By Brian Kerkvliet, Copyright 1996
Glass marbles have been around for a long time. Your great grandfather probably played with them when he was a kid. Most of the older marbles have ended up in someone's collection. Most likely these collectors are children at heart, or perhaps they played with marbles as a kid, but the fascination with these round marvels of glass still captivate their imaginations and dreams. How many times have you been asked, or have wondered yourself, how do they get the marbles round? Well they didn't take a glob of molten glass into space and allow the surface tension of the glass and the antigravity of space to work their wonders, although that may be the way of the future! Space marbles!
There are many different ways that marbles were mass produced. Most glass workers don't have access to the equipment needed to mass produce marbles, so I am not going to talk about these processes. Besides, mass produced marbles are simple and boring! I'm going to talk about contemporary art marbles. The cool wild ones!
Recently there seems to be an increased interest in new marbles, by collectors of old marbles, kaleidoscope makers and collectors, glass bead makers, and a number of other fledgling glass collectors. There is something really appealing about seeing a bowl full of marbles. There is so much diversity and spectrum of color who wouldn't be fascinated with them?
Essentially there are two basic approaches to making glass marbles by hand. The first is to create the body of the marble for each individual marble. This is truly a "one off" marble. Generally these take a lot more time to make and therefore they tend to be more expensive. However, by making each piece one at a time you can get some wonderful results. You can create a body of glass in much the same way you would make a bead, but instead of winding the glass onto a wire, wind it onto another glass rod until you have enough gathered to make a marble the size that you want. This gather can be decorated in the same way that beads are decorated. You can feather them, apply dots, stripes, make inclusions, and any other pattern your heart fancies. Once the body of glass is decorated , the process of making the actual marble is much the same for both methods.
The second way to make a marble is by making a marble stock or large cane, from which several marbles can be made. This is sometimes known as "working off the hump". For obvious reasons, the idea of working off the hump is very appealing. The main reason is that a glass worker can spend time making a very intricate cane and then proceed to make numerous marbles from it. This can be done a lot more easily then making them "one off". I have detailed a few of the many techniques to make latticino or twisted cane in my article "Twist and Shout of Lampworking", (Jan. / Feb.95 issue of Glass Art.) These same techniques may be used to create a marble stock from which you may then make numerous marbles.
One way that you can make a simple marble stock is by laying up strips of sheet glass making an ingot of clear glass surrounding strips of color.(Ill.1) When laying out these strips of glass use only double rolled clear so that the chances of catching air bubbles is lessened. Make the ingot about 1.5" wide by 2" tall by 3" deep. I usually make five or six of these lay ups and fuse them at the same time. Place the stacks of glass into the kiln on shelf paper, or on a well kiln washed shelf. Then make a dam on either side of the stack with some kiln washed fire brick. This keeps the stacks from totally going flat when they are tack-fused together. You want the stack to be slightly taller then it is wide because when it's fused, it will shrink down a bit. It is best to fuse these ingots at 1400°F for about ten minutes or so, then let the ingots anneal and cool down to room temperature. This allows you to clean the ingots of any remaining kiln wash. Once they are clean you can place them into the kiln and bring them back up to temperature with the process that I describe below. Once these ingots are picked up and placed in the torch you can shape them into cylinders with the marver paddle, twisted and pulled out. If these are too long when they are pulled out you cane cut it in half and place a portion of it back into the kiln. You can then proceed to form marble out of the remaining stock.
The Magic Marble Blocks
There are two main things that you have to remember when making a marble. The first is that glass is a liquid, and like any liquid its surface tension dictates that it wants to become round. The second thing to remember is that the marble will only be as round as you are able to rotate evenly. In theory you can make a nice marble using only these two principals. I have done this successfully but it is somewhat slower than when you use a marble block. It is preferable to use a marble block to help you shape the sphere but it is still critical that you rotate the piece evenly, while heating it enough so that the surface tension helps to make it round.
