Beads From the Beginning.
By: Brian Kerkvliet c1995
Making the bead release, " The Secret Formula".
My previous article on studio set up and safety laid the ground work for this column about some basics of bead making that are essential to create good pieces De-Art, (with a hole through them). Like the beginning of any good structure, beads need a good foundation. In bead making the foundation is the mandrel, a metal rod which the glass is wrapped onto and the bead release (also known as kiln wash, bead separator etc.) which is used to separate the glass from the mandrel .
When I first researched materials for making bead release I went through many different formulas and tests, but most importantly I learned about the materials that go into making the release. I also tried to find out what bead makers of old used. To the best of my knowledge they used a mixture of clay and ashes. I thought to myself why clay and ashes ? I concluded that the clay was used as a binder that fired onto the mandrel and the ashes were used to make the clay more porous and brittle so that it would easily break free of the mandrel when the bead had cooled. These are the properties that I looked for when I made my first bead release.
Once you know how the basic materials work you can play with the percentages to achieve your desired effect. The basis of most kiln washes is kaolin clay and alumna hydrate, usually about a 50/50 ratio. I started with this and found that it fired on too hard. I thought about the ashes used in the old formula and tried some things that would achieve the same effect, weaken the strength of the fired clay. I tried talc, silica flour and diatomaceous earth which all worked to varying degrees. It's important thing is to understand how the materials work.
Here is a low down in simplified terms on the most common materials used in bead release .
Kaolin clay is primarily 46% silica oxide & 38% alumina Oxide. This makes it fire on hard, it's the binder.
Alumina hydrate- makes the mix more plastic and cuts down on the shrinkage. It also enables the wash to withstand higher temperatures.
Diatomaceous earth- (D.E.) is the remains of dead diatoms which is almost pure, porous silica, with some impurities of calcium oxide and iron oxide. This is used to make the release porous and not fire as hard.
Whiting- is calcium carbonate which is used as a light filler to make the release more porous.
Silica flower- this is fine silica powder which increases the strength of the fired wash.
Talc -is calcium carbonate and basically has the same properties as whiting.
Graphite powder- this increases the ease in which the bead is cleaned out inside the hole and doesn't add much to the strength or high temp properties of the wash I wouldn't use more then about 5-10%. (Very dirty stuff)
( Mikes mix 12p K, 3p DE, 3p sil., 9p graph.)
I use a mix that is approximately:
40% Kaolin clay, ( the binder)
30% Alumna hydrate, ( the high temp plasticizer and shrinkage reducer)
25% D.E., whiting, talc, or all three. (the fillers that make things break free easier)
Powered Graphite optional 5%-10% ( makes the bead slide off easier and the hole cleans out easier)
In all truthfulness I don't have an exact recipe. I start with this and test it. In order to have the "perfect mix" you may have to play around a bit. If it's too hard I add a filler and if it is too soft I put more binder in, simple as that! The simpler you keep it the better off you are going to be.
Before you start, don't forget that you are working with materials that are nasty to your lungs, so put on you respirator! Measure the ingredients by dry weight and mix them together thoroughly. Then gradually stir it into water, so as to avoid lumps. I mix this into a consistency that is quite thick, like paste. Then I take a few tablespoons of this concentrated mix and in a separate container and add enough water to dilute it down to a pancake batter consistency. I use a tall narrow container for dipping my rods.
There are two reasons that I do it this way. First, you don't have to mess with the nasty dusty components as often if you make the concentrate and then mix it down. I haven't mixed up a batch in 2 years! Secondly, by mixing the ingredients together with water first, it enables them to fully hydrate and bond with one another better which makes for a more consistent release.
If you don't want to go through the effort of making up your own mixture and saving a bundle of money, there are several bead release formulas available out there.
From Frantz Bead Co. there is Black Fudge! It is quite easy to use, no mixing or thinning, It comes wet and ready to use. This is relatively new on the scene and is a take off of his original recipe, with the addition of graphite and silica. I have tested Black Fudge and found that it has good holding strength for making larger beads and yet allows you to easily remove the bead. The holes clean out completely with ease !
From Ed Hoy's there is the pink" bubble gum" Bead Separator. This comes dry and you can mix it up with water to your favorite consistency. This mix seems to work just fine if you don't force the bead too much and break the kiln wash free of the mandrel.
