June/July 2009 Volume 23, Number 1. $10.00
www.HotGlass.com Incorporating Privileged Information
Featuring Bashi AlĂŠ Eric Goldschmidt Christopher Hurley Denise Koyama Harry Kravet Mark Lammi Tim Lindemann Louise Little Ryo Ono and more...
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Lidded Incalmo Candy Dish
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ncalmo is an Italian term for joining two or more differently colored bubbles together into one bubble. In addition to being a good production piece for me, this candy dish is an excellent skill-builder for my hollow work. I think it’s a great piece for flameworkers to use to build their goblet skills. There are some fundamental issues that the glassmaker must tackle when making any hollow item. First and foremost, we must learn to see the heat in the glass in order to heat the material evenly. If the glass is not heated evenly, it can never be shaped evenly. I always try to impress upon my students that they must get tuned into judging the glow of the glass. As you read this lesson and attempt this piece, try to pay close attention to where I focus the most heat on the glass. It is also essential that you keep the piece centered at all times. As soon as you notice that the piece has fallen off center, the first order of business is getting it back on center. If the piece is off-center, you cannot turn it evenly in the flame, and you cannot heat it evenly or shape it evenly. A common mistake I see as my students learn to blow forms is that they blow too soon when they first come out of the flame. Relax when you come out of the flame. Give the heat a chance to even out, and then blow. I also tend to blow in progressions. When you blow the first time, all the hot glass will inflate. So, blow a little bit; take a look at what you have accomplished, and be sure that you are still on center; then blow again. I usually inflate the glass three times per heat. Each successive time you blow, the thinner spots will have stiffened and the thicker spots will continue to inflate. This will help you form even-wall thicknesses throughout your bubbles. Walls of even thickness will give your pieces greater structural integrity.
Lidded Incalmo Candy Dish Text by Eric Goldschmidt Photos by Maria Strinni Gill
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For this dish, I use 38.1 mm Asian colored tubing. I have found that a 4-inch section of my main color and a 1 1/2-inch section of my accent color makes for a good balance of color and scale for the dish itself. I then use a 3 1/2-inch section of the main color for the lid. For this particular dish, I use amber as my main color and black for my accent color. June/July 2009
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In the first photo, you will see my tool set-up. I always set up my tools in the same order. That way, I hardly even have to look away from the piece to grab the tools I need. Mounted to the torch is a bracket that runs about 1 1/2 inches above the torch and is held in place by a hose clamp. There are other forms of this type of tool on the market. Whatever you choose to use for this necking tool will work, as long as you can cut into the hot glass effectively. This simple tool is extremely effective in controlling goblet lips, amongst other shaping uses. On the table moving out from the torch, I have diamond shears, cup shears, two sets of jacks, graphite parchioffis, a block of beeswax, two sizes of claw grabbers, a large graphite paddle, tweezers, a scoring knife, and calipers. It is important to keep the blades of the jacks off the table so you can grab them quickly with the right grip, and to keep them from picking up dirt or scraps from the table. You will want to pay attention to the grip that I use to hold the jacks, and the angles at which I use them to approach the glass. The blades of the steel jacks must be coated with a layer of wax. Otherwise,
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they will get stuck to the hot glass as you try to use them. When the blades are warm, simply brush them across the block of wax to coat them. Always avoid using the steel blades in the center of the flame. Too much heat can destroy them, and they are not cheap. Common mistakes I see my students make when getting used to using the jacks are: 1. Gripping the jacks incorrectly. 2. Resting the glass on the jacks to support the piece. You need to get used to turning the glass and using the jacks independently of one another. Okay … let’s get to work on this piece. I work from pulled points. Step 1 is to pull some points (photos 2, 3, and 4). When I pull points, I try to heat the glass at a 45-degree angle to the flame. I switch back and forth from 45 degrees in one direction to 45 degrees in the other direction, turning all the time. This allows me to heat as much of the length of the tube as evenly as possible. I set up my heat as evenly as possible around the tube as well. If your heat is not even, you cannot pull a straight point.