There are two different kinds of marble blocks that people use. Basically they are the same type of tool, only made out of different materials. The cheaper way to go is by using blocks made out of cherry wood. These must be used wet or they burn up prematurely. Even when used wet they have a relatively short life. I would say that they pass their usefulness and have to be replaced after about 25-35 marbles. As you use them they burn out slightly and enlarge in size so if you are trying to make marbles that are the same size to one another it can be very frustrating to use wood blocks. The people I know who use wood blocks primarily make furnace worked marbles, large ones at that. They do burn out but they are relatively easy to make and therefore cheap to replace. Wood blocks tend to not leave chill marks on the glass as easily as graphite blocks do. If you decide to use wooden blocks there are several things that you need to do to make them work properly. First of all they must be stored in water, as well as used wet. This means that they must have their own bucket of water which is their home. Even when you are not using them they must remain in the water because if they dry out, they are prone to crack which would render the molds useless. This water needs to be changed periodically or it will begin to stink like rotten wood. When you use these blocks it is important to dip them into the water between each use on the glass. Sometimes even more often than that, to keep them from burning out too fast.
The other marble blocks are made out of graphite and will last a long time, providing you take care of them. They are a little more expensive, and slightly harder to make, but I feel that they are worth it if you are planning to make many marbles. By using graphite you assure that the block won't change in size which gives you the best possible quality control. Graphite tools tend to leave chill marks until they heat up a bit, at which time they work great! They are a bit more delicate then the wood molds, so you don't want to drop them or bang them around, but if they are treated carefully they should last a lifetime.
Making the perfect sphere
I will describe how to make a marble from a chunk of marble stock. Aside from the preheating in the kiln, all of the steps described are the same if you want to make marbles "one off".
Place a section of marble stock about 4-5 inches long into a kiln and slowly bring the stock up to 100 degrees above it's annealing temperature ( roughly 1000°-1050°F). Soak it at that temperature for at least 15- 20 minutes. This assures that the cane has little thermoshock potential when you put it into the flame. If you are not sure how to ramp the glass up to annealing temperature checkout my article on annealing, "Magic Kiln Tactics" While the cane is soaking you can take a 12mm Pyrex rod and gather up a ball of glass on the end of the rod.(Ill.-2) It is recommended to use a Pyrex rod for a handle in this process because it is strong and is less apt to crack during the marble shaping process. When you have a gather of about 3/4 of an inch or so, use a graphite paddle to squash the end of the gather so that you have a disk like paddy on the end of the rod. (Ill.3) You will use this disk to pick up the marble stock out of the kiln. When the marble stock has soaked long enough, heat the very end of the disk and reach into the kiln and stick it onto the end of the marble stock.(Ill.4)
Quickly place it into a large bushy flame and evenly bask the stock in the flame. As it heats up you can dial in a hotter flame and start heating the very end. During the whole process of shaping the marble, it is important to periodically heat the whole assembly, Pyrex punty and marble stock, so that it won't crack while you are working on it. It may seam obvious to some but I feel compelled to say it again, "you have got to keep it turning!! This is the only way we mortals can counteract the effects of gravity without leaving the planet. Once you have this understood everything else is easy!
Heat the end of the cane and use a pair of scissors to jack the end down so that it brings the design together into a point. Knock this portion of the rod off and clean up the tip (ill. 5) Now focus the heat on an inch or more of the end of the rod until the glass starts to move, then gently place this portion into the marble block. (While turning, right?) The first time that you place the glass into your block you are not really trying to shape the marble, you are trying to measure the amount of glass that will be needed to fill the block. So just use it as a gauge and let the block make a little line where it needs to be jacked down. Heat this line and use the scissors to jack the area of the line down so that there is only about 1/4 of an inch attaching the future marble to the remaining marble stock. (Ill. 6)
Using scissors like jacks require a few considerations. First of all you need the right pair of scissors. I recommend finding a pair of surgical scissors with long slender blades, preferably a pair with large handles that you can get your fingers into and out of easily. The thin blades don't pull as much heat out of the glass as thicker metal would, enabling you to work the glass a little longer. The other important thing is to use a bit of beeswax on the blades of the scissors. This helps keep the blades from sticking to the glass as they get hot. Once these scissors are used as jacks it is hard to get them to cut any glass because they become slippery with wax on them. I have a pair of scissors that are dedicated for jacking things down and several other pairs that are for doing a variety of cuts in the glass.