From Arrow Springs there is Sludge, a mixture of Zircon and Graphite. It comes mixed wet in a concentrated form that can be thinned down with water. Or you can get it mixed to the proper consistency. I find that this release is good and breaks free when you want it to. It also cleans out of the hole nicely.
So take your pick, buy a pre formulated wash, or make your own "secret formula" that works for you and buy glass with the money that you save.
Different mandrel types and handles
Many types of materials can be used for mandrels. After having tried copper, brass, regular steel and stainless steel mandrels, I prefer the stainless steel because: 1- It is capable of withstanding high temperature without bending, 2- Its' surface remains smooth even after many beads have been made on it, 3- I t has a higher expansion rate than the glass. When the bead is being wrapped around the mandrel the stainless steel expands more than the glass. When both the bead and mandrel cool the mandrel shrinks slightly more giving a little more space to get your bead off. You can get stainless steel rod in a wide variety of sizes from your local welding supply shop. Make sure that they don't give you stainless welding rods that are flux coated, they won't do you any good at all. The rods that I'm talking about are used for TIG welding. They come in three foot lengths which you can cut down into thirds or fourths depending on your preference. Some welding rods have stock numbers stamped on the end, these must be cut off. Then grind or file the ends to eliminate the burr that's there after you cut them.
It is Interesting to note that when I first started experimenting with different mandrels I was told that the Italians used copper mandrels which were dissolved in nitric acid. I tried this and it took forever to eat out the wire. I have since heard that it was not a wire that they used but a thin sheet of copper rolled up into a round rod, the beads are then made on this without any release. The coiled sheet allows the acid to penetrate better.
Now that you have made your mandrels, you can either use them with or without handles. A lot of people I know don't bother to put handles on them, which is OK if you don't mind turning a small rod in your hand, or possibly getting carpal tunnel! Should you decide that you want handles, there are several options . The simplest is just to use a dowel of a comfortable diameter and drill a hole in the end and poke the mandrel into it. In order to keep the mandrel from turning in the dowel it may be necessary to lightly hammer the end flat into a little spear point before inserting it into the dowel, or drill the hole slightly smaller then the diameter of the wire that you are using. However if you have a kiln that requires you to put the whole works into it, you may have a problem with wood smoke in your studio. You can put the bead and mandrel inside the kiln and leave the handle outside, If your kiln is designed in such a way that enables this. Another option is to use one of those self clamping draftsman pencils, the ones that you push the button on the end and it opens the jaws to put a lead into. They make several different sizes which accept different diameters of lead, or mandrels as the case may be. These are nice in that they allow you to release your mandrel with the push of a button. If you want to make a bead with a big hole you can use a piece of stainless steel pipe dipped in the kiln wash. Even small core vessels can be made using this method. There are some other methods to make nice core vessels that I will explain in another column.
Winding the glass onto the mandrel.
There are several different methods of this basic technique and I don't want to say that one is right and the other isn't. What I will try to show is that they all have a place, there is a time to use one and a time to use another.
The first process I call coiling. This is done by heating enough of the glass rod so that you can wrap it at least once around the mandrel before you have to heat up additional glass. Start your wrap perpendicular to the mandrel and continue around until you get to where you started, as you go over that point give a little push so as to squeeze the glass out even with your starting point. Then you angle the glass diagonally so that it starts to form a spiral on the mandrel as you continue to wrap the glass around it. As you continue to spiral the glass around the mandrel remember that you want to keep the flame focused on the glass rod at the point right before it goes onto the mandrel. I find that if you gently rock the glass rod back and forth it heats a lot more quickly and evenly, thus it flows on the mandrel much more smoothly. These coils should be laid on so that they slightly overlap the previous coil. When you have finished coiling the length of the bead that you want continue to wrap one final wind on the right side of the bead so that the end of the bead is square to the rod. This additional build up of glass on either end of your bead will help keep you from getting those sharp pointy ends that are so common on beginners beads. This is a good method for laying down your initial layer of glass or a simple clear case.
The other basic method for laying glass onto the mandrel I call "gather and blob". This is essentially what It sounds like. You start out by heating the end of your glass so that it gathers up into a little ball. Just before this ball feels like you can't control it any more you blob it onto the mandrel and spiral it around until you run out of melted glass. Then trail it off and repeat the procedure. Do this until you have enough glass on the mandrel to marver it into a bead. Now this method sounds a little haphazard, and it is if you are using it for laying down the foundation glass, but it is good for casing 3-D inclusions, if done right.