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As I come out of the flame, I pull very slowly. As the glow continues to fade from the glass, I start to pull harder and harder. Never stop turning until the glass has frozen! It is ideal to pull the point long enough that it works as two points. Nobody pulls a perfectly centered point every time, so it is essential to learn to center your points with the rest of the tube expeditiously. I turn the tube at eye level to see exactly how far off-center the piece might be, and to see where I need to fix it—99 percent of the time, the point has to be re-centered in the area that I refer to as the neck. This is the area where I am applying the heat (photo 5). As I heat, I try to gently work the point closer to center with the tube in the flame, and I do my final adjustments outside the flame. Never allow your hands to drift apart when re-centering your points! If anything, squeeze your hands together gently as you do your centering. If you pull, you run the risk of elongating and increasing your problem. Always center your first point before you pull the second one! If the first point is not centered, the second one will be even further off.
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The next few images show how I set up the incalmo process, which will include removing one of the points from my amber section of tube and one point from the black section. Heat the neck area of the tube, and carve in a tighter constriction with the necking bracket (photo 6). Use the diamond shears to support the point you are removing, and reheat the neckline (photo 7). While you still have plenty of heat in that neck area, use the diamond shears to tighten (not close) the constriction (photo 8). It helps to lean the end of the point against the table to support it. As the glass continues to freeze up, give a few uneven crimps with the diamond shears to set some stress in the neck. Then, simply swing through the point with the shears, and the point should break off cleanly. This should leave you with a round, centered, even hole in the tube (photo 9). If the tube does not have a clean edge to it, you can reheat the awkward material and trim it off with cup shears. If you set a good neck line, you should wind up with an even, round hole. Now it is time to open the hole to match the diameter of the rest of the tube. By opening the amber and the black sections to match the original diameter of the rest of the tube, you guarantee that the sections of tubing will fit together neatly with one another as you attach them. In order to get tubing to open evenly in any application, it is always necessary to follow these next thoughts. The opening must be kept round, on center, and flat on the plane that is perpendicular to the rest of the tube. I use the flat part of the strap on the jacks to square off that perpendicular plane of the tube (photo 10). As I open the tube with the jack blades, notice
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the angle at which I hold the blades, and where the heat is focused (photo 11). Only heat the glass that you need to affect! Oftentimes, you will flare the lip of the tube wider than the rest. If this happens, use the paddle to squeeze the diameter to the correct size (photo 12). Once you have prepared both sections, you are ready to attach them with a butt seal. Heat the lips of both sections you wish to join. When you are ready to attach them, first connect the part of the tube that is further away, and slowly close the sections together from back to front, working toward yourself. This will allow you to see the tubes throughout the connection as they come together, and it will allow you to keep the flame on the lips as they come together (photo 13).
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Once the tubes are connected, stay in the flame to smooth out the seal. As soon as the seal has been smoothed out in the flame, come out of the flame and blow in gently (photo 14). This blowing will help even out the wall thickness at your connection point. Now you are ready to blow out the rest of the bubble. Focus the flame on the left-most quarter of the tube, and inflate that section so it is slightly wider than the rest of the tube (photo 15). Reheat the area that you have just inflated. As the glass gets very soft, slowly squeeze your hands together until you fold the tube back on itself (photos 16 and 17). As you come out of the flame, you can straighten the fold with gentle pressure against the sides of the necking bracket (photo 18). This folded area will serve as the foot of the vessel. Now you can heat the rest of the amber section and blow it out into a sphere (photo 19). Heat the black section and blow it out into a sphere (photo 20). Heat back and forth from the amber sphere to the black sphere and join the two spheres into one large one (photo 21). If you continue to turn the tube faster, centrifugal force will help the spheres come together and grow larger. Heat and inflate the bubble until you arrive at a shape that resembles the bubble set-up shape (photo 22). Setting up the proper bubble shape before removing your points will make the rest of your June/July 2009
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shaping process a lot easier. This is always the case with any opened hollow form. Now you are ready to prepare the bottom of the vessel, to make it easier to remove the point from there once the lip of the dish has been formed. Heat the point, just behind the fold (photo 23). As you come out of the flame, use the necking bracket to tighten the constriction and flatten the bottom of the vessel (photo 24). Be aware that the fold can be very temperamental. If it gets too cold during the process, it may want to crack, so, as you continue to work on the top of the dish, be sure to flash the fold with the flame in between steps. To open the top of the dish, the steps are almost the same as when we opened the tube for our incalmo seal. Neck in the point at the end of the black section (photo 25). Reheat the neck area to further constrict it with the diamond shears (photo 26). Set stress with uneven crimps of the diamond shears as the glass freezes up, and swing the shears through the point to knock it off cleanly. Be sure to keep the open end of the bubble squared off to the rest of the form (photo 27).
