So you want to make a bead...
Beadmaking can be entered into with almost no expenditure -- just to see if it's something you'd like to do -- up to spending a cool grand, or even more, if it's something you want to get serious about.
What's involved in making a bead? It's really nothing more than heating glass to working temperature, (around 1700-1800 F.) shaping it, and cooling it at a controlled rate.
For making a simple seed bead, you'll need the following items:
The first thing you're going to need is a workspace. The appropriate place has a fire-proof base or floor, so in the event you drop molten glass, you don't start a fire. My "beadmaking places" have ranged from sitting on outside steps over a concrete walk, to the top of my kiln, to a workbench with a 12 x18 inch piece of roofing slate, or a 16 inch diameter sheet of stainless steel on it. It doesn't really matter what or where your work surface is, just so it's fireproof, comfortable to work at, and out of the way of children and pets.
If you just want to try this out to see if it's something you want to get into, you can do some trial beads using an ordinary propane torch. This won't get quite hot enough for you to do much quickly, but when you're first starting out, sometimes it's better that things are going slowly. Heating a bead too quickly when you're starting out often results in a blob of molten glass on your work surface.
Propane, when burned in air, will discolor whites and pastels, and will cause reduction (chemical reaction opposite of oxidation) in some other colors, producing, for the most part, undesirable color shifts.
Using MAPP gas (a proprietary mix of LP and methyl acetylene-propadiene, available in standard 1 lb canisters at hardware and department stores, or at welding supplies in larger bottles) will result in slightly less discoloration, and will yield a slightly hotter flame, but neither of these gases burned in a standard department store torch will be satisfactory for much more than practice.
There is a torch called the Turbo-torch which is a lean-burn propane torch. I've never used it personally, but what I've read about it suggests that the muddying of colors with this torch is only marginally less than with a department store propane torch.
About the lowest end torch you can buy for making "good" beads,
is the Hothead. This torch has a slightly larger orifice (for
more heat) and a proportionately wider burner tip (which allows more air
to mix with the gas for a cleaner burning flame). It is designed for
burning MAPP and propylene gasses.
You can still get minor discoloration of white and pastels when using this
torch, but the problem is greatly reduced, and with care and practice, you
actually can make a white bead with it. I even made a
1-1/2 inch bowling pin using this torch, and the white of the pin is as white
as the rod.
Many serious bead hobbiests never use anything other than the Hothead. (around $40)
Unfortunately, there isn't really any intermediate step. Going up from the Hothead, the next step is an oxy-propane set up. This will require either buying or renting an oxygen bottle. You'll also need propane and oxygen regulators, hose, and the torch itself. (and of course, the propane bottle)
The torch will fall into the category of either a pre-mix torch or
a surface-mix. The pre-mix torch mixes the gas and oxygen inside the
torch body or the tip, while the surface-mix burner has the oxygen and
gas mixing outside the torch. Many beadmakers say they don't get the same
crisp colors with a pre-mix as with a surface-mix torch.
(full oxygen and propane bottles with regulators and hoses - around $275 - $350, depending on oxygen bottle size and arrangements)
I use a UniWeld acetylene cutting torch, fed with oxy-propane. It is a pre-mix, but the gasses are mixed for only about 2 inches before exiting the orifice, and although it wasn't designed for bead making, I find it works quite well as long as I adjust the flame to oxidizing, and work the glass in the back portion of the flame. (to minimize bubble formation)
The industry standard for working borosilicate glass (like Pyrex) is the National 3A Blowpipe. This, too, is a pre-mix torch, and is not widely used in beadmaking, though some beadmakers have managed to turn out beautiful beads with it, particularly when burning an oxygen-MAPP mix. The National 3A Blowpipe torch body goes for around $60. Burner tips can run anywhere from $25 to $60.
The surface-mix torch burns cleaner because the gas and oxygen never mix until they're actually at the flame front. In the pre-mix torch, the oxygen and propane begin reacting before they get to the flame front, so instead of just having oxygen and propane mixing and burning, you have oxygen, propane, and partially oxidized hydrocarbons. Another advantage of the surface-mix torch is that it burns more quietly for a given amount of heat.
The Minor Bench Burner is the staple of the beadmaking industry and is, naturally, a surface-mix torch. It costs around $170. Larger surface mix torches for lampworking can run anywhere from $300 for the Nortel mid range burner up to $900 for the Bethlehem Starfire Burner.