Next, heat the portion of glass that has been jacked down on the end of the marble stock. (Ill.7) When this is quite hot place it into the marble block and rotate it lightly in the block. (Ill.8) You want to focus the pressure of the block first at the jack line and then rock the block so that it progressively moves towards the end of the marble. After the first shaping you should have the marble basically shaped. It may be necessary to repeat this process a few time to fine tune the shape on one part or another. After you get it pretty close to perfect, you want to heat up the jack line again and use the scissors to jack it down a little more. This will enable you to shape that side of the marble easier after you punty it up. Now look at the marble carefully to see if there are any chill marks left on the marble from the block. Chill marks look like little ripples on the surface of the glass. These chill marks can be easily erased by lightly heating up the surface of the glass until the ripples smooth out.
Now it is time to punty up the marble using a 4-6mm clear rod. Preferably the clear is of the same coefficient of glass that the marble is made from. This is because you don't want to leave any of the punty glass on the marble when it is finished unless it is of the same compatible material. Take this clear punty and marver it into a nice point, now heat the very tip of it and lightly attach it to the opposite end of the marble, in the center. (Ill.9) The ideal punty should go on slightly hot with the piece that you are punting up being colder then the tip of the punty. This heat difference sets up a slight stress line that will facilitate a nice separation when it is time to remove the punty and fire polish the mark left behind. When you are sure that the punty is securely attached, focus the flame on the jack line and heat it so that you can separate it from the remainder of the marble stock. Place the remainder of the marble stock, still attached to the Pyrex handle into the kiln to keep it warm. (leave the handle Out of the kiln so that you can grab it again, silly!) Now focus the flame on the portion of the marble that you have just removed from the rest of the marble stock, then gently place it into the marble block and rotate it until smooth. Check for chill marks and fire polish out if necessary. Now it is important to allow the marble to cool off in the interior so that it won't squash when you grab it with the marble tweezers. Do this by keeping the marble hot in the outer portion of the flame for a while. Then let it cool down enough on the outside so that you won't leave marks with the tweezers when you grab it. Grab it firmly with the marble tweezers and with a swift movement snap it off of the punty. If it doesn't want to come off of the punty very easily it may be necessary to chill it with a cold metal tool, ie. another pair of tweezers or tile nippers. Tile nippers are a good last resort, but if you have done the punty correctly it will come off nice and smooth, with only a small divit to be fire polished out with the flame. Punties are one of those things that need to be practiced only a few hundred times before you get them right. After that they are a piece of cake! Take this newly completed marble and roll it into the annealer, grab the Pyrex handle that has the remainder of marble stock on it and begin the process all over again until there is no more stock to use. Each marble can be the same size or not. It can be made out of just the marble stock or you can embellish the marble stock more as you form the marble. The options are unlimited.
I feel that it is safe to say that not everyone has lost their marbles yet! And if they have, we still have the knowledge to make more! Let there be marbles of all colors, sizes and styles as long as they're round. Hopefully they will help everyone who comes in contact with them find a little bit of their inner child and bring a smile to their face. Not to mention that the kids will love them too.
List of marble specific tools
These are a pair of tweezers that have a washer or wide tip which has a hole or depression. For smaller marble you can use a pair of pearl sorting tweezers. You can purchased these from most jewelry supply houses.
These are made of wood or graphite and generally have a hemispherical depression carved into the material with an attached handle. Most lampworking supply companies offer several types. Wale Apparatus, Frantz bead, Ed Hoy, Arrow Spring.
These are described in more detail above in the article. They can be found through a surgical supply houses or, if you're lucky, a flea market or swap meet. ( That is where I found mine.)
Marbles on the Web!
The following is an excerpt from an article on collecting marbles as, well as some listings, that I found on the World Wide Web. These are used with permission from the Marble Collectors Society of America. For more information on the Marble Collectors Society of America, contact Robert Block at: firstname.lastname@example.org
"A handmade marble is a thing of beauty and a technical feat of glasswork and art. In reality each handmade marble is individually crafted by a person. This cannot be said for machine made marbles. Each handmade marble carries with it the individual stamp of the craftsman who created it. This is in the twist of the marble and in the design and the colors. The appeal of handmade marbles lies in their individuality. No two canes were the same, and no two marbles off the same rod are exactly the same. You cannot say that about most machine made marbles.
Single-gather marbles could require less steps, but only one marble was produced at a time, rather than a whole set of marbles off of one cane. Suffice to say that the production of handmade marbles was a fairly laborious task. As a result, far less handmade marbles exist than machine made marbles, therefore increasing their value. "