What is a Hot Shop?

Welcome to the "Hot Shop," a glassblowing studio buzzing with specialized tools and equipment. In this blog post, I'll guide you through the essentials of the hot shop and how glass artists use it to transform molten glass into stunning art pieces.

 

BONUS
Shannie’s Hot Shop Scavenger Hunt!

Spot all the tools and equipment in the video at the bottom of this page! Once Complete, email your scorecard to shannieartandglass@gmail.com. Score 100% and receive a discount code for my online store!

Happy Hunting!

 
 

What is a Hot Shop?

 

General Layout and Atmosphere

The Hot Shop Studio space

The studio typically has an open floor plan with areas dedicated to each stage of glassblowing. Due to the high temperatures required for glassworking, the atmosphere is warm, often quite hot, with bright lighting for detailed work. The air carries the distinct scent of hot glass, metal, and wood.

 

Key Machines and Tools

Furnace

The furnace is the heart of the glassblowing studio. It melts the raw glass at extremely high temperatures, typically around 2200°F (1150°C). Glass artists gather molten glass from the furnace using a blowpipe or punty rod. They dip the end of the rod into the furnace, twisting it to collect a gob of molten glass. Similar to how you would get honey out of a jar with a knife.

Reheating Chamber

A high-temperature reheating chamber used to keep the glass hot and workable during the shaping process. As soon as the glass is removed from the furnace and held out in the ambient air, it cools down rapidly. Artists frequently return their work-in-progress to the chamber to reheat the glass to maintain its pliability. This process is repeated many times to keep the glass at a workable temperature. The consistency of glass is similar to honey; the hotter it is, the easier it is to work with.

Annealer

The annealing oven cools glass objects gradually and systematically to relieve internal stresses. After shaping, glass pieces are placed in the annealer to cool down slowly over several hours or even days. This prevents the glass from cracking due to thermal shock. This slow cooling process changes the molecular structure of the glass to strengthen it and crystalize the molecules as they cool.

Garage

The garage is a temperature-controlled kiln that holds partially worked glass pieces at a stable temperature. This allows glassblowers to pause their work and reheat the glass later without it cracking or losing its integrity. The garage maintains the glass at a workable temperature, preventing thermal shock and enabling artists to work on complex projects over extended periods.

Marver

The marver is a flat, smooth, steel-top surface used to shape and cool the glass. Artists roll the molten glass on the marver to shape or apply color to the glass. The marver can also help cool the glass slightly by removing any heat where the glass touches the cold metal, making it easier to handle.

Bench With Arm Rests

This is no ordinary bench. It is designed explicitly for glassworking. It is a workbench with extended arms used to support the blowpipe or punty rod while the artist works on the glass. Artists sit at the bench, resting the blowpipe on the arms, and use various tools to shape and manipulate the glass. The bench provides stability and precision during the process.

Pipe Warmer

The primary function of a pipe warmer is to preheat blowpipes, a crucial step in preventing thermal shock when they come into contact with molten glass. The heat on the end of a blowpipe also plays a role in anchoring the glass to the pipe.

Pipe Cooler

A pipe cooler is used to cool down blowpipes before and during the process of handling molten glass. The pipe cooler is simply a fountain-like water container that helps manage the pipes' temperature. This makes the rods safe to hold and prevents overheating that could damage the tools, the artist’s hands, or affect the glassworking process.

Blowpipe

A blowpipe is a long, hollow metal tube used to gather and blow glass. Simply put, the blowpipe is a big metal straw. Artists gather molten glass on the end of the blowpipe and blow into it to create bubbles and shapes.

Punty Rod

A punty rod is a solid metal rod used to hold and manipulate glass pieces during the working process. It is used primarily to support the piece when it needs to be worked on the opposite end, often for finishing touches.

Blocks

Wooden cups soaked in water are used to shape the glass. Artists roll the hot glass into the block to achieve smooth, rounded shapes. Simply put, blocks are big, wet, wooden spoons that shape the glass by rolling it inside the carved-out shape within the block. They are often made of fruit tree woods, such as cherry wood because they are dense and will last longer when in direct contact with molten glass.

Jacks

Jacks are large tweezer-like tools used for shaping, cutting, and creating patterns in the glass. Artists use jacks to constrict areas of the glass and refine shapes.

Shears

Shears are scissors designed to cut hot glass. Artists use shears to trim excess glass or to make precise cuts in the molten material. Several types of shears, such as diamond shears, are designed specifically for unique functions or cuts.

