Nomad
05-20-2016, 12:15 PM
I was interviewed by a 3rd grade student who is doing a project on jobs she can do as an adult.
How do you think I did?
Yes Rachael I would love to answer your questions.
Rachael:
I read that if glass cools too fast it can explode, how does it not cool too fast?
Yes glass will crack and sometimes explode when the temperature becomes too hot or too cold too fast. It is called the thermal rate of expansion. This refers to the ratio of how fast you can heat and cool a piece of glass depending on it's thickness.
In order to make it so that the glass does not brake you have to cool the glass in a kiln. To do this you soak it at 1050 degrees Fahrenheit. You bake the glass for a time determined by the thermal rate of expansion ratio. For example you bake the glass for 30 minutes if it is about ¼ inch thick. This is for Pyrex or borosilicate glass. Then you can shut down the kiln and leave the door closed for it to slow cool over night.
Once the glass is heated slowly up to 1050 you can then heat it very fast to it's melting point which is about 2300 degrees. But you can not let it cool below 1050 degrees or it will brake.
I read what glass was made of and one of the things was soda ash.* What is soda ash?
Soft glass or glass that we make drinking glasses out of is made of silica or sand, lime, and ash. It is mostly made of silica but has a few ingredients to add other properties like how soft or hard it is when it is molten to it.
Pyrex glass or borosilicate is made with boron. This makes it so you can heat it faster and it does not break. Coffee pots and things like that are made from it.
If you were to make glass from sand, which some people do, you would need to buy batch to melt in a furnace at 2300 degrees. Batch is premixed sand, lime stone and ash. It is dangerous to breath in. So you have to wear a mask when you handle it. So most glassblowers will use recycled glass from factories. They remelt it and it works great. That is called cullet.
I use borosilicate mostly. It comes in rods and tubes in clear and color already made. I just melt it and shape it with my torch. I do what is called lampworking.
What is the most important tool you have?
I would say it is my torch. I use it all the time.
Have you ever had a scary thing happen making glass?
I have cut my hand before and caught my pants on fire a couple times. I burned myself before also. But nothing too major. As long as you focus on what you are doing it is safe for the most part.
Good book to read is called “Contemporary Lampworking” by Bandhu Scott Dunham
Video of my making a Ornament. It is in high speed:
https://youtu.be/knArOL6YnpE
How do you think I did?
Yes Rachael I would love to answer your questions.
Rachael:
I read that if glass cools too fast it can explode, how does it not cool too fast?
Yes glass will crack and sometimes explode when the temperature becomes too hot or too cold too fast. It is called the thermal rate of expansion. This refers to the ratio of how fast you can heat and cool a piece of glass depending on it's thickness.
In order to make it so that the glass does not brake you have to cool the glass in a kiln. To do this you soak it at 1050 degrees Fahrenheit. You bake the glass for a time determined by the thermal rate of expansion ratio. For example you bake the glass for 30 minutes if it is about ¼ inch thick. This is for Pyrex or borosilicate glass. Then you can shut down the kiln and leave the door closed for it to slow cool over night.
Once the glass is heated slowly up to 1050 you can then heat it very fast to it's melting point which is about 2300 degrees. But you can not let it cool below 1050 degrees or it will brake.
I read what glass was made of and one of the things was soda ash.* What is soda ash?
Soft glass or glass that we make drinking glasses out of is made of silica or sand, lime, and ash. It is mostly made of silica but has a few ingredients to add other properties like how soft or hard it is when it is molten to it.
Pyrex glass or borosilicate is made with boron. This makes it so you can heat it faster and it does not break. Coffee pots and things like that are made from it.
If you were to make glass from sand, which some people do, you would need to buy batch to melt in a furnace at 2300 degrees. Batch is premixed sand, lime stone and ash. It is dangerous to breath in. So you have to wear a mask when you handle it. So most glassblowers will use recycled glass from factories. They remelt it and it works great. That is called cullet.
I use borosilicate mostly. It comes in rods and tubes in clear and color already made. I just melt it and shape it with my torch. I do what is called lampworking.
What is the most important tool you have?
I would say it is my torch. I use it all the time.
Have you ever had a scary thing happen making glass?
I have cut my hand before and caught my pants on fire a couple times. I burned myself before also. But nothing too major. As long as you focus on what you are doing it is safe for the most part.
Good book to read is called “Contemporary Lampworking” by Bandhu Scott Dunham
Video of my making a Ornament. It is in high speed:
https://youtu.be/knArOL6YnpE