How to Blow Glass in One Easy Lesson:

All blown glass is formed by a ‘layering’ process. That is, a building up of layers of glass from the inside out. The blowpipe is dipped into a crucible of glass and a small amount glass is ‘gathered’ onto the blowpipe. This process is similar to getting ‘honey on a stick’. Just as with the honey, the glass has to be prevented from ‘falling of the pipe’ by constantly turning the pipe to counter the force of gravity. The glass is shaped into a spherical shape with the aid of wet wooden tools called - blocks. The glass cools quickly to the point were it won’t move anymore. It can then be dipped back into the pot of glass or a pot with a different color of glass to get a second layer (gather). This process can be repeated as many times as necessary to build up the required mass.

At any point in the layering process, a decorative pattern may be applied using colored or opalescent glass. The vases and the small faceted bottle have what is called a ‘feather’ pattern. It is done by applying a spiral line of glass on the surface of one of the layers. The piece is then heated again to the point where the glass can be manipulated and the lines are ‘pulled’ or dragged with the aid of various tools such as common kitchen knives or ice picks with a bent or ‘hooked’ tip. This is similar to how a pastry chef makes decorative patterns on pastries by ‘dragging’ a knife through lines of frosting. Is this case, the ‘frosting’ is about 20000 . This can be done on what will be the surface of the piece as in the case of the lavender vases with the white opal line patterns or it can be ‘cased’ within another layer of glass as in the small faceted bottle.

The Piece must be repeatedly re-heated to keep the glass pliable. In most cases, there is a process where the piece is ‘transferred from the blowpipe to a solid rod called a ‘puntil’ (pronounced - punty). This is done by ‘sticking’ the end of the puntil onto the bottom of the piece with the aid of a small amount of hot glass ‘gathered’ onto the end of the rod. The piece is literally ‘broken’ off the end of the pipe thus exposing what will be the top of the piece. The opening or top of the piece can then be re-heated to trim and shape the opening of the piece.

After the piece is shaped, it must be cooled slowly or ‘annealed’. It is placed into an oven at about 1000 degrees (F.) and slowly cooled to room teperature, usually overnight to relieve any ‘stress’. If the piece is allowed to cool without this ‘annealing process, it would shatter.

The ‘faceted’ pieces are done after the pieces are cooled by cutting away the surface to the desired shape. This is done on large grinding wheels using a slurry of silicon carbide grinding material. The process must be repeated through several steps using repeatedly finer grinding material. It finally goes though a polishing process to bring these areas back to a high polish. Some pieces are frosted or acid etched using a hydrofluoric acid bath. The pieces such as the larger faceted bottle utilize ‘curved’ facets which are much more difficult to execute. These pieces require a much greater degree of skill and are much more time consuming especially in the polishing stage.

All work is designed and executed personally by James Clarke who has created works of Art-Glass in Boulder Colorado for the past 18 years.

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