Originally Posted by jrhoades
hey yall i was wondering what your thoughts were on a glass bowl, i was just thinking about it and i dont know if it would crack from the heat or not, so i thought id ask if anyones seen one? thanks
heres your intro to basic glass
you have 2 major types of glass you interact with in every day life. borosilica glass (lab ware, pyrex, and most of your cook ware type glass, small glass art and glass pipes) and soda lime glass (windows, bottles, most cups, your hookah bases, hand blown glass).
borosilica glass is silica and boric acid (IIRC) which acts as the flux which breaks the silica down to let it melt at a much lower temp (pure silica melts at like 4-6k*F), soda lime glass is silica and soda ash and lime as the fluxes. the soda lime glass is easier to work by hand yet will not take thermal shock or physical shock as well when finished where as your borosilica glass can withstand a hell of a lot more.
all the glass bowls will be pyrex or borosilica of some kind to withstand the heat and thermal changes and the shocks it will get.
all this being said you can still have a piece of borosilica glass that cracks randomly because glass is not perfect (there are micro cracks all over glass that allow it to crack, if you could have theoretically perfect glass it would be basically impossible to crack). a lot of the issues you will run into though is the craftsperson or artist who made it messed up and didnt anneal (taking it from 900-1000*f to room temp slowly to allow the stress to come out of the glass)
Originally Posted by tic-tac
Are you sure of this? Maybe the industrial hookahs are made as you say but I do not think artisans in Turkey, Syria or Egypt use this kind of glass...
bowls not bases. all glass bowls are borosilica glass (pyrex is one formula and a trade name), bases are all going to be a soda lime glass which can handle less thermal shock and is usually a "softer" glass