Keeping the ends nice and even, not pointy!
There are several tricks that can help you keep from getting those pesky sharp ends. I have already mentioned one, add more glass to the ends and marver it in. After you get the amount of glass on the mandrel don't over heat the glass! When you over heat the glass its surface tension will cause it to migrate towards the middle of the bead, leaving the ends nice and pointy. If for some reason this should happen don't panic! Use heat and gravity to remedy the situation. By heating the bead up and holding the mandrel at approximately 30°angle the glass will flow down to that side of the piece and if you are rotating your mandrel evenly you can create a nice little pucker at either end of your bead. After you have formed that little pucker, you want to set the glass by chilling it with your marver. First on one side then the other. (Illustration sequence 1-5) After you do this process try not to overheat the bead which would again cause the same problem.
Safety, Eye Protection
The safety topic this column is eye protection. As we all know our eyes are the most valuable assets we have. Without them we wouldn't be able to play with this magical glass. We should all take ample precautions to protect our eyes from flying glass shards and the harmful electromagnetic radiation that is given off by working with glass.
As with any hot object like a kiln element, or the Sun, heated glass can emit a significant amount of electromagnetic radiation in the infrared portion of the spectrum, from 750 -12,000 nanometers (Nm). This is the portion of the spectrum that has been known to cause eye damage with prolonged exposure. Like cataracts man! For quite some time flame workers have mainly used the rose colored didymiums. Made of two 'dymiums', Neodymium and Praseodymium, both are rare earths. This is a dichroic lens that looks rose colored under incandescent light and bluish under fluorescent light. It transmits approximately 80% of the visible light, with the exception of the range of the sodium flare which is between 575 to 600 Nm. It also offers good protection against ultra violet rays. But it falls short in the filtration of the near to mid infra red spectrum. If you are working small pieces like beads the amount of infra red that is given off is not substantial, however over time it has the potential of harming your eyes. The larger and hotter pieces you work on, the more infra red (IR) you expose yourself to.
There is a new lens on the market called AUR-92. This lens was originally developed for enhancement of the primary colors; red, green, and blue. It gives you approximately 75% transmission of the visible spectrum and has excellent filtration of the sodium line. It gives a little better protection in the near to mid IR zone. (See graph for comparison.) This lens is not going to give you significantly better color rendering or IR protection, but it is slightly better then the regular didymium lenses.
When you look at the graph, the higher % transmission in the visible spectrum, the better off you are going to be for color accuracy. For the best protection you want to be as close to 0% transmission in the UV range(0-400Nm), the sodium line (575-600Nm) and especially the IR range (770-12,000Nm). So you can see in the graph that the AUR-92 does filter out more of the IR, as well as allowing more transmission of the blue portion of the spectrum.
In order to get better IR protection you may want to use an additional plastic clip-on welders shade #3 or #4 which allows 9% and 5% IR transmission, respectively . However using these lenses will drastically cut down on your ability to see what you are doing. You can solve part of the problem by using a partial lens that covers only the top third of your viewing area. You can look through the top portion of the lens when your bead is in the flame, and when you are looking for another piece of glass or a tool you can look through the bottom portion of the glasses. A little awkward, but it gives you better protection.
The bottom line here is pay attention to your body! If your eyes feel tired and sore at the end of a torch session, maybe you need better protection. I know people who have been lampworking for 15 years who have not had any problems using only didymiums. Then I have heard of people who can't work for more then an hour before there eyes get sore. So pay attention! One more thing that you want to be aware of is staring. If you stare directly into the flame for uninterrupted periods of time you are bound to have problems. You want to get into the practice of shifting your focus from near to far. While you are working, glance at other things from time to time to break the tendency of staring. If you get into this practice I guarantee that you will feel better! While we are on the subject of feeling better why don't you get up and stretch every now and then too.
I hope that this information has been useful and would welcome any comments, suggestions or questions which you would like to see addressed in future issues. In the next issue I will explain several different ways to make wild twisties and other decorative cane. I will also evaluate several bead kilns and some basic controllers. So keep you subscription current and watch your mail box!