For practice beads, you can take that window glass you had for cutting practice, and cut some thin strips about 1/8" to 3/16" wide.
If you have some stained glass handy, your practice beads will be that much more interesting.
Stained glass can make some very nice beads. The one thing you have to bear in mind is that different manufacturers of art glass use different formulations, and the COE (coefficient of expansion) varies widely from maker to maker.
Bullseye, for instance, tests their glass to insure all colors are compatible with each other. They have long made their glass with a COE of 90.
Spectrum, on the other hand, manufactures all their glass with a COE of 94-96, but they don't test to make sure all of their glasses are compatible with each other... they leave that up to us.
Uroboros makes a line of COE 90 that's tested compatible with Bullseye clear, and they also make a COE 96 that's tested compatible with Spectrum clear.
Now, if you have a box full of stained glass scraps, but have no idea who the manufacturers are, it might be a good idea to use this glass just for single color beads. You can try multicolor beads, but if you come up with one you really love, you'll be really disappointed when it eventually shatters...
What happens when you use glasses with different COE's is that as the bead is cooling, the different colors are contracting at different rates, creating internal stresses. If the difference is pronounced (like a difference of 5 or 6) the bead probably won't be in one piece by the time it hits room temperature. A moderate difference (like 3 or 4) will likely result in a bead that will last a few days, or maybe even a week. A slight difference (1 to 2) and your bead may well last months or even years (especially if it's been carefully annealed) Glasses are normally considered compatible if their COE's are within 1 of each other.
Then there's the "right" way to do it, which is to go down to your stained glass store and buy (or order) some Moretti rod. This comes in 6mm dia. x 1 meter rods. Moretti happens to be a brand name, but it is usually the one you hear in conjunction with this type of glass. I believe Moretti has recently been bought out by, or merged with, Effetre, so, these two names seem to be synonymous. You will often see other glasses referred to as being compatible with Moretti. What that means, specifically, is that the glass has a COE (Coefficient of Expansion) of 104. This type of rod comes in a vast array of types and colors. You can get transparents, pastels, alabasters, opalines, filigranas (small core of color encased in clear), and even dichroic coated rod.
Borosilicate glass is only rarely used in beadmaking. There are some
brilliant colors in borosilicates (which is what Pyrex is) but the higher
cost, (in the neighborhood of $40 to $60/lb) and higher working temperatures,
for the most part, take this out of the beadmaker's daily repertoire.
|Stained glass||88 - 98|
The COE number is actually a sort of shorthand. The 32 for Pyrex means 32 x 10-7 (or .0000032). This means that for every degree Celsius change of temperature, a one inch dimension of that glass will change .0000032 of an inch. (or put another way, Pyrex will contract or expand .00032% of its length for each degree C. of change)
A mandrel is simply a wire or rod upon which you form the bead. When you remove the bead from the mandrel, a hole will be left. Mandrels can be anything from a coat hanger (yes, I've done that) to stainless steel welding rod, to store-bought bead mandrels.
The important thing about mandrels is that at the heat of gooey glass, oxidation is accelerated. A coat hanger mandrel will work fine... for a few times. Each time you use it, new pits and corrosion will appear. The same thing happens to the stainless steel models, but at a much slower rate.
Pre-manufactured mandrels normally come in lengths of around 9 inches with diameters of 1/16, 3/32, and 1/8 inch. This will be the nominal size of your hole but the hole will actually be just a bit larger, due to the thickness of the bead release.
Bead release is the coating applied to the mandrel in order to prevent the hot glass from fusing to it. When molten glass comes in contact with hot metal... well, let's just say you'll end up with a permanent rod though your bead, unless you're willing to use your hammer. The release prevents the molten glass from coming in direct contact with the mandrel. When you remove the bead from the mandrel, there will be a white residue inside the hole that will have to be cleaned out. There are a variety of tools to do this, ranging anywhere from wires with ridged teeth, to bits you put in a high speed Dremel type tool. Naturally, a clean hole is of more import in beads of transparent glass.
Bead release is normally based on a high-fire clay, with binders, and other additives. Mix it with water according to the directions, and dip your mandrels into it. Let your mandrels dry, and depending on the particular bead release, and your personal preference, you may want to dip them a second time. Let them air dry, or you can accelerate the process with a hair dryer, or other gentle heat source.
