Bending a glass tube experiment


The experimentation of bending a glass tube provides information about the nature of glass as well as its inherent qualities. Glass has historically been utilized for ornamental purposes, but it is also employed as a transparent barrier that allows for reasonably safe inspection. While many other types of glass may be created, we will be dealing with the most common, widely manufactured glass, which is highly bendable when heated. Glass is an amorphous, crystalline material that must be handled carefully with the Bunsen burner to bend it properly without hindrance or unintentional breakage.


Learn, comprehend, but also commit to memory the easy method of bending a glass tube experiment.

Materials required

This experiment requires a bunsen burner as well as a long soda-glass tube (20 to 25 cm).


  • Hold the soda-glass tube (by the edges) then place it over the burner's blaze.

  • Concentrate the heating on 1 portion of the tube.

  • Spin the glass tube with your fingers to make sure that the glass is uniformly heated for optimal softening.

  • Once the tube has been properly softened, make sure you know which side it has to be bent.

  • When the glass has attained the desired form, just withdraw it from the flame then switch off the burner if it is no longer needed.

  • Allow the glass to cool by placing it down (be careful to only place it on a glazed tile to avoid damage to the surface)

Images Coming soon

Precautions to take

  • While completing the experiment, keep your hands at least four to five cm away from the burner flame as well as the place of bending of the tube.

  • The glass should be held as far away from the face but as far away from the body as feasible.

  • It is critical not to attempt to bend the tube by strength before it becomes red hot yet pliable enough to bend; doing so could result in the glass breaking and causing harm.


The glass is extremely brittle at normal temperature, thus also is known to fracture easily. Nonetheless, an amorphous crystalline solid, such as glass, has special properties that enable it to flex when exposed to extreme heat. And of how flexible glass is or how easily it could be bent in the right direction with the right amount of heat, this experiment can imply that substances like glass have a wide range of applications.


Q1. Why can't we move the glass until it's finished?

Ans. Because glass is a solid, brittle, amorphous, crystalline substance, it cannot be bent without shattering in its usual condition. Glass may be bent at temperatures considerably below its melting point, but any effort to bend it once it softens can result in an incorrect band or indeed shattering. Because this technique involves a fragile tube of soda glass, it is critical to bend the glass gently with as little force as possible. The red-hot area of the glass will be flexible enough just to bend to the appropriate form once the glass has cooled sufficiently.

Q2. Why is it necessary to spin the glass tube consistently when heating?

Ans. Whenever the heat hits the tube equally, the tube will acquire its shape. Spinning the glass tube evenly during heating ensures that both surfaces of the tube receive an equal quantity of heat. If one tries to alter the glass with strength without first heating it properly, it may break unexpectedly. The heat changes the characteristics of glass. Simply make it flexible enough to take shape, such that if one section absorbs more warmth than the other, there will be deformation in the form as well as the possibility of shattered glass.

Q3. What happens if you put red hot glasses in water rather than a glazed tile?

Ans. Once the gas is heated to red hot, it is best to let it cool gently on its own. Trying to accelerate the process with water will fracture it, or in some circumstances explode it. As a result, it is not recommended to let any type of water near the glass while it is cooling on glazed tile. Glass grows significantly when heated, but instead abruptly cooling it in such a state results in non-uniform compression on a molecular level, this causes it to shatter.

Q4. What are all the applications for bent glass?


  • Bent glass, like conventional glass, may operate as a thermal insulator, leaving it incapable of conducting heat or electricity. Instead, the glass resists heat, making it a fantastic heat insulator, which means it can trap heat - ideal for the cold weather of the year.

  • Curved glass has several aesthetic plus functional applications. Curved glass is being used externally in skyscrapers as well as other storefronts, and building facades including windows. Internally, it is utilized in bathroom doors, elevator glass panels, exhibits, enclosures also among room dividers. Curved glass is also used in a variety of architectural applications, including barrel vaults, domes, aquariums, rotating doors, and even solariums.

  • Curved glass is an excellent non-traditional alternative to regular glass applications. Glass is ecologically benign, visually appealing, yet thermally insulating while also providing structural advantages - ideal for construction functions. The possibilities for twisted glass are limitless.

Q5. What are some of the issues but also solutions for glass tubes?


  • Glass Won't Soften - This occurs when the flame temperature is insufficient to warm the glass. A hotter fuel, such as gas, is the remedy.

  • Glass Softens Too Quickly - This is achieved by employing too much heat. Reduce the amount of time the glass is in the heat, move it away from the hottest section of the flame, or even use a fuel source with a cooler flame.

  • Glass Has Bumps and sometimes Crimps - This can be caused by folding the glass more than once or by allowing it to get overly soft, causing its weight to drag it down. The solution to this challenge is expertise as well as practice because understanding when to withdraw the glass from the flame to bend or pull it requires some art. Just keep in mind that bending/pulling is a one-time thing. If that doesn't work, it's doubtful that you'll be able to reheat the glass to achieve a better result.

  • Glass Tubing Seals - If the interior of the tube seals, the glass has become too heated. Withdraw the glass from the heat quickly if you are bending it. Allow the glass to cool a little further before sketching it. Keep in mind that you'll want to purposefully seal the glass. If you do, simply rotate the tube in the flame until it closes shut.

Updated on: 14-Dec-2022


Kickstart Your Career

Get certified by completing the course

Get Started