The Art of Glassblowing
When you think about glassblowing can you imagine who would have been brave enough to attempt it the first time. When you are doing this technique you are inflating molten glass into a bubble or some other shape by blowing into a blowpipe or blow tube of some type. After certain types of glass is heated to 2400 F(-1315C) it is allowed to cool to between 1600 and 1900F (-870 to -1040C) before they start working with it. Even at the cooler temperatures that is extremely hot so who would have even attempted to handle molten glass in the first place let alone think about blowing into it to form different shapes. The individuals that do this are called a glassmiths, glassblowers or gaffers and the technique of glassblowing started in the middle of last century BC. Historians say that a glass workshop was discovered that contained fragments of glass tubes, rods and tiny blown bottles that dated back to 37-4 BC. It's amazing how they can determine the age of certain artifacts that are discovered.
Since its inception we have ended up with two major types of blowing techniques Free-blowing and Mold-blowing. The first technique is Free-blowing. This is a method that was the first and is still widely used today as a glass forming technique. The basics of this form is to blow short puffs of air into a glob of glass which is adhered to one end of a blowpipe similar to the way that thick honey would adhere to a straw. By doing the short puffs you end up with more of an elastic skin which makes it easier to shape. By gently blowing, turning and swaying the pipe you can made a great variety of different shapes. One of the best pipes to use for this is the clay blowpipe of about 30-60 cm because it is easy to handle, manipulate and can be re-used several times.
Mold-blowing the newer of the techniques involves a lot of the same basics for free-blowing except that you are your blowing your molten glass glob into a wooden or metal carved shape. This will allow your glass to assume the shape of whatever design your mold has. There are also two main types of molds, the single-piece mold and the multi-piece mold. If you are going to do tableware you would be more apt to use the single-piece mold where if you would want to get into more texture or design variances in your blowing you might want to use the multi-pieced mold.
Getting into the art of glassblowing can be fairly expensive. It's not because of the clay pipes that you need as much as the three types of furnaces that are required. The first being what is referred to as "the furnace," which will initially heat your glass to the proper initial temperature. The second one called the "glory hole" and is mainly used for reheating a piece that you are working on and the final one is called the "annealer." This is a furnace that is used to gradually cool your glass project to prevent it from cracking. Historically all three types were contained in one unit and some cultures still use this method. A few other major items that involved in this art are a marver, which is made from polished steel because it can handle the heat of rolling a warm piece of glass on it, Paddles, used for pushing against the hot glass, tweezers and different types of shears.
If you are ever fortunate to see a master of this craft at work, take the time to watch. It's really amazing what they can do with a glob of melted glass.