INSULATION / KILN
After the bead is formed, it must be cooled slowly to avoid cracking due to thermal shock. The most commonly used methods for avoiding thermal shock are ceramic blankets, pre-heated vermiculite, and bead annealing kilns.
When asbestos was found to contribute to certain nasty lung conditions, alternatives were developed, and these ceramic fiber blankets are every bit as effective as asbestos was, but much more user friendly. As soon as the bead stops glowing, it can be set on a one inch blanket, and a layer then folded over the top of the bead. Subsequent beads are then laid close to, but not touching, previous ones.
Vermiculite is a well-known insulator as well. It can be used at room temperature, but is more effective if pre-heated. This can be done in various ways (coffee can on hot plate, wood stove, or kerosene heater) so that when the hot bead is plunged into it, the immediate cooling rate is less than it would be in cold vermiculite.
The best way to treat a bead right after you've made it, is to place it into a kiln that's sitting at 800 degrees. When you've finished with that batch of beads, you can then take the kiln up to the annealing point of the glass you're using, (968F for Moretti) let it soak at that temperature for several minutes, and then let it cool slowly over a period of a few hours. (see the section on Kiln-formed glass for more on annealing)
The only way to insure your beads will be around for the next generation to enjoy is if they are properly annealed. Even if you cool them very slowly in the ceramic blanket, or heated vermiculite, that is really only a stop-gap. There will still be internal stresses created when the outside of the bead cools more quickly than the inside.
Many people who don't have a kiln use one of the slow cool methods, and then when they get a sufficient quantity, take them to someone who has a kiln for annealing.
At the very least, safety glasses with side shields should be worn. When you first insert the glass rod into the flame, there may be some spitting of the end of the rod. Small pieces of glass pop off the end and fly in any direction they choose. If that direction happens to be where your eyes are, you want something in front of them.
As to the color of the glasses, there seems to be much controversy on that point. Many glass furnace workers in Corning, NY have worked around yellow-hot glass for years, without any special precautions against UV or IR radiation, and have sustained no adverse effects. Others have worked around lampworking torches for as little as two or three years, and have developed cataracts. Coincidence? Maybe... Controlled studies seem to indicate that excessive amounts of ultraviolet light can contribute to the formation of cataracts, and excessive amounts of infrared can contribute to thickening of the lenses.
The $64,000 question is, "Just how much is excessive?" So far,
there is no definitive answer, but preliminary findings suggest that the
amount of infrared from a beadmakers torch is not excessive.
As to UV radiation, there is, practically speaking, little emitted from glass at these temperatures.
Shade 3 welder's goggles will absorb what little UV is here, as well as cutting back on the intensity of the light which reaches your eyes. They will also greatly shift the color spectrum.
Didymium lenses will reduce the UV, and will block the yellow sodium flare from the flame, making it much easier to see what you're doing, and if glass, will also cut back much of the IR.
Gold coated lenses are very expensive, but will reflect virtually all
of the UV, IR, and sodium flare.
Probably the prime considerations here are, How much time are you going to spend in front of the torch? And are you going to be doing a lot of Pyrex work?
My personal opinion is that if you're going to make a living in front of the torch, safe is always better than sorry. Go for the gold!
If you plan on being in front of the torch less than full time, the didymium will be more than adequate, and if you're just going to be an occasional weekend beadmaker, either plain safety GLASSES, i.e. with GLASS lenses or the welder's shade 3.
Glass, all by itself reflects and blocks a lot of IR and UV. Some people set up a piece of glass, about a foot square, between their eyes and the torch, and this should be more than adequate for radiation protection for the hobbiest. Spitting glass can bounce, though, and no matter what kind of protection you have for radiation considerations, it is also wise to have side shields on your glasses, or even wrap-around goggles. You never know which direction a shard of spitting rod will head, or what it might ricochet off.
The last thing you need is a 300 degree piece of glass flying into your
eye!!! The threshold of damage from Infrared and Ultraviolet radiation is
largely speculative and theoretical.
Damage from a flying piece of hot glass landing in your eye is immediate and absolute!
LET'S GET TO IT!
