough (and sometimes longer), that I can then melt the section I am working on without shocking.

On the other hand, if you have one of these little hot plates, not always, but quite often, you can take the sculpture where you're going to be adding the component and put it on the hot plate at 1004 degrees. Let it set for about an hour, hour and a half, maybe two hours, and it will saturate about an inch and a half to two inches above the area on the surface, i.e. it gets hotter then hell for about an inch and a half. It heats the piece up at the point where it rests on the hot plate while allowing the rest of the sculpture to remain cool. Then you pick up the cool part, put the already hot part in the fire and melt it. It's already over a 1000 degrees, so there's no thermal shock when the fire hits it. And basically because of the beautiful properties of borosillicate, if you do this patiently, and you learn how, you can heat up a very small part of a very large solid sculpture, without affecting the sculpture in any way, and add to it, or clean it up, or work on it before reannealing it.

Re-annealing is the secret, and the formula is this; 1200 for Timework's kiln, 475 to 500 (whatever you can stand) for the outside kiln, and the end of the day, 1095 for 30 minutes per thickest half inch, at the end of which, you turn it off and let the temperature drop. You really need a digital readout for this, I have found that pyroneters just are not correct enough for that procedure.

But I'll tell you a secret; this is something you should do occasionally anyway if you have a top-notch digital pyrometer and controller. When your working on your sculpture, turn all your gas up and your oxygen down until you have just a little bit of oxygen, 'till you have a very gaseous fire, let the soot coat your piece, or at least a strong portion of your piece. Put it in your kiln black, basically with a jacket of soot. The reason that you're doing this is because at approx. 1095 degrees, the soot will disappear, it will vaporize. When you open your kiln, if you notice that there are areas of your sculpture with soot on it, then you did not properly anneal it. I can't emphasize this little known trick enough. If the soot is gone, you've annealed it, you've got it to annealing. If the soot is there, you need to check your digital readout and keep going until you get it to remove the soot. And by the way, this is a wonderful way to check hot and cold spots in the oven.

This process has enabled me to express myself with this material in ways I never could have without it.

Until next time, keep your fingers out of the fire and don't test the temperature of your glass with your tongue.

 

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