A friend of mine was telling me he had a glass pipe in his collection that was made out of Pyrex glass, so it was tempered and could go from freezing cold temperatures to scorching hot temperatures rapidly. I've never seen one. Anyone heard of anything similar?
I'm pretty sure that's not possible because I remember breaking a pyrex dish as a child by taking it out of the hot oven and rinsing cold water on it.
Basically nothing is unbreakable, and the changing of temperatures certainly makes it more fragile for atleast that time period. We could look at the physics of the material and see why lol. Still, they're kinda cool and definitely a bit more sturdy.
Pyrex doesn't have anything to do with how heat resistant the glass is. There are two basic kinds of glass, called soda-lime, and borosilicate. Borosilicate glass is what 99.9% of all pipes are made out of, and there are a few prevalent 'brands' of boro glass, Pyrex being one of them. The glass for sure isn't tempered, because that involves a thin plasticky coating on the glass which prevents it from breaking into sharp shards of glass if and when it does break. This obviously wouldn't be the case on a pipe because tempered glass would just have the coating burned off when you light it up, and probably release fumes which you don't want to be inhaling. More than likely, your friend has a pipe which has been annealed in a kiln at around 1100 degrees Fahrenheit, in order to remove some of the stress which comes from the expansion and contraction of the glass as it is heated and cooled in the process of making the pipe. Annealing is a very common practice among glassblowers who want to make sure they're putting out quality work, so most pipes you encounter are going to be annealed. Borosilicate glass in general is 'harder' and more heat resistant, so while Pyrex glass is boro, that doesn't mean it's anything special compared to other pipes, unless they're made of soda-lime glass (which is extremely uncommon) Sorry for getting so technical. I'm a glassblower myself, so I'm fairly educated on the subject. Just trying to share some knowledge for the greater good.
Pyrex is actually made with Soda-lime now :/ They quit the Boro glass when they sold out to another company
True and False. Products sold under the Pyrex brand name today are typically soda lime glass which has been tempered to be stronger, but I'm fairly sure they do still have a few boro production lines. Not 100% about that though. However, Corning itself (the company which made boro Pyrex dishes before 'selling out') does still continue to produce and sell borosilicate glass in a 'raw' form. You can buy rods and tubes of borosilicate Pyrex glass for use as a medium in glassworks. It's not as common, but there are people who still make pipes with brand-name Pyrex glass. Not like it's going to say that on the pipe, the only way to really tell the difference is to know the artist, but it is still out there. As a glassblower, I've seen a LOT of glass pipes in my day to day life, and never once have I seen one made out of soda lime (a.k.a. soft glass).
I'm also a glassblower. The company Corning sold pyrex to uses sodalime now under the pyrex name. Corning still produces tubes and rods in boro ya. Let me get your page/shop on facebook/etsy I'll check out your work maybe we can do something together.