With your right hand, pick up a glass rod/strip, and hold it between
thumb and fingers (almost like you're throwing a dart). Play about an inch
or two of the glass into and out of the flame and simultaneously rotate it.
This is so the glass will heat as evenly as possible to avoid pieces popping
off and flying every which way. If a little shard does pop off, don't worry
about it. It's not hot enough to start a fire. (and anyway, you've already
cleared the area of any combustibles, right?)
Shortly, you'll see the very end of the rod begin to glow. At that point, the glass is hot enough that you don't have to worry about it popping or spitting any more.
The bead release also must be hot enough for the glass to stick to it. While you continue to heat the glass with your right hand in the hotter part of the flame, you also need to be heating the coating of bead release on the mandrel with your left hand, out in the back part of the flame. The same action is required to evenly heat the bead release; an in and out motion combined with a rotational one. It sometimes takes a little practice to get the hang of these two simultaneous, yet independent actions, but it is easier than trying to rub your stomach while patting your head.
If you try to wind the glass onto the bead release before it's hot enough, the glass just won't stick to it. If you get the mandrel too hot, the bead release will flake off and stick to the glass.
Touch the soft glass to the top of the mandrel. As it sticks, you want to move the mandrel back just out of the flame, and keep the glass right in the flame. You're heating the glass and "melting" it so you have more goo to feed the mandrel. Turn the mandrel away from you, feeding glass onto the top of the bead which is forming.
During your first few tries, don't worry about anything else but getting the feel for when the glass and mandrel are at the correct temperature. Plan on making several pieces of junk just to get this feel.
Now, as you rotate the bead slowly in the flame, the surface tension will
naturally want to form it into a spherical shape. If you rotate too slowly,
the bead will start to sag, and if you spin it too quickly, the out of
balance is accentuated by centrifugal force. Just give it nice slow
turns, and the glass will tell you if you're turning it the right speed.
Once you get the bead to the desired shape, continue to rotate the mandrel, while slowly back it out of the flame. As you back out of the flame, the glass becomes more viscous, and about the time it's dull red, you can stop spinning it. When there's no more visible emission from the bead, put it in the kiln/blanket/vermiculite. (the colors are relative, since the level of ambient light effects our perception of the color of the bead - what looks red in bright light will appear orange in darker conditions)
After the bead is at room temperature, it's time to remove it from the mandrel. Depending on the type and thickness of the bead release, this can be as simple as holding the mandrel with pliers, grasping the bead with fingers, and just giving it a little twist to break the hold of the bead release, and pulling it off. If it's that easy, count yourself among the fortunate! More likely, the bead will be stubborn. When that happens, water sometimes helps soften the bead release, and if that still isn't enough, I use a rubber jar opener to get a good non-stick grip on the bead.
One other finishing touch you won't want to neglect is to stone the sharp edges of the hole. This can be done with a standard carborundum stone, or again, there are specialized grinding wheels for high-speed rotating tools made from silicon carbide or diamond, which will not only break the sharp edges, but put a nice chamfer on the hole.
Once you've mastered the basic bead, you can start getting creative. A marver is a tool for shaping the bead while it's still soft. Usually, it's a flat piece of graphite mounted on a wooden handle. Sometimes marvers are made of aluminum, or stainless steel. They may have grooves, angles, or patterns for impressing on your soft glass.
You can make tube beads, cones, bi-cone, square... wherever your imagination leads. You can make a spherical bead, and then put little nubs of contrasting color all over it. Make a disk and then "paint" on it with rods which have carefully had only their very ends heated. Colors can be put on the mandrel side by side, or they can be put on top of each other, made to run together with a sharp stainless steel scribe, or encased in clear. Your mandrel is a canvas, and your glass selection is your palette.
Other effects can be achieved by encasing foils and leaf of precious metals in clear or transparent colors. Enamels or pixie dust (a glittery mica powder) can be applied, or even irridizing spray.
Dichroic is popular right now. You can get dichroic rod compatible with
Moretti. Bullseye, among others, has dichroic strips compatible with the
rest of their line of glass.
After you've mastered the basic bead, experimentation and persistent practice can produce fantastic creations once possible only in your imagination.
Frantz Bead Company
E. 1222 Sunset Hill Rd.
Shelton, WA 98584
Sundance Art Glass Distributors
231 So. Whisman Rd
Mountain View, CA 94041