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Heat the opening, and use the jack blades to help widen the lip and walls of the vessel. Notice how I heat the lower parts of the tube in the flame while using the jack blades on the upper parts of the tube, just above the flame (photo 28). This technique allows you to keep the heat in the glass without cooking your jack blades. Now I use my graphite parchioffis to open the vessel to the point where the sides are straight (photo 29). Finally, I heat just the lip and use the parchioffis to flare the lip (photo 30).
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The black tubing is very stiff. With softer colors or clear glass, you can simply use heat and centrifugal force to flare the lip. Reheat the lip and use your paddle to be sure that it is level (photo 31). Notice how I hold the piece straight vertically and at eye level to be certain that the lip is truly level. Be sure to turn the piece as you do this, to be certain that the lip is level all the way around the piece. I can now grip the lip of the dish with claw holders to melt off the point from the bottom (photo 32). Once the point has been removed, heat the entire bottom of the vessel. As you come out of the flame, move to the table to flatten the bottom of the dish (photo 33). Notice how I get right down to the table to view how level the dish sits. Be sure that you are turning the piece against the table to ensure that it sits straight around its entire circumference. If it does not sit straight, you can always reheat the bottom and try again—and again—until it is straight. Flame-anneal the vessel, and place it on an insulating surface. Now you are ready to make the lid. Set your calipers such that they are about ¼-inch narrower than the lip of the vessel (photo 34). Heat the next piece of tubing and blow it out into a sphere that is slightly smaller than the measurement of the calipers (photo 35). Notice how I position my calipers off the edge of the table. You can always blow the bubble larger if necessary, but it is very difficult to make the bubble smaller. Reheat the sphere and squeeze it into a more squat bubble (photo 36). It is ideal to have this squat bubble fit precisely to the measurement of the calipers. Reheat the center of the bubble and squeeze it together gently to create an area that is almost folded (photo 37). Notice where I hold the glass in relation to the flame to accomplish this shaping. Try not to fold the glass back on itself here as it will make the rest of the shaping very difficult and sensitive to cracking. This almost folded area should now be slightly larger than the caliper measurement (photo 38).
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The half of this form toward the closed point will be the top of the lid. You can now shape that area to your liking (photo 39). Remove the closed point and add on a solid punty rod in its place (photo 40). June/July 2009
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to heat the same area of the closed bubble, I use the point to strip away excess material from the bubble. As I continue to heat and strip material away from the bubble, the hot air inside the bubble will force the bubble to pop open at its hottest and thinnest point (photo 41). It is absolutely crucial to keep the bubble turning on center throughout the course of this step for this to work neatly. Be sure that the lip of this opening is squared off to the rest of the bubble (photo 42).
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I have found that the lid will sometimes crack if I leave it on the point. You are now ready to remove the other point and open the bottom of the lid. This next move is the toughest to explain, so bear with me. I heat the bubble with a sharp, intense flame just beyond the point. As that area gets extremely soft, I move the point to an angle where it is perpendicular but still attached to the bubble. The bubble is now closed. As I continue
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Now that the bubble is open, you can reheat the lip and walls of the lid and draw it wider with your jack blades (photo 43). It will be necessary to check the lid size against the candy dish (photo 44). If it is not wide enough to fit well, then reheat and continue to draw it wider with jacks or parchioffis. If it is too wide, you can reheat and use your paddle to squeeze it smaller (photo 45). You may find yourself going back and forth with the jacks and paddle several times to get it just right. Do not rush this part. You have made it this far, and few things are more frustrating than putting the pieces down and realizing
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later that you really do not like the fit of the lid after all. You can now grip the inside of the lid with claw holders to remove the punty and add a finial to the top of the lid. There we have it: a lidded, incalmo candy dish (photo 46). Good luck with this piece. I am sure that you will find it challenging at first, but, once you get a grip on it, your skills will grow immensely. Feel free to send me any further questions. I can be reached at Goldschmidtes@ cmog.org. Eric Goldschmidt is the flameworker team leader at the Corning Museum of Glass, Corning, NY. He also teaches at public-access studios at least once a year. He is scheduled to teach at the Penland School of Crafts from August 9–21, and to offer a weekend goblet class at The Studio of The Corning Museum of Glass on October 3 and 4.
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