Glass is a breathtaking object. And though the process of making glass seems hip and modern, the practice of glassmaking can actually be traced up in ancient times. In fact, it was the first century Syrians who had discovered when they learned it could be heated, blown from one end of a pipe, and turned into various stuff.
And in the 15th-16th century, Italian glass (Murano/Venetian Glass) was highly prized that the elites feared it might surpass the value of gold.
Since then, glass smiths have learned to adapt modern and technically intricate techniques and combined them with proven methods to better their work.
And if you’re interested to know more, then we suggest that you keep reading as we are going to give a closer look at the common glass blowing techniques for making glass in today’s blog post.
Time To Blow
Today, there are several techniques used by smiths to blow glass. But the tools they used (tongs, pincers, tweezers, etc.) remain the same since ancient times.
So with no further ado, here are the most common glass blowing techniques that are used by most glass makers to shape and mold glass:
First, a batch of glass is placed inside a pot or crucible. Then the pot is heated in the initial furnace to undergo the “Charging” process or the method of melting large amounts of glasses at temperatures of 2000 degrees Fahrenheit or higher. This turns the glass into a molten substance that is ideal for molding.
While glassblowing is usually done individually, it requires a team of smiths to pull off this feat as blowing glass is very challenging. When the glass is melted to the desired temperature, the gaffer (lead glassblower) will take a blowpipe and dip it into the furnace. A glob of molten glass will then come out and the gaffer will try to secure it properly while dipping the other end of the pipe with water to cool it off.
Once ready, the gaffer will blow through the pipe to create a bubble of glass. And whenever he’s not blowing, the other end of the pipe is capped so the hot air will remain inside the bubble and keep it in shape. Then, layers of glass are added by dipping it back to the molten batch or using a gathering iron.
The glass artisans will then shape the glass through a marver by rolling it to the desired shape. They will also use certain tools like a block (a wetted wood shaping tool) and a jack for detailed shaping. Paddles and heat shields are also used to protect the artisan from extreme heat. The paddles can also be utilized as a smoothing tool while tweezers are also used to manipulate the glass into intricate shapes.
The parison (or partially-blown glass) is now rolled around the marver while bits of glasses are slowly added using a tool called a punty. It’s also in this time when various colorants are added. Also, different pieces of glass can be joined through a process of lamination (using adhesive or heat) while warps and threads can be laid as the glass is turned to created decorative patterns.
While the glass is formed, the base of the bubble glass is attached to a tool called a pontil while the mouth is being shaped. The pontil mark is usually removed either by grounding or polishing afterwards.
The Glory Hole
The blown glass will then be inserted in the second furnace or “The Glory Hole” to raise the temperature again. The artisan will travel back and forth to maintain the ideal blowing temperature.
And for the last step of the glass blowing techniques, the blown glass will be taken to the third furnace or the annealer. This is the most crucial step as it ensures the piece is properly cooled down and retains its final shape as it transforms from viscous to solid glass.
Sometimes, a pyrometer is also used to keep the correct temperature during annealing and prevent internal strain that might cause the blown glass to become unstable and break down.
Finally, the finished product will then be delivered to the cold shop for grounding, polishing, and detailing.