Blown Glass by: Jack Loranger


The Studio will be CLOSED Oct 21st and 22nd.  

The Glass Blowing Process

Photos by: Bill McDonald © 2009

The Beginning - The Gather

The preheated stainless steel blowpipe is dipped into 2200F clear molten glass to get a gather.

Air Marver

The pipe is pulled out of the furnace, held horizontally and turned slowly to shape the gather of glass.

Marvering at the Table

The pipe is held horizontally and rolled on the cold stainless steel table to pull most of the glass off the end of the pipe where it can be used in the project. Some pieces of dichroic glass are in the pan waiting to be included in the piece.

Shaping with the Knife

A stainless steel knife is used to pull the hot glass off the pipe and shape it symmetrically.

Starter Bubble

Air is puffed into the pipe while rolling the thumb over the hole to capture a few pounds of pressure in the pipe. The heat of the glass expands the moisture in the breath captured in the pipe and causes a bubble to propagate at the end of the pipe in the center of the glass.

Second Gather

The bubble is dipped into the furnace again for another gather. The glass is about the consistency of honey. The pipe is always turning to keep the glass even.

Rolling in the Frit

The second gather of glass is immediately rolled in cobalt blue crushed glass called frit. The frit sticks to the clear glass to form a dark blue shell over it.

Third Gather

The blue bubble is once again dipped into the clear glass. You cannot see the blue color when it is above about 1300F. At higher temperatures the glass gives out more light than the shop lights so you see no reflective color from the project.

Rolling up the dichroic

The blue bubble with the fresh gather of clear glass is rolled over the top of the broken pieces of dichroic glass. This will be heated until it becomes one with the clear glass.

Swirling the Sparkle

The bubble has been reheated to about 1800F and then taken to the bench. A bent pointy tool is used to drag the surface of the hot glass and swirl the dichroic glass pieces.

Shaping with a Block

A wet wooden block is used to bring the glass back into a symmetrical shape and smooth it out.

Expanding the Bubble

A puff of air expands the bubble enough to complete the symmetry and thin the walls.

Fourth Gather

Clear glass is gathered over the swirled dichroic glass, magnifying the sparkle.

Blowing in the Optic Mold

The bubble, with a fresh gather on it, is placed into the optic mold and air is blown into the pipe to expand the bubble in the mold. The bubble picks up the ridge pattern from the inside of the mold.

Shaping the Neck

A hose is connected to the end of the blow pipe so the bubble can be expanded at the same time that the neck is being shaped with the metal jacks. The top will be squeezed in and stretched to form a neck for the vase. When the neck is long enough, a valley is formed just off the end of the pipe to create a place where the piece can break from the pipe later in the process.

Reheating in the Glory Hole

The piece is once again reheated in the glory hole until it is hot enough to stretch longer and lose some of the diameter. You can see the neckline where the piece will be broken from the pipe.

Torching the Neck

A 200,000 BTU torch is used to heat the neck portion of the vase so it can be stretched a bit further.

Gathering for the Foot

Just the bottom end is dipped twice into the clear glass to get enough fresh glass to shape the foot from.

Papering the Foot

With a piece of wet newspaper in the hand, the thumb is pressed into the center of the fresh hot glass on the bottom and the fingers wrap the side to form the shape of the foot.

Cooling the Neckline

A cold knife is used to cool the neckline down to about 1000F. The rest of the piece is heated to about 1250F. The difference in temperature will help the piece break off where it is intended to.

Preparing the Punty

A stainless steel rod called a "Punty" is dipped into the clear glass and then shaped into a conical shape. This is used to attach to the bottom of the piece so you have something to hold onto it with when it breaks off the pipe.

Opening the Neck and Lip

The punty has been attached to the bottom of the piece and then a few drops of water are used to shatter the glass at the neckline. A tap on the pipe from the tweezers releases the vase from the pipe. The top has been heated to about 1600F and the jacks are used to open the neck and lip of the vase.

Preparing for Break Off - The End

The vase has been flashed in the glory hole a few times to equalize the temperature to about 1250F and then a steel spatula is used to cool a small area between the punty and the bottom of the vase so a few taps on the punty will release it. The vase will be put into a 1000F annealer to anneal and cool slowly over 10-12 hours.