Newspaper

In a glassblowing studio, folded newspaper is used to shape and smooth hot glass. The newspaper is typically folded and dampened, allowing glassblowers to handle the molten glass more directly. This method provides a soft, flexible pad-like tool that helps refine the shape of the glass while protecting it from direct contact with metal tools, which could leave marks or cause thermal shock.

Blow Hose

A blow hose is a flexible hose attached to the blowpipe, allowing continuous blowing without removing the pipe from the bench. Artists working solo use the puffer to inflate the glass while simultaneously using both hands to shape and manipulate it. Often, glassblowing is a team sport, but sometimes, an artist will work alone with the help of a blow hose.

 

Color and Decoration Tools

Frit

Frit is crushed pieces of colored glass used for decorating. It can come in a range of sizes, from fine powder to chunks the size of gravel. The size an artist uses depends on the design or look they want to achieve. Artists roll molten glass in frit to apply colors and patterns. They often place frits in metal trays or straight on the marver, taking care not to spill them on the floor and contaminate them.

Color Bars

Color bars are solid sticks of colored glass, used in glass-blowing to add vibrant hues to creations. These rods are melted and incorporated into the molten clear glass to create patterns, designs, or uniform colors. Glass blowers can fuse the color rods with the clear glass with heat to manipulate them, forming intricate designs, or pull and stretch them to create detailed lines and shapes.

Frit Sifter

Similar to how a cook sifts flour, these containers have mesh tops and are used to sprinkle powdered glass colors. Artists use powder shakers to apply fine, even layers of color to their work.

Torch

Artists use a large torch to equalize the heat of the glass closest to the pipe and a small torch for intricate work, such as adding small details or making repairs. Torches are used between large overall heats on the reheating chamber.

MAPP Gas

MAPP gas stands for Methyl Acetylene Propadiene Propane, which is known for its high heat output. MAPP gas is used in glassblowing studios because it burns hot and efficiently. It powers torches for quickly melting and shaping glass, perfect for detailed work. Its fast heating allows for quick repairs without needing a furnace. Overall, MAPP gas makes glassblowing faster and more precise.

 

Safety and Comfort

Protective Gear

The protective gear used in a hot shop includes various garments: heat-resistant gloves (Kevlar), safety glasses, face shields, and sleeves. These articles of clothing are essential for protecting artists from burns, glass shards, and intense heat.

Didymium Glasses

Didymium glasses are essential for glass-blowing because they filter out the bright sodium flare, making it easier to see details and reducing eye strain. They block harmful UV and IR radiation, protect the eyes, and enhance color perception, allowing glass-blowers to more accurately judge the temperature of the glass. This protects the artist’s eyes and enables glass-blowers to work more comfortably for more extended periods.

Ventilation System

This HVAC system ensures the studio is well-ventilated to remove fumes and glass powder and maintain air quality. The ventilation system constantly runs to keep the environment safe and comfortable.

Wooden Paddles

Wooden paddles are crucial in glassblowing for shaping molten glass and smoothing surfaces. Made from heat-resistant hardwoods like cherry or maple, they also serve as effective heat shields, protecting glassblowers from radiant heat while allowing precise temperature control and shaping of the glass.

Outside the Hot Shop

Cold Shop

After pieces are removed from the annealer, they are often moved to a designated cooling and finishing area. Here, artists inspect their work, polish any rough edges, and add final touches. This area is equipped with grinders, polishers, and other finishing tools. It is called a cold shop because artists work on their glass pieces after they have cooled down. They are considered “cold” because they can be handled with bare hands. However, artists must remember that glass can be sharp when cold before it has been polished!

Conclusion

The combination of high temperatures, precise tools, and skilled artistry creates an environment where creativity and craftsmanship come together to produce stunning works of glass art. A glassblowing studio is a meticulously organized space where each machine and tool plays a vital role. Of course, the tools discussed above are only the essentials—more specialized projects call for even more specialized tools!

Dont Forget!

Participate in the scavenger hunt! Try to spot all the tools and equipment in the video below. When you've completed the scavenger hunt, email your scorecard to shannieartandglass@gmail.com. Score 100% and receive a discount code for my online store. Happy hunting!

Just in case you missed it…

Thank You for Participating!

Be on the lookout for new blog posts on the 18th of every month!

 
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