When you have a standard lighter, you certainly know that it can be a risk to light anything made of plastic or other similar substances, but what about glass? Can the Bic in your pocket actually cause a glass pipe or other glass based item to melt?
The answer is no, but there are many torch and butane lighters out there that can. So how hot does it really need to be in order to do this, and what type of lighter would you have to use?
The average melting point of glass is somewhere around 1500 degrees Celsius. This is certainly hotter than most lighters get, and it would take quite a bit of time to heat the glass to this point. If you are looking to melt glass, however, you will find that you have to choose lighters that can offer a sustained flame that burns at a very high temperature. There are lighters out there designed to burn up to 2500 degrees Celsius, so it is certainly possible to find one that is up to the task if you have a project that involves melting glass.
One reason that most lighters will not melt glass is that they are simply not hot enough. Another reason is that they would have to remain lit for a significant period of time in order to heat glass to the melting point and they would become too hot to use long before this occurred. If the flame goes out and needs to be relit, you will find that the glass will cool so rapidly as to make it all but impossible to be melted in this fashion. Because of this, most lighters are simply ineffective at this task.
If you want to use lighters to melt glass, a butane torch is really the only option, and you will need to find one that burns consistently at a temperature above about 1600 degrees Celsius. These models are designed to be safe when lit for prolonged periods of time, taking away the risk of burns and explosion. With the right model, you can indeed melt glass, though specific glass melting torches will always be better for the task. If you are looking to create a decorative glass item or just to experiment with the principles of science, buying the right lighters for the job is going to be the most important step.