Venting a Kiln

Venting a kiln is not something you will do with most of your firings.

What are the different types of venting and when are they used?

That is what this page will cover, hopefully to help you understand the process and when it is employed.

Venting the kiln basically means opening the kiln door or lid during the glass fusing process.

When glass fusing, there are two primary types of venting.

These venting processes are referred to as the wedge vent and the flash vent.

Remember to always practice safety precautions when opening and closing the kiln.

Wear protective gloves to prevent burns and safety glasses to safeguard your eyes.

Wedge Venting

This process involves opening the kiln lid or door using a wedge that is about ½ to 1 inch.

This process has a couple of purposes.

By having the lid or door open, it helps as an exhaust system.

This opening allows fumes from either glues or other burning organic material to escape the kiln.

Sometimes these fumes can contaminate the surface of the glass as it is being fired.

The other purpose is to minimize thermal shock by allowing the heating process to be slowed down.

Once the kiln temperature reaches about 900 degrees Fahrenheit, the wedge can be removed.

Flash Venting

venting a kiln, wedge venting, flash venting

Flash venting is also known as crash cooling .

This procedure is used to almost freeze or discontinue the heating process.

When the piece being fused has reached the desired look, the kiln is turned off and the kiln is opened wide for a few seconds to end or freeze the fusing process.

The kiln is turned off during this process, otherwise the kiln will continue to heat up and the piece will resume slumping or melting further.

By opening the kiln door or lid, this allows enough heat to escape out of the kiln to cease the process.

The suggested time for venting the kiln is:

  • Fusing: Turn off the kiln power. Wearing protective gloves, open the kiln lid or door for about 8 seconds, then close the lid or door.
  • Slumping: Turn off the kiln power. Wearing protective gloves, open the kiln lid or door for about 3 seconds, then close the lid or door.
  • Opening the door and allowing the heat to escape will not harm the glass as long as the temperature stays at or above 1100 degrees Fahrenheit.

    Glass is not at the risk of thermal shock in its workable or fluid zones.

    Be sure to close the lid or door before the temperature plummets below 1100 degrees Fahrenheit.

    Venting a kiln is a process that you might find very helpful and sometimes necessary in the glass fusing process.

    Use precaution in your venting process to maintain your safety and artwork.

    Return from this page to one of the following pages:

    Crash Cooling

    Technical Terms

    Venting a Kiln to Glass Fusing Made Easy

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